So I know that the best reloads are the most consistant ones. Consistant meaning uniform all the way around in case prep. Also meaning muzzle velocity being as little deviation as possible.
To get to muzzle velocity we can change primers and powders and even bullets and bullet weights.
My question is; If I find a load with a consitant velocity and it is grouping well, can I change seating depth to get a better group without effecting velocity?
The reason I ask this question is I can sit here at the house and test for consistantcy in velocity rapidly but, I have to load up a bunch of stuff and travel to get to a range where I can sit and get a target out at 200yards to get an idea of group size.
(I prefer 200 over 100 because it show better or worse progress alot easier)

Thank folks!!!

Yes, you can change seating depth without having a noticable effect on velocity. Generally speaking, best accuracy occurs with the bullet is seated "closer" to the lands rather than deeper in the case.

According to the Reasearch and Development Dept. of the Nosler Bullet co. they state that no appericable accuracy is created! Only changes in pressures and it turn velocities!Coarse some here will dispute this as they have more info at there disposal than Nosler. If you question there findings,contact them. vangunsmith

quote:

Originally posted by van:
According to the Reasearch and Development Dept. of the Nosler Bullet co. they state that no appericable accuracy is created! Only changes in pressures and it turn velocities!Coarse some here will dispute this as they have more info at there disposal than Nosler.

Hey Van, Would you explain "Why" changing the Pressure or the Velocity would have no effect on the Barrel Harmonic?

Best of luck to you.

quote:

Originally posted by smedley:

My question is; If I find a load with a consitant velocity and it is grouping well, can I change seating depth to get a better group without effecting velocity?

IME, no. A small amount of seating depth may be undetectable within the normal variation of velocity, but a large change like .1" or more will affect the pressures in your chamber and thus the velocities.

I haven't done any tests on this. There are a couple of guns I load for that have to be seated very deep because of magazine depth and they both have slower velocities with the same bullets and amount of powder as used in other guns in that caliber.

Unfortunately, there is no way we can sit at the bench and program any sort of load change to accomplish a particular end result. Changes must be made as an experimental test and the results checked with firing.

Sorry but ... them's the conditions that prevail!

quote:

Originally posted by smedley:
So I know that the best reloads are the most consistant ones. Consistant meaning uniform all the way around in case prep. Also meaning muzzle velocity being as little deviation as possible.

I'm not at all sure this is correct.....it just seems so.

Truth is that accuracy is finding a load that fits your barrel/gun and has little to do with uniformity.

If the bullet isn't in tune with the barrel all the uniformity in the world won't get you accuracy!

quote:

My question is; If I find a load and it is grouping well, can I change seating depth to get a better group without effecting velocity?
The reason I ask this question is I can sit here at the house and test for consistantcy in velocity rapidly but, I have to load up a bunch of stuff and travel to get to a range where I can sit and get a target out at 200yards to get an idea of group size.

Thank folks!!!

Seating depth has little effect on velocity unless there is a radical change.....such as free boring a chamber...

That said you have to shoot them to know that accuracy improved! That's the fun part!

BTW....I post my own experience and could give a rat's ass what Nosler says!

Woods,

Do you get slower velocities from the deeply seated bullets because you use a faster powder in these rifles due to case volume loss taken up by the deeper bullet?

quote:

Originally posted by Buliwyf:
Woods,

Do you get slower velocities from the deeply seated bullets because you use a faster powder in these rifles due to case volume loss taken up by the deeper bullet?

No. These were both 300 win mags where case volume was not critical. I used the same powder. One was a Browning with a detachable mag and the other was a Savage.

My results were not conclusive as I only observed it on these 2 occasions. A better test would be to load identical loads in one rifle and seat one bullet .15" deeper and see what happens, but I haven't done that.

Ok. Thanks.

I know you will increase pressure seating the bullet into the lands of course, because this reduces chamber volume. I was trying to think why seating the bullet deeper happened to give lower velocity. As you say, different test needed.

Thanx again.

I use a Lee hand press at the range. I seat the bullets pretty long at home, then progressively seat them shorter to see if cartridge overall length makes a difference in accuracy.

quote:

Originally posted by Hot Core:

quote:

Originally posted by van:
According to the Reasearch and Development Dept. of the Nosler Bullet co. they state that no appericable accuracy is created! Only changes in pressures and it turn velocities!Coarse some here will dispute this as they have more info at there disposal than Nosler.

Hey Van, Would you explain "Why" I changing the Pressure or the Velocity would have no effect on the Barrel Harmonic?

Best of luck to you.

I NEVER said it wouldn,t. I just said what Nosler company said!

quote:

Originally posted by van:
...Coarse some here will dispute this as they have more info at there disposal than Nosler.

Hey van, Perhaps I misunderstood that portion of your post. I got the impression you agreed with what you said Nosler "claims". I also got the impression you believe if we disagree with that "claim" we must be incorrect.

Other than posting a "claim" by Nosler where the "info" is obviously Full-of-Beans, is there a chance that you may have misunderstood what was being claimed? What was the point you were trying to make? Not trying to argue with you, I just don't understand what you were trying to get across.

Nosler sure makes some outstanding Bullets that I enjoy using. But I sure don't understand why anyone that has an understanding of Barrel Harmonics would "claim" that a change in Pressure and Velocity would have no effect on accuracy.

Best of luck to you.

Okay, thanks folks!!!!

That is what I wanted to know for the most part.

Vapodog, I understand what you are saying about the bullet being the right "flavor" for the barrel. That of course would come into play.

What I was hoping for is just what you all posted: little changes to seating depth will make little difference to velocity. Trying to tune into the harmonics for my rifles!

If one wants Quickload to predict the change in velocity and pressure that happens when the bullet is touching the lands or is jammed in, then the start pressure must be changed.

Accuracy improves for me in most cartridges with the bullet jammed into the lands. 45 Colt in a Win 94 is the exception.

As Bart Bobbit points out, the penalty for the extra accuracy is increase in pressure and possibly a real mess if you don't shoot, and try to extract. Having powder spilled all over the inside of the action is unpleasant at the range, but the stuck bullet can be problematic when hunting without a cleaning rod.

Smedley: I am a little confused and I have a difference of opinion, for you to ponder as well!
First I am confused - are you saying you have a chronograph at YOUR HOUSE and you can shoot loads through it to find "consistEnt" velocities?
But to actually see if your "consistEnt" velocities at home are REALY accurate you must travel to your range and do the 200 yard accuracy check?
I hope I explained my confusion well enough for you to straighten me out.

Now as to my difference of opinion (experience) with you on the 200 yard versus "other" ranges to check a Rifles (or a load in a Rifles) accuracy.
I contend that checking a load or a Rifle is BETTER done at 100 yards!
During my formative years (for 3 decades!) I shot (life member) at the Seattle Police Athletic Associations 100 and 200 yard Rifle range there in south Seattle.
During the months of January, February and early March the air at this range was often ABSOLUTELY without movement!
Dead calm!
This range was at an elevation of about 30 feet above sea level and calmness was the rule on those months, mornings! Many of these days were a bit or a lot foggy and believe me there were NO heat wave distortions at all - during those times!
I relished each year, these still times and shot many dozens of Rifles for accuracy testing during these months and years.
I won't go into ALL the reasons I quit testing (for accuracy!) at 200 yards! To make a long story short it was a waste (I proved this to myself many times) to test Rifles and loads at 200 yards.
I quit doing 200 yard testing and feel that 200 yard shooting is LESS likely to prove a Rifle or a loads accuracy than 100 yard shooting is!
I now live in SW Montana and shoot at a range where I am a member that has 25, 50, 100, 200, 300 and 1,000 yard butts along with the availability to set up targets at ANY yardage in between 25 and 1,000 yards.
I use the 100 yard range exclusively for load testing and Rifle sight in verifications. I often shoot at the extended distances though to verify my trajectories!
I also often shoot at another range that is privately owned and only I and the owner shoot here. He has a shooting shack (wide and 12' high) and it is built in a canal with 7 foot high sides - so in effect I am shooting down half a tunnel!
This range is 100 yards long!
Seldom is the wind able to affect my groupings.
I could NOT be happier with a range, unless if maybe it were in a warehouse!
There is also a 600 yard distance for shooting at this private ranch but I seldom avail myself of it.
Without going into all the reasons why I quit the 200 yard range load, and Rifle testing is it tests the shooter more than the load or the Rifle!
Now if on those rare occassions where someone may have a question of bullet stability at longer ranges that, in my opinion and experience, is a valid reason for a longer range test. But 100 yards is my preffered distance to check for accuracy as opposed to testing marksmanship and condition changes at the longer ranges.
Love to hear your comments in this regard.
Hold into the wind
VarmintGuy

If there is any wind at all, I switch from the 100 yard to the 50 yard target.

I put one staple in the top center of the 8.5"x11" paper target, and if it bends at all with wind, I wait, even at 50y.

quote:

Originally posted by tnekkcc:
...I put one staple in the top center of the 8.5"x11" paper target, and if it bends at all with wind, I wait, even at 50y.

Hey tnekkcc, If the wind is strong enough to bend the staple - I'd wait too.

Some time ago there was a poster here and on other boards, Stan Watson, whom went by the name of "OKShooter". He did a lot of testing with a couple of 30-06 rifles, a M700 BDL-DM 22" bbl a M70 24" bbl, and an Oehler 43 PBL.

(That`s a strain system such as HC abhores mention of )

He published a report of his findings in a notebook.

Stan did a run on seating depth vs pressure and velocity useing the M70 with a load consisting of a 180 gr Hornady SP over 60 gr H4831sc, R-P case and 9 1/2 primers. He reported the following;

distance of ogive from lands - vel - pressure
0.164" - 2608 fps - 50,600 psi
0.059" - 2620 fps - 51,300 psi
0.039" - 2621 fps - 51,200 psi
0.019" - 2624 fps - 52,100 psi
-0.001" - 2622 fps - 52,100 psi = touching lands
-0.021" - 2633 fps - 53,400 psi = jammed in lands

Stan claimed nothing other then this was the result of 1 test with 1 set of components and could possibly change with another load.

VG,
Sorry it took so long to get back to ya. I went "song dog" whacking this weekend and didn't look back to this post.
For the most part you are correct. I can sit here at the house and do powder/primer combo's here and squeeze off rounds to get a consitent velocity or at least the spread down.
I 'spose I should back up a little bit to give you some more info about what I am dealing with.
I live in the NW above Seattle in a very heavy vegitative enviroment. Lots of Black berries and Salmon berries. Oh and in between all that, lots of Evergreen trees. About the longest "flat" shot I can get here at my place is 40-50 yards, if that!
Setting up the crony here is not a problem. At the range you CANNOT step past the firing line even if you are the only one there. Also you CANNOT go get your targets and that is why I prefer the 200 yard targets. It is alot easier, for me, to look through the spotting scope and see the cluster at 200 and see if it is getting tighter or opening up.


PS we'll get along alot better if you do not point out to the whole board and me my spelling errors.