Bluehawk wrote:Has anyone tried IMR 4198 powder for the cast, 300 grain bullet weight range? I've always had great results in my Marlin 1895 .45-70 with it, and good results in my .458 Win Mag and so I'm curious wondering how it might work in a gas system.
Bluehawk-
The forum is always open to learning the results of experiments, so have at it and let us know what you learn.
However, you are tackling simultaneously two areas of 450B reloading practices that have not as yet produced really satisfactory results: cast bullets, and slower powders.
I posted a list of some of the more informative threads on cast bullet shooting, and the list was made a sticky:
CAST BULLETS discussions . There are 17 threads listed there, and taken together they describe a lot of pretty careful work by pretty experienced cast bullet shooters. You might save yourself some time and aggravation in following blind alleys if you read them attentively.
In the 450B, 4198 is a slow powder. It may be helpful in selecting suitable powders to think of the 450B cartridge as a super magnum pistol cartridge, rather than a mini-45-70 or mini-458 WM. The 450B has a bit less capacity than the 460 S&W, and in most ARs the 450B has to function at a lower max psi. The 450B an extraordinarily versatile cartridge, but it is limited in case capacity. In both the 450S&W and 450B, 1680 is about the slowest powder that will function adequately.
I started to play with some 300-grain cast bullets in my bolt guns briefly before the local range was snowed in. I was intending to try Accurate 5744, which can produce excellent results with heavy and light loads in straight-walled cases and with cast bullets. If your 4198 experiments don't work, you might try that powder. I've no idea how it will work with the AR platform, however. The Accurate loading manuals provide loads for the 450B with 5744 and jacketed bullets. It also shows loads for the 460S&W with jacketed and cast lead bullets using 5744. However, the 460S&W full-power cast bullet 5744 loads produce pressures well beyond the 450B max, and are almost certainly unsafe if extrapolated to the 450B. The reduced loads for the cast bullets with 5744 might be interesting. However, pressures are unknown.
BE CAREFUL.
--Bob