Why so many different max loads for 45?

[ZLBubba]

I just started reloading 45ACP recently and as I've accumulated the load data, there's an enormous variation on powder charges. The different manuals have a fairly large spread between min and max, and that doesn't even account for the +P loads.

So what gives? I'm shooting these out of a USP 45 and want to know what I can safely go to. I'm using AA No.2, No. 5, and will eventually get to my Unique. The bullets are 230gr FMJs but once I've shot these up, I'm going to drop down to 185s or 200s. Thanks for your help.

 

[BHP9]

Re: Why so many different max loads for 45?

Look at the first page of the data and it gives the testing criteria.

Preesure barrel of handgun.

Components used etc. They are all differnt, but they are all correct.

If you are using brand x brass with brand y powder, and the data from book s, then you will have to work up your own data, but using the components that are listed in book s then you are good to go.

 

[ZLBubba]

Re: Why so many different max loads for 45?

Ok, so more specifically, let's take data for assorted brass, Winchester large pistol primers, AA No. 2, and 185gr Hornady XTPs.

Looking at AA's data, you can load between 6.8-7.5 gr of powder to a max pressure of 20.4k. However, on the very next page, you can find load data that will take you up to 23k for the +P loads (8.0gr of No. 2).

Are there older 45s that cannot handle the +P loads which is why all the manuals tend to be conservative with their standard 45 load data? How do you know when to use +P loads or the standard loads?

 

[Victor N TN]

Re: Why so many different max loads for 45?

For the 230 grain FMJ bullets, see what powder charge gets you to 850 fps from your pistol. The mil-spec load is a 230 grain FMJ at +/- 850 fps. According to all the tests done in the early 1900s that's the magic minimum number for stopping a man sized animal. I did not say kill. Both Dr. Mann's book of Pistols and Revolvers, as well as Hatcher's Notebook verify the same information found in the Thompson-LeGuard tests.