Ok, so I have a question about my BH convertible. I am going to be loading up some trials for the acp cylinder soon. I had some decent luck with the 255 in my colt cases with right around 6 grains of Unique. Very light load. So is there some reason I am not seeing that I cannot put the same load into the acp cases?
The reason I ask is first off I know the acp cases are rated at a higher pressure than the colt. 20,000 versus 14,000 give or take. So I would think it would be fine. But then I pull out some load data and of course I cannot find any for the 255 grain boolits I want, but for 230 grain cast lead the max charge is listed as 5.5 or so grains of Unique.
I know that as you go up in boolit weight you generally drop in powder charge, so that would mean that 6 grains of Unique would seemingly be way above what the "trend" is.
So what gives? Is there something I am not considering here? It the same gun, just different cylinders. Same boolit, same powder, just different case. But the acp case is rated for higher pressures. Would the same powder, primer, and boolit produce a different amount of pressure in another case with it being of the same diameter? The only thing I can see different is the amount of air space, but usually more airspace lends itself to more pressure correct?
Thanks for the help.