.357 SIG shooting too fast ~ Need suggestions

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nippon

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Hello all. This is my first post here. I have greatly enjoyed reading other people's comments.

So I just started reloading .357 SIG and have a slight problem. I'm using power pistol with a 124 gr HP. Every manual/online resource I've seen puts the starting powder for this load around 7gr. I started this at 6.9 just because I'm new to the round. After cranking out several on my Dillon, I took it to the range.

Shooting through my buddy's chronograph, the round was zipping off at around 1600 FPS! The loading manuals have this load at 1200 so we were concerned.

We shoot my Glock 22 and the .40 came in right were it was supposed to (around 1000 - 1200 based on the round). We even tried the AR and got about 2800. So I don't think that it was the Chronograph.

I've checked and rechecked my powder throw and it's dead on. I know that extra powder is not getting in there.

Any suggestions on things I could check out? Anyone have any experience with power pistol in the .357SIG?

THANKS!
 
Well, you simply cannot be getting 1,600 FPS with that load, or any other load, that's for sure.

I'd suggest you were too close to the screens and clocking the muzzle blast.

rc
 
Nippon,

There is no way 6.9 grains of Power Pistol can make the velocity you mention with that bullet in .357 SIG handgun. I routinely use 6.5 grains of PP/125 grain JHP in 9mm, and it averages a little over 1200 fps depending on primer from my 4.9" Beretta. Your velocity should be lower due to larger case capacity. Even with pretty serious bullet setback, I don't see how 1600 fps is possible.

IMO, either the propellant is wrong/defective/mismeasured, or more likely the chronograph is getting blast tainted results, not set up correctly, or defective. Even with a 90 grain bullet, 1600 fps is not happening with the info given. Just a note, and not saying it applies here, but PP and Bullseye look 99.999% the same, and have been mix-up up before. From what I understand, PP is basically Bullseye that has a very extensive treatment used to alter burning rate/pressure curve, and both look virtually identical. I use both, and am extremely careful making sure not to ever mix/use in place of each other.

Good luck.
 
Any powder that would give enough pressure to launch a 124 grain bullet 1,600 FPS would take a .357 SIG apart at the seams!

rc
 
Thank you all for these. Come to think of it, I may have been too close. It was actually my first time using the chronograph. That's strange that I would have gotten that resullt from the .357 SIG and not from the .40. I was in the same spot when I spot both of them. I'll try these rounds again from further away.
 
Yeah

I've also found that you need to let the chronograph warm up. Mine will suddenly shift in velocities after about a minute.

Also applies to digital scales in general.
 
Thank you all for these. Come to think of it, I may have been too close. It was actually my first time using the chronograph. That's strange that I would have gotten that resullt from the .357 SIG and not from the .40. I was in the same spot when I spot both of them. I'll try these rounds again from further away. ]
Click to expand...

PP is pretty boomy/flashy, even with less than max charges, and perhaps this explains some of the problem. I can not vouch for this fellas Power Pistol loads, but snappy might describe them @1500 fps w/ 124 grain bullets:

http://www.handguninfo.com/Archive/www.Pete-357.com/rel.357.powerpistol.htm
 
Try moving the screens out to 15' and shoot some more rounds across it. A lot of people try to get the screens close to the muzzle, since they think they're going to lose too much velocity at 15'. Instead, they get false readings from the muzzle blast.

Hope this helps.

Fred
 
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