Load development is my favorite part about shooting. I typically only do it for rifles and revolvers though. The 10mm has the potential to be useful with exceptional accuracy, but I have to get better with the gun to be able to capitalize on it. I will probably refine a hunting load for it, but these HAPs are really just for making noise and being fun to shoot. I'd like to average 650+ lb/ft ME with them. I'll push some Sierra or Nosler pills harder, but safely.

So, I had a good time shooting the Sig for the first time today, despite not recovering all of my brass, but that's another story. I picked up a box of Sig 180 FMJ with advertised velocity of 1250 FPS to compare with my handloads. Now, I do not think I reached that pressure with any of them, especially the Power Pistol, but I did find some decent accuracy with all of the charges. The starting charge for the PP was barely enough to function, and two rounds hung up trying to extract. I noticed the ejector imprinting on the case heads pretty hard when testing the PP, and verified it is doing the same with factory loads as well, so must be ok. I'll work up higher for both LS and PP. These are the groups shot at 5 yards with the five charges of PP. did not get a pic of the LS.


This is a pic of the case heads. Still excited about the potential for this round, but still kinda sad I didn't buy the Ruger GP100. Revolvers are so
Much nicer to brass...

Thanks for the insight. I haven't done enough research yet, or have enough experience with my specific pistol to know how it reacts to max pressure, so I'm kinda treating it like a new rifle. Work up slow and steady, watch for pressure signs, and stop when I'm happy with accuracy and the sound it makes. I don't expect it to turn heads like my 44, but I want it to be fun, like my 44.

I'll be honest, and admit one mistake I made as well. The different sources of 10mm load data for 180 grain bullets and both Longshot and Power Pistol got me a bit cautious. I loaded both test groups with 10 each from 7.2 - 8 grains at 1.260" OAL. I MEANT to load the Longshot from 8.2-9, but I'm an idiot and read my 10-10 wrong. Oh well. Not too little to be worried about detonation, I just hope it's enough to function and clear the cases without mauling them in the action. I guess I'll break down and buy some factory ammo as well as a baseline for ejection pattern and what it's like at factory pressures for real 10mm ammo. None of that weak "40 stout" I've heard about. I didn't buy a 10mm to shoot 40. That's what my G26 is for.

Got my first rounds loaded up. 180 HAP and Longshot and Power Pistol. Gonna be good times!

What store? 

Will do. Thanks!

I've already made plans to build a AR-10mm. It has to happen.

Pretty little sidearm you got there. Very nice.

You'll have one on Saturday!

That's the only list I keep.

Quote from: Kenk on April 24 2019 06:36:33 PM MDT
Welcome astrocreep!

Muchas garcias! 

My LGS does me favors, little ones anyway. I got out the door for a blonde one over a grand. Not bad for the night sights, 4 mags... do wish it came with a threaded barrel. But, then I'd be forced to buy a pistol caliber can.

Quote from: The_Shadow on April 24 2019 07:04:59 PM MDT
Very nice, good luck with you handloads...

I prefer experience and caution with my handloads, but if I have to fall back on luck, I will.  Thank you sir

Quote from: Pablo on April 24 2019 07:02:02 PM MDT
VERY nice!

I appreciate you saying so! I've heard from one guy that has one that he had extraction issues, and some of Sig's recent reputation in the poly-wonder world has not impressed me. The relatively low cost for this firearm also makes me somewhat apprehensive, but I'll stay hopeful. Thanks again!