44Mag Pressure?

[Forester]

I have a S&W Mountain Gun my wife gave me last Christmas, I have tried a handful of powders and bullets with the gun but it always shows pressure at powder charges at the bottom end of the load books.

For example, with H110 and Hornady 240grXTPs I have to drop 2 grains below the Hornady book just to get to a load that only shows some primer flattening.

Any ideas what could be causing this? Sorry no Chrono data yet to see if the pressure has corresponding velocities.

[steve smith]

I'll venture to say that relying on primer flattening is not the best idea. The only pistol round that I've even considered using primers flattening as a sign of high pressure was my dads S&W 460 mag. Beyond that I've always used a chronograph to approximate where I was in the loads pressure range.

[Loner]

H110 is not a powder you want to drop below book loads. 3% under max load is
all you should ever reduce H110. There has been more than one smith blown up
with H110 over the last few years.


http://data.hodgdon.com/main_menu.asp

[MagnumManiac]

H110/296 should be used with near max loads and a very heavy crimp!

Have you fired any factory rounds through your gun?

If so use them as a comparison to your primers, other than that you can only guess at what pressure you're getting.

24gr of H110/296 is what I load with 240gr pills, this has been a very safe load in numerous pistols and lever rifles.

[Forester]

Originally Posted by MagnumManiac

H110/296 should be used with near max loads and a very heavy crimp!

Have you fired any factory rounds through your gun?

If so use them as a comparison to your primers, other than that you can only guess at what pressure you're getting.

24gr of H110/296 is what I load with 240gr pills, this has been a very safe load in numerous pistols and lever rifles.

The crimp was what I would call middle of the road, hard to quantify with a roll crimp. I did not start below book loads, but with a load right in the middle of what a couple different books recommend the primers were flattened, dished, and generally looked like WAY to much pressure.

In addition, the gun shows pressure early with every powder I have tried. These include: 800X, 231, Clays, and HS-6 (All powders I had on hand)

I used to load and shoot 25-30,000 rounds a year worth of 9mm, 40S&W, 45ACP, and 38spl. when I was shooting USPSA and IDPA regularly so loading for a handgun is not new to me, but I have never seen a handgun behave this way.