Hello the Campfire:
Did anyone read the article in "Reloader Mag.' on the "Rules of Reloading", concerning the mathmatical rules regarding changes in case capacity, bullet weight and caliber? He calls it the"Rule of Fours" If the figures hold up, it could be a useful tool in deciding what to use when. The bottom line I got from the article was that small changes in size, capacity, or weight cause enough of a diferance to worry about, such as in the improved calibers. Ido think that a easier formula with less steps could be derived from his information.
What does the camp think?
I think that I did spot a math mistake in one of his calculations concerning case capacity, but I will have to work it out myself to be sure. This from an old man who cant keep his check book straight.
Talley Ho!
Judge Sharpe

Mea Cupa-
I put the wrong magazine in my post. It was Handloader.
Sorry. I think this is a good artical if anyone is interested.
JUdge Sharpe

JS. No less safe that letting this 68 year old old goat run around in the woods with a high powered rifle. Hell, I'm just glad I can still do it.
Paul B.

My 2 cents,fwiw, etc. The man knows what he is talking about. Read him for several years now and all he had in that article has been discussed in depth over time. In this age of BS, he is a no BS guy. I am like a lot of other guys, tired of the rags, but he holds my interest.

He has written these "rules" separately in articals over the years and they always seem to hold true or very close. I hope they're true, I used his formulas to work up loads for my wildcat round based on the closest round to it and everything seems fine by the old judgement standards. One thing I like about John is he is very realistic in his loading. He doesn't try to sell some new idea as the end all solution based on manufacturers claims, he tests them for real. He is also one of the only writers that agrees you really do need a chronograph to reload safe max loads based on preasure test data in the books. I've always been the type to say that there are no free lunches in life and his writing show the same principals.

quote:

Originally posted by NBHunter:
... He is also one of the only writers that agrees you really do need a chronograph to reload safe max loads based on preasure test data in the books. ...

Hey NBHunter, I've got no idea who you all are talking about because I've not read the article. However, if the writer believes there is some "valid" correlation between a Velocity taken from a Chronograph and "Pressure", then he has a lot to learn.

Too many Variables from Lot to Lot in the cases, primers, powders and bullets. As well as the Manufacturing Tolerances(acceptable variation) in the Chamber and Bore dimensions, plus the Surface Finish from Bore to Bore.

There is a reason he is, "one of the only writers", to believe that - he is seriously mistaken.

While there are variables - low velocity may be accompanied by high pressure due to primer differences, etc. - one does need higher pressure to develop higher velocities.

Hot Core, your saying that John Barsness "has a lot to learn" about pressure is one of the most "pot calling the kettle black," head-shaking moments it's been my pleasure to witness. No one with a access to pressure testing equipment, or indeed a modicum of knowledge of statistics, credits any longer the pulpit you preach about "Case Head Expansion," etc.

Please continue to post. You certainly have some great ideas about minimalist handloading that I would miss if they ended, but also, please know that your descriptions of pressure events are the very first things I skip. There is enough fiction in these sites as it is for anyone to add more.

Jaywalker

Hot Core, he is very balanced in his approach. Read some John Barsness reloading articles. He does put it ALL together.

quote:

He does put it ALL together.

True. If you doubt his statements, read on. The proof will be there.

"low velocity may be accompanied by high pressure due to primer differences"

Yes, he's even covered that one too. Notice how he only uses CCI primers now. John is a true Myth Buster in the reloading world and a lot of people don't like that.

quote:

Originally posted by Jaywalker:
...Please continue to post. ...

Hey Jaywalker, I certainly appreciate your desire for me to continue posting.

How about this? Please explain to me "how you think (or believe)" a person can obtain Pressure from the Velocity provided by a Chronograph.

Always willing to learn something new.

Hot Core,

I think what Jaywalker was saying is something like this:

Chamber pressure is what pushes the bullet down the barrel. The higher the velocity of the bullet measured on the chrony, the higher the relative pressure pushing that bullet. Out of the same rifle, with the same type of bullet/brass/primer/powder variety higher velocities are the result of higher pressures.

Practical application: IF your velocity is significantly higher than book max for a particular bullet and powder combination, THEN that is a pretty darn good sign that you are running high chamber pressures that may or may not be otherwise apparent from reading the tea leaves on your brass and primers.

I don't have a formula to translate a velocity to a particular pressure level. Probably can't be done. But as a diagnostic tool, consistent chrony readings indicate consistent pressures. If they are consistent, within reach of book max velocities, and you see no other signs of pressure in the brass and primer voodoo. You have a safe load.

If Barsness is mixing the Kool Aid ... I'm drinking it.

Just to clear this up some, I'm not saying that if you pack Unique into a .270 until you reach 3,000 fps your load is safe. It means that if your tested data says that X grs. of IMR4831 in Win brass with Win LR primers and a 130gr partition is say 60,000 psi at 3,000fps and you reach 3,000 fps one grain less in an equal length barrel than your most likely in the 60,000psi range and you should not keep adding powder because the bolt doesn't lift hard yet.

Or like my favorate quote about life......."There are no free lunches"

HOLY CRAP.....HERE WE GO AGAIN. I don't think Hotcore is a bad guy. It's real possible he has a severe case of A.D.D. like I do but when he chimes in the whole thread will go down a path of him chasing ideas past people and defending himself from there on out.

When you read his first post, without even knowing what articles are being talked about....reading them.....respecting the many years of service and experience of the writer.....he chimes in with an idea and says the "writer of the article may have alot to learn".

The more you respond the more you will be quoted and the more Hotcore will go on and on.

Come on Hotcore....you are a good guy with some good reloading experience. Just simmer down and be "IN THE MIX" once in a while instead of "CAUSING THE MIX!!"

Barsness' Handloader article on the "rules of thumb" he has devised is a pretty decent article, as is most of his writing. His "rules" don't miss it far, however I didn't appreciate the way he cherry-picked data from reloading manuals to validate his observations. He, of all people, should know that the variables in test equipment and the standards of one group of technicians used in one manual versus the different standards of another group introduce so many variables as to make such cherry-picked data meaningless. He could just as easily have used the same manuals to cherry-pick data that undermined rather than supported his hypotheses.

Nonetheless, he ain't far off; it's just that his shortcut in providing evidence to support his observations/theories is less than compelling.

Damn- I did not mean to cause a fight. I just meant that I thought it was a good artical and wondered what others thought about it.

Judge Sharpe

Hot Core. I use a chronograph as one way of determining pressure with a particular powder for a particular cartridge.
As an example, let's say we're loading for a .270 with a 130 gr. bullet using powder "X". Average max load in say six different manuals is 60 gr. for 3000 FPS. Starting load is maybe 55.0 gr. So we load up a pressure series running each load over the Chrony and measuring case head expansion. I'll ignore the case head exxpansion numbers for brevity and stick with just the Chrony results.
Any smokeless powder has a usable pressure region where it is efficient. Go below that region or above it, and there is where the problems come from. Velocity becomes erratic and possibly SEE rears it's ugly head.
So, using the above powder "X" and starting at 55.0 gr. the pressure/velocity series might go like this.
55.0 gr. 2800 FPS
56.0 gr. 2850 FPS
57.0 gr. 2910 FPS
58.0 gr. 2970 FPS
59.0 gr. 3050 FPS
60.0 gr. 2940 FPS (HUH!)
Based on the those figures two things become apparent.
One: as charges are increased, velocity gain is basically linear.
Two: Once you go past the working pressure curve of the specific powder, velocity becomes erratic. It can either have a radically larger increase or lowering of the velocity.
Looking at my hypothetical numbers the 59.0 gr. load may or may not be excessive. If all the book data was worked up in 22" barrels and my rifle has a 24" barrel, it might be just fine. If my rifle also had a 22" barrel, I'd drop back to either 58.0 or 58.5 gr. and call it maximum for my rifle based on the velocity.
Do I say it is a foolproof system? NO, but I've found it to be just another reasonable guideline when working up loads for my rifles. While it may not be perfect, it does keep me from going off the deep end when working up loads.
There is a book that I feel evry person who wants to handload cartridges should read before ever starting. Unfortunately, it is long out of print and used copie are a bit pricey. It's long, somewhat dull in places and is a heavy weight book called PRINCIPLES AND PRACTICE OF LOADING AMMUNITION by Earl Naramore. The first two thirds or a bit more concerns commercial manufacture of loading ammo which is somewhat interesting and the rest pertains to the handloader. IIRC, it's copyright is 1954. Well worth reading It's some of Mr. naramore's experiments that led to the case head measuring methods we use today.
Paul B.

quote:

Originally posted by Hot Core(for Jaywalker):
How about this? Please explain to me "how you think (or believe)" a person can obtain Pressure from the Velocity provided by a Chronograph.

And the response from our Chronograph expert Jaywalker:

quote:

Originally posted by Jaywalker:
(...Nada, Zilch, Nothing...)

Hey Jaywalker, I certainly appreciate your help in explaining how you Chronograph Experts use them.
---

Our old buddy "Hammer" and I had been discussing a Bore Cleaning Test and he brought up some data Mr. Barsness had performed in this Thread. And my response was:

quote:

I used to read a good bit of Barsness and decided that he reports what he sees, or believes he sees. I do not think he intentionally mis-leads anyone.

That said, I disagree with him on a good number of things. I suspect it is simply because our experience has been different.

Hey Paul, Excellent, well structured post!

I hope you don't mind if I highlight a few of the statements and then ask you a question at the end.

quote:

Originally posted by Paul B:
Hot Core. I use a chronograph as one way of determining pressure with a particular powder for a particular cartridge.
As an example, let's say we're loading for a .270 with a 130 gr. bullet using powder "X". Average max load in say six different manuals is 60 gr. for 3000 FPS. Starting load is maybe 55.0 gr. So we load up a pressure series running each load over the Chrony and measuring case head expansion. I'll ignore the case head exxpansion numbers for brevity and stick with just the Chrony results.
Any smokeless powder has a usable pressure region where it is efficient. Go below that region or above it, and there is where the problems come from. Velocity becomes erratic and possibly SEE rears it's ugly head.
So, using the above powder "X" and starting at 55.0 gr. the pressure/velocity series might go like this.
55.0 gr. 2800 FPS
56.0 gr. 2850 FPS
57.0 gr. 2910 FPS
58.0 gr. 2970 FPS
59.0 gr. 3050 FPS
60.0 gr. 2940 FPS (HUH!)
Based on the those figures two things become apparent.
One: as charges are increased, velocity gain is basically linear.
Two: Once you go past the working pressure curve of the specific powder, velocity becomes erratic. It can either have a radically larger increase or lowering of the velocity.
Looking at my hypothetical numbers the 59.0 gr. load may or may not be excessive. If all the book data was worked up in 22" barrels and my rifle has a 24" barrel, it might be just fine. If my rifle also had a 22" barrel, I'd drop back to either 58.0 or 58.5 gr. and call it maximum for my rifle based on the velocity.
Do I say it is a foolproof system? NO, but I've found it to be just another reasonable guideline when working up loads for my rifles. While it may not be perfect, it does keep me from going off the deep end when working up loads....

Hey Paul, What is the Pressure?

Not trying to argue with you as Kraky suggested, I'll let your words make the point for me.

If the hypothetical Load you described won't provide the "Pressure", I've no problem with you listing a real Load with the resulting Velocity and the Pressure.

quote:

Originally posted by NBHunter:
Just to clear this up some, I'm not saying that if you pack Unique into a .270 until you reach 3,000 fps your load is safe. It means that if your tested data says that X grs. of IMR4831 in Win brass with Win LR primers and a 130gr partition is say 60,000 psi at 3,000fps and you reach 3,000 fps one grain less in an equal length barrel than your most likely in the 60,000psi range and you should not keep adding powder because the bolt doesn't lift hard yet.

Or like my favorate quote about life......."There are no free lunches"

Hey NBHunter, Also a nice post. Would you expound on the comment, "most likely in the 60,000psi range" for the Beginning Reloaders?

Hey Gaviidae_Esq., First off, Welcome Aboard! Always good to have another Reloader join in. Sure is nice of you to help out Jaywalker with some kind of response.

quote:

Originally posted by Gaviidae_Esq.:
Chamber pressure is what pushes the bullet down the barrel. The higher the velocity of the bullet measured on the chrony, the higher the relative pressure pushing that bullet. Out of the same rifle, with the same type of bullet/brass/primer/powder variety higher velocities are the result of higher pressures.

It appears in "Paul B's" example that your above statement is not always true (and I agree). Do you disagree with Paul's example?

quote:

Practical application: IF your velocity is significantly higher than book max for a particular bullet and powder combination, THEN that is a pretty darn good sign that you are running high chamber pressures that may or may not be otherwise apparent from reading the tea leaves on your brass and primers.

In regard to "reading the Tea Leaves", could you clarify what you are talking about here for the Beginning Reloaders? And it would sure help us understand your perspective if you let us know how much experience you have with what ever you mean by "reading the Tea Leaves".

quote:

I don't have a formula to translate a velocity to a particular pressure level. Probably can't be done.

I do believe you are agreeing with what I said in my initial post.

quote:

But as a diagnostic tool, consistent chrony readings indicate consistent pressures. If they are consistent, within reach of book max velocities, and you see no other signs of pressure in the brass and primer voodoo. You have a safe load.

What are these "other signs of Pressure" and "Voodoo" you seem to be relying on to make sure you are SAFE?

quote:

Originally posted by JudgeSharpe:
I did not mean to cause a fight.

Hey JudgeSharpe, What fight?

quote:

Is it safe to let for a 56 year old man run around in the woods unsupervised with a high powered rifle?

It "might" depend on if he really thinks a person can somehow deduce Pressure from Velocity.

Hot core admits that he didn't read the article, then attacks it. Certainly the velocity is a function of the integral of the pressure. Certainly if you are using a normal powder and your "super load" gives high velocity then the pressure is high.
The availability of strain gage pressure equipment has given us yet another generation of "ballistic experts". Remember the "muzzle" pressure pulse. Nobody took the time to remember that the strain was measured at the breech.Anyway the "problem' seems to have cured itself.
Good Luck!

quote:

Originally posted by hawkins:
Hot core admits that he didn't read the article, then attacks it...

Hey Hawkins, Looks like your "string" of Wrong AGAIN! continues.

Nope, didn't attack the "article" at all. Did comment about the (unknown to me) "Author" of the article based on what the other posters said about the article and Author.

quote:

Originally posted by Hot Core:
...if the writer believes there is some "valid" correlation between a Velocity taken from a Chronograph and "Pressure", then he has a lot to learn.

....

There is a reason he is, "one of the only writers", to believe that - he is seriously mistaken.

Hang in there hawkins, maybe your old buddy howl can help you understand all of this.
---

Don't you just hate it when you go to attack someone and make a complete clinton of yourself?

Sure glad I've never done that!!!

I guess I didn't understand what "Didn't read the article", and he is "seriously mistaken"
was intended to convey.
Sorryboutthat!

Judge, was a good article and I liked it because I've been reading Barsness for quite a while now. He puts thiongs together well. This must be the week everybody ran out of their meds(see other forums) or what moon phase is it?