SAFETY WARNING!
Many of you know I focus my development efforts on the .500 S&W. I have designed bullets, developed loads, done extensive testing, had the S&W factory pressure test my ammunition, and even had them build a limited production gun to my specifications. One S&W engineer flatly states that I have done more load development for this cartridge than either the S&W factory itself or the powder companies. I thought this last might be an exaggeration but after something I saw today, I'm not so sure.
I have been using the computer simulation Quickload and have found it to be very close in velocity and pressure predictions to the empirical results I have obtained both from my own chronograph sessions and S&W's pressure testing of ammunition that I loaded.
Whenever I see load data from a powder company that includes pressure figures (such as Hodgdon), I run the numbers through Quickload to see how they come out. In almost all cases the numbers agree pretty closely, but once in a while something makes me scratch my head a bit.
Well.
Yesterday I went over some new published data I hadn't seen before, and my hair stood on end. Go to http://www.accuratepowder.com/wp-con...2016_Web-1.pdf and scroll down to Page 21 for S&W .500 data.
I haven't checked every load with Quickload, but some of this data looks absolutely insane! Let's look at their data for the .500 using the Hornady 500 grain Jacketed Soft Point. They load this bullet to an OAL of 2.070".
They list pressure data only for max loads, not suggested "starting" loads.
4100 Powder
Starting load 28.3 grains and (according to Quickload) 39,700 PSI.
Max load 33.2 Gr. They say 52,300 PSI, QL says 64,200. Okay, I've doubtless loaded some rounds at this pressure...
Ramshot Enforcer
Starting load 28.3 grains and (according to Quickload) 45,200 PSI.
Max load 33.2 Gr. They say 52,300 PSI, QL says 73,000. This is starting to worry me...
Accurate 5744
Starting load 33.9 grains and (according to Quickload) 64,300 PSI. I don't like this...
Max load 39.9 Gr. They say 52,300 PSI, QL says 117,600. QL also puts this charge at 127% loading density(!)
Accurate 1680
Starting load 39.4 grains and (according to Quickload) 67,300 PSI. (115% loading density)
Max load 43.7 grains. They say 54,700 PSI, QL says 112,400. QL puts this charge at 128% loading density.
Okay, let's try the Cast Performance 440 grain WFN loaded to an OAL of 2.005" with these last two powders:
5744
Starting load 36.3 grains and (according to Quickload) 43,100 PSI. (107% loading density)
Max load 42.7 Gr. They say 55,400 PSI, QL says 89,600. QL puts this charge at 126% loading density.
1680
Starting load 42.7 grains and (according to Quickload) 89,500 PSI for a starting load! (126% loading density)
Max load 47.5 Gr. They say 47,750 PSI, QL says 182,900 PSI! QL puts this charge at 140% loading density. I am at a loss for words...
Somebody please double check my numbers...