I have a new article on Brinell hardness....

[Bass Ackward]

After all the fullin around I have done, I'm all over the map. Probably more ignorant than when I began this journey. Rifles for me tend to be logical and fairly predictible. Handguns there is no logic or pattern.

I use lino for low pressure 38 Special and 45 sometimes and 20-1 sometimes for high in different cartridges like 357 an 44. And thank God this fits my style. Allot of folks know that I mold all winter, but often my interests change that year and I run out of something and have to get by with something else. Some of my most biggest surprises are loads that are "worked up" for other guns and I accidentally grab the wrong shells when I went out.

After all the education and logical deduction, especially when you have to many guns to try every combo, it is my Forrest Gump style that gets me through at times.

[felix]

Don' feel like the Lone Ranger. ... felix

[Harry O]

prgallo: I also did some testing before deciding that this worked for me. I didn't just pull this out of my a$$.

It was in a rifle, a 1910 Mannlicher-Schoenauer in 9.5x57 MS caliber. I had to do this because the ONLY bullet that would feed properly from the MS magazine was a Lyman 375167. That is a PLAIN BASE bullet, with no provisions for a gas check. I knew that I would be limited on speed, but I did not know how much.

The first group I cast up was about Bhn 15. I loaded up a bunch from 42gr to 48gr of IMR4064. The groups were poor from the start. I went back and loaded up some more from 32gr to 42gr. Groups were fair at the start, but the accuracy abruptly took a nosedive shortly after I started and the barrel started leading a couple of hundred fps above that.

I heat treated the same batch of bullets and got them up to Bhn 20-22. Loaded them up again and tried them at the range. By increasing the hardness by nearly 50%, I only got the velocities up about 200fps. Interestingly, the leading started showing up AFTER the accuracy took a nosedive again, not before or at the same time.

I later went back with the loads and velocities I got from these tests and figured what the pressure was (with a Powley Computer). The pressures where the accuracy took a nosedive were very close to what the Bhn x 1422 number predicted.

I am shooting a 375167 right now that is cast and heat treated to Bhn 37-39. I can go to full loads with that one. If I had started out with that, it would have saved me a lot of time and effort.

[357shooter]

prgallo: I also did some testing before deciding that this worked for me. I didn't just pull this out of my a$$.

It was in a rifle, a 1910 Mannlicher-Schoenauer in 9.5x57 MS caliber. I had to do this because the ONLY bullet that would feed properly from the MS magazine was a Lyman 375167. That is a PLAIN BASE bullet, with no provisions for a gas check. I knew that I would be limited on speed, but I did not know how much.

The first group I cast up was about Bhn 15. I loaded up a bunch from 42gr to 48gr of IMR4064. The groups were poor from the start. I went back and loaded up some more from 32gr to 42gr. Groups were fair at the start, but the accuracy abruptly took a nosedive shortly after I started and the barrel started leading a couple of hundred fps above that.

I heat treated the same batch of bullets and got them up to Bhn 20-22. Loaded them up again and tried them at the range. By increasing the hardness by nearly 50%, I only got the velocities up about 200fps. Interestingly, the leading started showing up AFTER the accuracy took a nosedive again, not before or at the same time.

I later went back with the loads and velocities I got from these tests and figured what the pressure was (with a Powley Computer). The pressures where the accuracy took a nosedive were very close to what the Bhn x 1422 number predicted.

I am shooting a 375167 right now that is cast and heat treated to Bhn 37-39. I can go to full loads with that one. If I had started out with that, it would have saved me a lot of time and effort.

I have no doubt it works in a rifle and have never disputed that at all.

I've only disputed it fr pistols and more specifically 357 magnum revolvers. As stated in the 2 posts I've made.

I don't recall the article making the distinction between the 2. Sorry if I just misread and misunderstood what you said. When I tried to reread the article is gave the 404 internet error.

Are you stating all this for rifles only? I'll butt out in that case as I have no experience, opinion or interests in long guns.

[HangFireW8]

I am convinced that pressure rise time has as much or more to do with the problem of obturation, deformation and accuracy as the single variable of peak pressure.

I don't think I'm the only one, as there has been much discussion on this board of spanking hard boolits to get them to seal with faster powders, long slow pushes with extra slow powder for accuracy, etc.

I started out with the Veral/Lee formula and had (mostly) really good luck with it. Then I violated the rules, first unintentionally and then intentionally, and had some good luck (and bad) with that as well (both handgun, rifle, plain base and GC).

Now, when I start with a new combination, I mix up a melt according to the 90% deformation rule and work from there. Where I end up depends on my results, not the rules.

-HF

[Bret4207]

I won't disagree that general guidelines work fine with cast. I just believe there are variables and exceptions that rule out most hard and fast rules ( no pun intended).

[Harry O]

I won't disagree that general guidelines work fine with cast. I just believe there are variables and exceptions that rule out most hard and fast rules ( no pun intended).

This is something we can agree on. There are no "hard and fast rules" in most things, especially casting. However, this is something that will always work. It may limit an experienced caster, but it will work. That is something that beginners can use and rule out at least one reason for failures. Doesn't anyone else here remember failures when they first started casting and wondering what, out of all the possible reasons for it, what happened? When you get more experience with casting, you can SOMETIMES break the rules and get away with it. Other times, you can't.

As far as handgun vs rifle rules, I cannot speak with any authority on that when the rules are broken. I have not done any extensive testing with handguns. However, I know that when I follow the "rule" with handguns, I don't have problems. With rifles, I have done several tests after the one I detailed above. The rule has proven to be true for every test I have done. I have not had any luck finding out how to break the rule yet (in rifles). Everything I have tried above Bhn x 1422 has failed. Sometimes spectacularly.

That also means that I have had to do some experiments with very hard lead (above monotype at Bhn 28). They appear to have some rules, too. No need to get into that now, though.

[1Shirt]

Think along the lines of Bass and Felix. Been following this thread to the point where I can't remember all of the back and forths. Hated anything in school that resembled any form of math, and formulas etc. so have avoided it/them when it came to casting. The exception being Bh on my cabin tree, and readings on my chrono. I cast hard, water drop, and am sucessful at least in my own mind. I like bh in excess of 22, and vols between 1600-1800 fps for rifle, and 1000-1200 in handgun ctgs. I enjoy casting, sizing, lubeing etc. but I enjoy shooting more which is the reason I cast. When it gets to textbook for me, kind of back away.
1Shirt!