Gentlemen,

I am new to this forum and this is my first post. I have decided
to start loading my own cartridges in my favorite caliber (7mm
Remington Magnum). I have purchased a full reloading kit (Redding)
and red several reloading handbooks (Nosler, Hornady, Speer,
Swift) to familiarize myself with the process.

Here is my questions for you experts:

Do I have to use the exact brand of brass and primer as mentioned
in the reloading manuals?

It is my impression that it's OK to use other brands of primer
(say Winchster Long Rifle Magnum instead of Federal 215 magnum)
and brass (say Norma instead of Remington) as long as I start with
the minimum loads. I will be using the exact bullet and powder as
mentioned in the handbooks otherwise.

I look forward to your comments.

Thank you.

-Omid

You don't have to use the exact brand of brass and primers, but you do need to know that changing those componets most likely will effect what the maximum load will be in your rifle.

I consider a chronograph an essential safety tool when working up loads, especially when you change componets. When you achieve the max velocity from the printed data, correlated for barrel length, consider that your max. You may achieve that velocity with the same powder charge, a bit less powder, or perhaps a tad more.

OK, thank you very much. I do have a choronograph so I can do the test you mentioned.

My rifle is a new Mauser M03 and I will stop as soon as I find a load with sufficient acurracy. Hopefully, this point will be reached before exceeding the maximum load.

You do not need to use the same exact stuff that is in the manual, but you do need to take extra care when switching to a different type of component. Most ammo has a bit of leeway, a 1/10 of a grain up or down wont make a difference for a hunting round, swapping from fed to CCI primers won't matter,etc. More care should be taken with magnum loads, and no deviation should be done with the big bores.

Reduce the load up to 10% when using military brass, take extra care when going from standard to mag primers, or mag to standard primers, etc

The most important thing is good habits and to always reload when you can work uninterupted.

The smallest case I have worked up to failure with standard and magnum primers is the 25acp with 50 gr FMJ and Alliant Bullseye:
1) Max published load 1.2 gr
2) WSP #1-1/2 - 108 Small Regular Pistol 4.3 gr Bullseye primer falls out .020" extractor groove growth
3) WSPM #1-1/2 - 108 Small Magnum Pistol 3.2 gr Bullseye primer falls out .023" extractor groove growth
---------------------------------------------------------------------------------------------------------
standard primer + 1.1 gr Bullseye = magnum primer

This is probably a non linear relationship, and I would not get the same velocity at zero powder with magnum primer. This equation is only valid for pressure, not velocity, and only at the point of case failure.

I would say that it is only valid to for that size case, but IIRC, 9mm 115 gr JHP shows the same 1.1 ~ 1.5 gr AA#5 difference of between standard and magnum primers at the point of case failure.



http://www.winchester.com/products/catalog/components/dataprimers.aspx

Thanks for the aditional comments. As I said, I am just using different brass and different primer. Other components (poweder and bullet) are exactly as said in the books and I am going to load to the "starting load" not the maximum.

Just one more question:

The Hodgdon reloading manual shows all loading data for 7mm Remington Magnum using Winchster LR primers. Shouldn't one use Win LR magnum primers for this caliber? Is it a typo or is it correct?

The key, as I am sure you are gathering, is to start at the minimum and work up. This is potentially dangerous business so, if you are partial to your eyes and fingers, you will heed that advice. Shooting a rifle is setting off a controlled 65,000 psi explosion.

As far as your second question goes, I think there are several opinions on that. Some are partial to magnum primers in cold weather, some are partial to magnum primers for ball powders, some like magnum primers generally. You might contact Hodgdon and ask them. Even if they specify only Large Rifle and not magnum you can likely use magnum safely IF YOU WORK UP CAREFULLY. (Notice the consistent theme here?)

LWD

quote:

Originally posted by Omid:
Do I have to use the exact brand of brass and primer as mentioned
in the reloading manuals?

It is my impression that it's OK to use other brands of primer
(say Winchster Long Rifle Magnum instead of Federal 215 magnum)
and brass (say Norma instead of Remington) as long as I start with
the minimum loads. I will be using the exact bullet and powder as
mentioned in the handbooks otherwise.

I look forward to your comments.

Thank you.

-Omid

Omid,

Since you have a chono - Here's a common sense check on pressure:

If you exceed the max. listed velocity for a given powder and barrel length, there's a real good chance you have also exceeded the max. pressure!

Now that I am home, I have looked at my manuals and only one, the Barnes #3, lists a standard, not magnum, primer.

LWD

quote:

Originally posted by Omid:
OK, thank you very much. I do have a choronograph so I can do the test you mentioned.

My rifle is a new Mauser M03 and I will stop as soon as I find a load with sufficient acurracy. Hopefully, this point will be reached before exceeding the maximum load.

I did not catch that M03 at first
http://www.mauser-usa.net/




With the 1898 Mauser design, I am absolutely fearless in a load work up.

I load the ammo in increments of 1 gr.
I start at the bottom and keep shooting until the primer leaks, or pierces, or the bolt get hard to lift. That establishes the limit and I stop there.

Then I go home a back off a couple grains from that limit load, load 20 rounds of it, and go back to the range again, and test for accuracy.

http://data.hodgdon.com/cartridge_load.asp
Hodgdon says:

quote:

175 GR. NOS PART 175 H4831 .284" 3.290" 58.0 2660 50,200 CUP

I do 65 gr H4831SC 175 gr and get 2850 fps with a 26" barrel.
Quickload thinks that I should get 2847 fps @ 52,808 psi.
Quickload thinks Hodgdon should be getting 2513 fps with a 24" barrel @39,564 psi

7mm Mag is registered with SAAMI at 61,000 psi average and 79,300 to 85,400 psi proof pressure.

What does it all mean?
Those Hodgdon loads are wimpy and unrealistic.
Maybe you should learn how to work up loads.

I use large rifle as opposed to large rifle magnum primers with Reloader 22 for the 7mm Remington Magnum; this gives excellent accuracy.

In a case the size of the 7mm Remington Magnum, I've never found appreciable differences in pressure when going from standard to magnum primers. Also, I've not found switching brass brands to make any appreciable pressure difference in this cartridge. If there was 7mm Remington Magnum military brass (which there isn't), then I would anticipate that a 1.5 to 2 grain drop in powder charge would be needed.

I've also never used a chronograph in working up loads. It's a useful tool I'm sure but I've used mine only to satisfy my curiosity as to how fast my bullets are going. I load for accuracy and not for velocity. This means that in almost all cases, I end up with loads a bit below maximum recommended loads.

quote:

Originally posted by Omid:
The Hodgdon reloading manual shows all loading data for 7mm Remington Magnum using Winchster LR primers. Shouldn't one use Win LR magnum primers for this caliber? Is it a typo or is it correct?

Primers vari between manfactures, the Win LR primers have a lot of "poke" to them, in some cases even more "poke" than other companies "Magnum" primers.
At one point Winchester packaged them as "LR/LRM" IOW a HOT regular = mild mag.

As far as the case brand goes, the smaller the internal capacity, the less powder that is required to reach the same pressure/velocity. This becomes a concern when you start to believe that the guys with all the test equipment don't know as much as you do, and you start out at the MAX charge with a case that has a smaller capacity than the one they worked up the data with.
As your just starting out, try to stick with "book" spec's, as much as possible. Once you have a few Min to Max "work-ups" under your belt, than you can start to think about changing components like case and primer brand. You need to learn for yourself what the approaching danger signs are, and the only way to do that is slowly increasing the powder charge and keeping a critical eye on every detail of the fired case. IOW you need to learn how to walk, before you try to run.

quote:

Originally posted by Grumulkin:
...I've also never used a chronograph in working up loads. It's a useful tool I'm sure but I've used mine only to satisfy my curiosity as to how fast my bullets are going. ...

Hey Omid, I completely agree with Grumulkin on the proper use for a chronograph. There is a common misperception that looking at a "Velocity" tells you anything useful about Pressure.

If you get the exact Velocity listed in a Manual with a specific load, you know for absolutely positively sure that:
1. The Pressure may be WAY HIGER than expected.
2. The Pressure may be the same as predicted(very unlikely).
3. The Pressure may be WAY LOWER than expected.

Chronographs are excellent tools for telling Velocity, but they don't tell what the Pressure is.

Hot Core,
You have got a good speal, but if you want to tour American with it, you need a straight guy with a theme song, costume, and dance.
Your plucky comic relief singing and dancing side kick could be 'chonograph work up man'.


How about:

[to the tune of Fortuneteller]
Work'n up a load with chronograph
Hot Core knows I'm out a my gourd
Guys at the range are start'n to laugh
It's just like use'n a Ouija Board.

Where in the world did I learn to think?
I pull my thoughts out of my ass
Fear of pressure is driving me to drink
I just can't seem to read the brass




Chronograph work up man


The dance choreography:
Bend over and look at the chono display
Stand up, pull on the costume tail, and yell "High pressure!"
repeat
repeat
repeat
repeat

Enter Hotcore and steps to the microphone:
"Alright chonograph work up man, give it a rest.

Kids you see...Chronographs are excellent tools for telling Velocity, but they don't tell what the Pressure is.

If you see some one measuring pressure with a chono, tell an adult with common sense."

-----

I have wondered for years "who" the first person was that actually thought they could tell Pressure with a chronograph.

I remember the first time I ever saw "Pressure = Velocity"(which it absolutely DOES NOT), was on the old Shooters Board. Created some interesting discussion back then.

You would think the chronograph makers would WARN their users not to make that mistake. Huuumm, maybe they do.

How `bout it Dr. Oehler? Do you all specify in the Owners Manual that it is Impossible to determine Pressure by looking at a Velocity?

OK, thanks for all the warnings about not mixing up "velocity" with "pressure"! I agree that velocity is a result of pressure but the relation is so complicated and depends on so many other fcators that make it impractical to infer pressure from velocity alone.

As a reward fot those who made helpfull comments on my questions, here is a picture of my rifle. Now, back to the loading issues.

I have two kind of brass:

[A] nicle-plated federal brass which has been already shot in my rifle.

[B] new Norma brass.

two types of bullets:

[A] 160 Gr Nosler partition,

[B] 150 gr Swift Scirocco.

two types of primers:

[A] CCI 250

[B] Winchester LR Mag.

and two types of powder:

[A] H 4831

[B] H 1000

Unfortunately, these components don't match exactly with the components used in 7mm Remington Magnum loads in the reloading books I have! So, here is what I am going to do for my first loading experiment:

1) Neck size BOTH brass to make sure that they are uniform.

2) Prime both brass with CCI 250 primers

C) Load the 150 Gr Swift bullets as per Swift manual using 62 Gr of H 4831. (The manual shows 62.8 as minimum load but I will use 62 Gr to be safe)

D) Load 160 Gr Nosler bullets as per Hodgdon 2007 manual using 58 Gr of H4831. The Nosler manual doesn't show a load with H4831 so I am going with Hodgdon. I checked Speer's manual (No 13) and that too shows a load with H4831SC strating at 58Gr for 160 Gr bullets. So, I assume 58Gr of H4831 is safe to start with.

So, I hope this is going to be fine? Please let me know if I am making any mistakes here.

Thanks

quote:

Originally posted by Omid:
... velocity is a result of pressure but the relation is so complicated and depends on so many other fcators that make it impractical to infer pressure from velocity alone.

Hey Omid, You have an Excellent understanding of the situation.

quote:

[A] H 4831

[B] H 1000

I've used a lot of those Powders in my 7mmRemMags and had fine performance/accuracy.

quote:

C) Load the 150 Gr Swift bullets as per Swift manual using 62 Gr of H 4831. (The manual shows 62.8 as minimum load but I will use 62 Gr to be safe)

I like a bit more spread to do my Load Development. With 62.8gr as a MAX, I'd start at about 56-58gr and use the never improved upon Creighton Audette Load Development Method. Doesn't mean you are wrong, but you are not leaving much of a margin "in case" your rifle has a snug chamber/bore. And you may not hit a good Harmonic by only trying the single Load Level.

There are many excellent ways to Develop Loads. You just need to cover a large enough spread so you can see where it is actually Accurate.

But, the best accuracy might be at the 62gr level. You just never know until you Test the Loads.

Since you have a good grasp on how the chronograph works, I'll back out and let these other folks help you with the Load Development. They all have Methods that work.

Best of luck to you.

Omid and HotCore, Are you guys on the same page? Correct me if I am wrong, but one of you is talking 62.8 as MAX and the other as 62.8 as MIN.

Hey Omid, Going below MIN is also a bad idea especially with slow powders. Stick with the published minimum as a starting point.

Hey Steve, Thank you!!! Excellent catch!

That is the reason I don't get into the actual "How much Powder" discussions for a specific Load anymore - misreads on my part.

Hey Omid, Steve is correct that you DO NOT want to go below published "Minimum Loads" with your 7mmRemMag. It has the potential to create a bad thing called Detonation, (Secondary Explosion Effect, Pressure Excursion, KaBoom, etc.)

Thanks again Steve!

quote:

If you exceed the max. listed velocity for a given powder and barrel length, there's a real good chance you have also exceeded the max. pressure!

As Bob Hagel said, "All rifles are individuals. What may be a maximum load in one can be quite mild in another, and vice versa." (It's this "vice-versa" part that catches us!)

What does this mean? It means that when working up a load in your rifle, you have to start low and work up (if you do, in fact, work UP), slowly and carefully, EVEN IF YOU ARE USING THE IDENTICAL COMPONENTS the book specifies. And, getting the same velocity with those components in a barrel of the same length does NOT mean the pressure level is the same, either, although a chronograph is very helpful when working up a load.

Basically, you are in a problem area pressure-wise when bolt opening becomes difficult, primer pockets start opening up, you see marks from the bolt face on your cartridge head, etc. If any of these indications appear, you need to reduce that load at least 5%, and a 10% reduction is even better.

The more you change from Published components, the Closer you should be to the Published Minimum Load. Then you work your way up.

I am a firm believer in a Crono… While I know Pressure = Velocity is not necessarily true… I believe if you have KNOW velocities (tested by the Publisher of the Reloading Book) at Safe Pressures… You can make a correlation. In my mind the key is (as you said) keep the bullet & Powder the same.

That said changing Primers can have a major effect on pressure so be sure to drop to the Min load and work up

Looks like you have the safety angle covered. Accuracy will also be affected if you mix components. Decide which brass you like and primer and stick with it. The same load in different brass may shoot poor groups due to wall thickness and other little manufacturing things. Mixing primers can also affect accuracy.
Enjoy your new hobby.

Omid,

After all this info above - I'm really not sure where to start! But feel the need to add some more info on how I reload hoping it will help you. So, here goes:

I reload for 270, 308, 7.5x55, 7.7x58, 8x57, 9.3x62, 30M1 and several other pistol rounds. I have one or two hunting loads for each rifle a target load for two of them.

First - this discussion on velocity and pressure seems more distracting than helpful but it is at the heart of reloading. You need to know the velocity of your load and you need know the pressure, but short of a ballistics lab you can't measure it!

Here's how I try to infer pressure:

For a hunting load - I'll use the following tools:
1) Excel spreadsheet for notes and a note book for the range.
2) a chrono
3) a mic
4) a magnifying glass

I also will get a box of factory loads with the same bullet I'm interested in reloading. I Always used the same primer for all CR rifles. I'll also use the same brand case for all the subsequent loads I develop for that particular rifle. I'll pick what I believe to be the "best" 3 to 4 powders using 1) reloading books, 2) burning rate charts and 3) references from several friends that reload (and I trust).

I'll start by micing the unfired cases for OAL, dia. at neck, dia. at case just after the neck, the dia. at the pressure ring (3/16" from head) and the dia. at the case body just before the head.

Then I'll reload 8 loads per powder, 2 at 4 different levels. I'll put a number on each round with a marker to indicate amount of powder and put all cases from the same powder in a baggie with a powder label.

I'll shoot all these plus the factory loads across my chrono. Shoot the lighter loads first working up to the top load. Keep good notes and check each primer with the magnifying glass as they are shot. For safety - If any primer goes flat (i.e. the round edge of the primer disappears) or the bolt opens "sticky" stop and don't shoot any of the more heavier loaded round from that powder.

Keep the following notes for each powder/level combination: Temperature, case brand, primer brand, charge wt., chrono velocities. Latter at home I'll then mic the same dimensions for the fired cases.

What you'll have is a way to figure how much additional grains of powder are adding to velocity, a good visual of the progression of the flattening of the primers as the charge is increased, the change of case dimensions from the unfired cases to the fired cases plus the same velocity and dimensions of the factory round.

Hope this helps - Good luck

i recomend getting a nosler reloading manual and use it as your bible. there is so much variation in the manuals and nosler mannual has been right on the money for me. from feet per second to a max powder charge.

i also recomend starting with a middle of the road powder charge and large rifel mag primers for a 7mm rem mag

Thanks everybody for the additional comments.

Hot Core: I appreciate you introducing me to Mr. Audette's method. It seems a reasonable way to find the point of minimum harmonic amplitude. But I have a question: When you change the loads, it changes the bullet's velocity which in turn changes the point of impact. So, the point of impact shows the combined effect of two things: a) bullet velocity b) bbl tip location at the time the bullet exits.

Now, is it right to assume that barrel harmonics are not affected by the load pressure/velocity?


If this is true, then all we need to do to gain accuracy, is to find the right speed of the bullet so that it exits the barrel when the barrel's tip is at the point of minimum movement. And this seems to be what Mr. Audett's method is doing.


To all others: Thank you very much for the tips. I'll consider them when I will load my first batch of ammo (tomorrow)!

quote:

Originally posted by Omid:
..I have a question: When you change the loads, it changes the bullet's velocity which in turn changes the point of impact. So, the point of impact shows the combined effect of two things: a) bullet velocity b) bbl tip location at the time the bullet exits.

Hey Omid, Yes, you are correct on both.

quote:

Now, is it right to assume that barrel harmonics are not affected by the load pressure/velocity?

No, everything in the Load affects the Harmonic. And some external things, like how you hold the rifle needs to be as consistent as possible.

quote:

If this is true, then all we need to do to gain accuracy, is to find the right speed of the bullet so that it exits the barrel when the barrel's tip is at the point of minimum movement. And this seems to be what Mr. Audett's method is doing.

Partially correct. You are correct that we want the Bullet to exit the Muzzle at "the minimum point of movement".

But. let's say you got 2800fps using XXX Powder. If you were to use YYY Powder and also get 2800fps, chances are not good that you would happen to hit a Harmonic Node, but you might. Think back to your Advanced Math Classes, the "dv/dt" is different for each Load combination, with the "area under the curve" being the Pressure as the Bullet moves through the barrel.

Each "Load Combination" is unique in how it produces the Barrel Harmonics. So it is incorrect to make any assumptions about how it will actually perform. The only way to know what hits a good Harmonic Node is to try the Load.

And a particular rifle might not shoot a particular bullet well, when another rifle just like it shoots the same bullet extremely well. That can be very aggravating for a Beginning Reloader, because he may be doing everything correct and still not get the level of accuracy that he wants.
---

Some cartridges have a broader range of Load Development than your 7mmRemMag. With those, you may actually find two Harmonics as the Load Development occurs. But the 7mmRemMag can be very accurate once the correct Load is found.

For some reason my current 7mmRemMag has a particular fondness for 140gr Nosler Partitions. It actually shoots the ones I have better than 140gr Ballistic Tips. I only mention this because the exact opposite is "normally" true. Just have some patience as you move through the Load Development process and pay attention to what the Targets are indicating. And of course, ALWAYS watch for all the various Pressure Indicators.

Best of luck to you.

Omid,

Sorry for the poor spelling in my earlier post - family wanted on comp so I had to type fast. Ran it back thru a spell checked today.

Some details I left out:

For safety, I only have ONE powder open at a time on my bench. I'll finish with it and put it up before loading with another powder. I weigh each powder charge for CF rifles. Also, I will put all charged cases from each powder on a loading block before I put bullet into them - This way I can do a visual on the powder level in each case before putting in the bullet.

When shooting them at the range, I will use one target per powder and not adjust scope in between shots with the same powder. This way I can see the 2 shot groups and how they walk up the target as powder charge is increasing - All my CR rifles do this except the 270 (Don't know why the 270 doesn't?).

I get a little info on accuray by shooting the 2 shot groups but will load more and shoot 5 shot groups to check for final accuray. As you can see, I do a lot of shooting to develop a load, but once established a batch of 50 will last me for several years.

Hi everybody,

Here are some updates on my progress:

I loaded 12 rounds using 150 Gr Swift Scirocco bullets. Each round with 0.5 grain increaments in powder weight (H4831).

I am going to shoot these tommorrow at the range and see how they perform. I'll try to use the method mentioned by Hot Core to find the best load.

A strange observation: It's not possible to seat primers in my NEW norma brass! It seems that the primer hole is too small (?) The primers seat perfectly in my fired federal caes but I have trouble seating primers in the new brass. The primer I am using now is CCI 250.

Any comments on this?

Hey Omid, They really should go in, but a new Case can be quite snug. That is preferable to loose.

Try taking a "Spent Primer" and seating it in the Norma Case. If it will squeeze in, then you probably are Safe to put in the new ones.

Wear Safety Glasses and only have "one" new Primer out if you determine it is OK. When you first try seating a New Primer, only have one out of the box. And make sure it is Seated below the Head of the Case by setting it on something very Flat. If it rocks, it isn't in far enough. But you also do not want to crush the Priming Pellet by over-squashing it. You want to Stop as it touches the bottom of the Primer Pocket.

There is a Feel to it that you will soon recognize as you are doing it. If you get a new one into a Norma case, then go along and seat the rest of them as you normally would.

They are supposed to be a snug fit so you don't get Primer Blow-By which will etch the Bolt Face.

Omid, swapping primers and other components won't always get you in trouble, but it certainly can. I would not do it. If you don't stick with the components in the book, back off on the velocity you hope to attain.

As for pressures, it appears to me that only a strain gauge will give you any reliable clue as to what's going on inside your chamber, and even then a certain discretion is needed in their use. Take care.

Thanks to all you guys, my first reloading experiment went very well. Here are my results from the shooting range:




The above image shows the location of my 12 shots fired at the target at 200 yards. The empreture was around 90 degrees and there was some 10-20 mph cross wind at some points.

Shot number 6 went about 1 inch above the paper target on the card board frame. Shot no 3 was too much to the left of shots 1 and 2 so I didn't connect it by a line. (You can see it's location near shot 9)

And here is the velocity for each shot as measured by my chronograph:




The Swift manual shows a max velocity of 2980 ft/s with 67.7 gr of H4831. But, as you see I got to about 3050 with 66 grains of this powder thanks to the long 25.5" barrel of my rifle.

I did not experince any signs of high presure in any of these loads. So, I am thinking of going one more grain up next time.

So, Hot Core, where are the minimum harmonic points here on this target? I don't have any 3-shot clusters but it seems that shots pairs (1,2), (4 and 5), (8,9) and (10,11) are close to each other. Should I load around these?

Thanks!

Omid,

Nice graph plotting fps vs. powder charge. BTW, my manual lists 65.0gr as max with H4831 and 150gr bullet. But no matter.

What I find unusual is the lack of increased fps between 62.5gr and 65.0gr...all cluster right around 2950fps. Normally you should get about the same increase in fps with every increment of powder. Then, as you approach the maximum for that component combo, you either get no increase or an actual decrease in fps. That's where you stop and back off a little, calling that your max.

Keep plotting your graphs and see if it doesn't hold out. Of course, do not neglect searching for other signs of high pressure as you work up each load. You're on the right track.

quote:

Originally posted by onefunzr2:
...the lack of increased fps between 62.5gr and 65.0gr...all cluster right around 2950fps. Normally you should get about the same increase in fps with every increment of powder. Then, as you approach the maximum for that component combo, you either get no increase or an actual decrease in fps. That's where you stop and back off a little, calling that your max. ...

Hey Omid, The above is an excellent post by Dave. Dosen't matter about any other Pressure Indicators, as long as "One" Pressure Indicator appears, then it is best to call that MAX.

Your Graph points it out clearly and is a great example for everyone interested in Reloading to see. It really drives home what is going on.

With that being the situation, I'd encourage you to focus on Loads around #1, #2 and #3 with #2 as the mid-point. When you look at the Points-Of-Impact(POI), they have "less than" a 1" Vertical spread. The Horizontal spread can be as simple as the cross-wind you experienced.

I would probably Load 3-5 cartridges at each of those levels And shoot all the #1s on one Target, all the #2s on a separate Target and same for the #3 Load. If you know for sure you create a Flier, do not count it. Then Stack those Targets and see if they "tend" to remain around one central point. You are actually performing a Trend Analysis of sorts, seeking a low Variability of Dispersion about a Centroid.

If they seem to be relatively stable, then it is time to select one of those Loads and Fine Tune the Final Load by shooting a Series of Loads when Varying the Seating Depth.
-----

It is also interesting to see the wide Dispersion in POI as the Velocities tend to remain relatively close together between shots 7, 8 9 and 10. Though the Extreme Spread is relatively close, the POIs show they are occurring somewhere between the Apogee and Perigee of a Harmonic Node, which results in the wide Vertical Spread. This is another reason why focusing only on chronograph readings can be misleading.
-----

I would also re-shoot Loads for #4, #5 and #6 as I did for 1, 2, and 3. But it is on the Edge of what appears to be the SAFE MAX for your specific rifle and components. If you try this, segregate those cases and make sure you do not experience loose primer pockets. If you get acceptable groups at that level and if the primer pockets remain snug for 8-10 shots per case, then I'd go with it as the Final Load.
-----

Actually, I should have asked "you" where you would have focused on the next series.

Try to shoot at sunrise or sunset because the wind typically calms for about 25-40min.

And shoot at one "corner" of either Square. Just snug the Crosshair right up against it. That way you are only having to maintain your focus on two lines instead of four quadrants.

DO NOT over-heat your barrel. Do not allow it to get HOT to the touch.

Your final results are headed toward low Variability, which results in Consistent accuracy. H1000 "may" be more acurate with less variability, or it could have a wider dispersion. Only way to know is to try it at some point.

You are doing great!

quote:

Originally posted by Hot Core:

quote:

Originally posted by onefunzr2:
...the lack of increased fps between 62.5gr and 65.0gr...all cluster right around 2950fps. Normally you should get about the same increase in fps with every increment of powder. Then, as you approach the maximum for that component combo, you either get no increase or an actual decrease in fps. That's where you stop and back off a little, calling that your max. ...

Hey Omid, The above is an excellent post by Dave. Dosen't matter about any other Pressure Indicators, as long as "One" Pressure Indicator appears, then it is best to call that MAX.

Your Graph points it out clearly and is a great example for everyone interested in Reloading to see. It really drives home what is going on.

Thank you for the prompt answer! So you are saying that the lack of increase in bullet velocity after Shot # 5 is actually due to high chamber pressure? I agree that it is unusual but can't it be just due to measurement inaccuracy? Or barrel heating or some other factor? After all, the velocity figures are only based on one shot which is far from enough to establish a reliable value for the velocity.

I checked the primers for flatness and also the head of the cases for signs of pressure (edjector mark etc.) but there was none. Also, the bolt opened normally after each shot. So, I assumed that the presure is under control.

anyway, I agree that the best practice is to stay below load #6 for now. I'll do a set of reloads for next week but this time I will organize them as groups of 5 shots. Each group will have the same charge. This way, I can test the velocity and accuarcy much more reliably.

Thanks again.

quote:

Originally posted by Omid:
... So you are saying that the lack of increase in bullet velocity after Shot # 5 is actually due to high chamber pressure? I agree that it is unusual but can't it be just due to measurement inaccuracy? Or barrel heating or some other factor? After all, the velocity figures are only based on one shot which is far from enough to establish a reliable value for the velocity. ...

Hey Omid, There "might or might not be" Higher Pressure at that point. If you were measuring CHE & PRE you would know for sure how those Cartridges reacted. But as I will get into, what you saw is an Indicator that is best to avoid.

It simply indicates that something "changed" from what was expected. And that is enough reason in itself to STOP and determine what is different. Probably not due to measurement inaccuracy or barrel heat. That is a "guess" based on many years of seeing Pressure Variations while measuring CHE & PRE.

If the Powder is Fast enough that it won't fill the Case before a SAFE MAX is reached, the Pressure usually becomes Erratic at some point past a SAFE MAX Load. One "Indicator" is the relatively Flat Line velocity - no Velocity gain for an increase in Powder. There are a good number of Theories about what is going on at this point, and good arguments can be made for a few of them.

I tend to believe the "Extended Powder Column Theory", which says;
1. The Powder is Ignited by the Primer and Pressure begins to build.
2. As the load of Powder is reached where the relatively Flat Line(or unexpected variation begins), it is believed the burning has not yet ignited all of the Powder, but the Pressure has risen to the point where it will begin moving the Bullet(and some non-ignited Powder) forward into the Bore.
3. This Reduces the Pressure a bit because there is effectively more Chamber Volume.
4. The Burning then overtakes the non-burning Powder which has moved ahead slightly, consumes it and tries to Raise the Pressure.
5. It is considered Dangerous at that point due to the instability and inconsistent Burning. You just don't know for sure "How" it will react, due to a lot of variables.
------

I rarely get into this discussion, because a lot of folks recommend Faster Burning Powders rather than the Slow Burning Powders for a specific cartridge. Some of them know what they are doing and it works very well for them. The problem is that many of the people they recommend Fast Powder Loads to typically do not understand, how going a bit beyond what was recommended "has the potential" to create Pressure Extremes.

I just saw three threads on the Board asking for Hot Loads. Often these are folks with a modicum of Reloading Experience and beleive it is possible for someone to "give them" a Hot Load for their rifle, which is accurate and SAFE. That is BAD WRONG!

If you scan those threads, you will notice the more Experienced Reloaders took the time to WARN them that they ALWAYS need to develop a Load specific to their rifle, work up from below, and just because a particular Load works well in one persons rifle doesn't mean it will work well in their rifle. Worst of all it might not be SAFE.

That same ignorance about Reloading got Rookie Green(green788) laughed off this Board with his Optimum Charge Weight(OCW) fiasco.
-----

Kind of got would up there. It is just normal at this time of the year to see people asking for Hot Loads. They just don't know how wrong that is. Thinking that there are "short-cuts" in Reloading is due to a lack of understanding and can be dangerous.

OK, here are some new results from my second reloading experiment:




The red cureve is the old result (one shot per data point) and the blue curve is the new data (average velocity of three shots).

And here is the result of some experiments with 160 grain Nosler Partition bullets. In this plot, each data point shows the average velocity for three shots:



It's interesting that I have got consistently higher velocities (about 50 ft/s) in the second round. I don't know why; may be its due to wind or difference in temprature or air pressure? Or may be beacuse my brass were already fired twice and now they have got a bit thiner?

Anyhow, I just thought I would share the results with you guys.

For the next round of reloading, I am going to try new Norma brass and Win LR Magnum primers to see how things change.

* * *

A minor question: My WLR Mag primers all show some greenish color on the side were the anvil is. It looks like a sign of rusting metal. Is this OK or I should be concerened?

Thanks

Hot Core,
I've got to say that the two links you posted with your explanations of the Creighton Audette Method and measuring CHE and PRE had some of the most informative and useful content I've seen here since I started visiting this site. They're well written and easily understood.

Many thanks for your contributions.

quote:

Originally posted by Omid:
...My WLR Mag primers all show some greenish color on the side were the anvil is. It looks like a sign of rusting metal. Is this OK or I should be concerened? ...

Hey Omid, Take a 100 pack of them to a local Gun Shop and ask someone who has Reloading Experience what you are seeing. I'm "guessing" it is just the color of the Priming Pellet Mix, but "guesses" are not what you need.
-----

Hey Nate, You are welcome.

Try them out and see how you like them. And if you have a bit of time after that, post your results for everyone. If you find something "better" than Mr. Audette's Method, be sure to let me know, cause I want to try it too.

The CHE & PRE info seems to generate a good bit of debate about how accurate it is. Over the years, I've normally found that the people deriding those methods are doing something a bit different than what you see in that post - like how to "Accurately Measure" the PRE value, or perhaps they are Neck Sizing during the Load Development.

Single measurements are not perfect due to material variations in the Cases and Components. A person needs to take enough Samples to make the data worthwhile. As a person gets comfortable taking the measurements, the reasons for the minor Tricks to do it become self evident.

Lots of experienced folks on this site do not use either of those Methods and get along fine. So, there are a lot of excellent Methods out there - just none as good as these.

Good Hunting and clean 1-shot Kills.

I plan on trying the Audette method very soon. If I can get to a range tomorrow I'll give it a shot (so to speak). The longest range I can find is 200 yds so hopefully that works. I can't try the CHE and PRE yet since I don't have the proper measuring tools. My blade calipers go to .0005. Maybe someday.

Take care.

Hey Nate, I've heard you all are getting to use some Revolver Cartridges this year to Kill Deer. If you are Developing Loads for them, then 50yds, 75yds or 100yds will do just fine. I'm thinking about cartridges like the 357Mag, 41Mag, 44Mag or 454CAS.

There is an additional group comprised of cartridges like the 30-30, 35Rem, 444MAR, 45-70, etc., where 100yds is plenty of distance to do the Load Development. With the shorter range cartridges, Mr. Audette's Method can be a bit more than is really necessary. Just staying at or below Loads shown in a few Manuals while watching for other Pressure Indicators, will do just fine and is a lot less work.
-----

Most of the on-line reloading supply shops have 0.0001" capable Micrometers at very reasonable prices. The next time you place an order with one of them, you may want to consider seeing what they have. I beleive Widners used to have them for less than $25. Not sure how much they are today. By the way, the Electronic LED Display models will drive you crazy if you do not use them every day. They tend to "shift between measureemnt values" in unskilled hands. Here is one situation where the Highest Cost is not always the best tool for the casual user.

Best of luck to you. Good luck with the weather tomorrow.