It's a long, boring, story, but I finally got this pistol working reliably. Pictures will be coming, but it was snowy and muddy at the "range" yesterday, and I was in a hurry by the end.
I ended up getting a dedicated 9mm lower from CMMG for several reasons. It's enough trouble (to me) to push out a roll pin and remove the bolt catch, that once the mag block insert is in, it's essentially a dedicated lower, anyway. I'm certainly not going to switch calibers at the range. Plus Gunnies had the lower with trigger group, selector, grip, bolt catch, and mag catch for only $250. The stripped CMMG lowers go for $199 from Brownells, and that's before shipping and FFL. And that leaves my other lowers free so I can build my long range rifle and my .300 pistol.
I learned a few things in this process, so I'll share them here.
Palmetto State Armory really does have good customer service if you know how to navigate it. Don't e-mail them. The only e-mail address I got was a generic one, so I would reply to an e-mail, and someone different would reply to me. They never figured out that I was replying and would treat every e-mail like it was a first contact with their CS dept.
If you have an issue with PSA gear,
CALL THEM. I had gotten a nice letter back from the gunsmith saying he had upgraded my BCG to a slightly improved newer model, and that he had fired more than 30 rounds through it with no issues. But they sent me a new mag block that was clearly manufactured wrong:
Image here.I noticed it as soon as I unpacked the box, but I took it to the range anyway, just in case I was crazy. I only managed to fire one shot with it, and that was lucky. So I called about that in November (I originally ordered this in May), and she offered me a full refund on the whole kit. I was tempted, but now I'm glad I resisted.
Finally, yesterday, I sent about 100 rounds downrange from 4 mags (IWI, metalform, promag), and didn't have a single issue. My son and I have chronographed several 147 gr. defense loads, and done ballistics gel tests comparing the same loads out of a 4" barrel to the 10.5" and I'm really impressed. Ballistically it's not quite .357 Magnum, but a 147g HST at 1370 fps is formidable, with impressive penetration and expansion.
I don't like the Sig Arm Brace. I shot without it yesterday, and I could tell a difference, but I'm not sure the difference justifies the cost or the weight. If I had shot this pistol with and without the brace before I bought it, I would have bought mags and ammo instead. Now I know. It's heavy. This pistol isn't light, but the weight and balance difference with the arm brace is significant.
In conclusion, I love it. It's fun to shoot, and easier for me to shoot accurately and quickly than a typical pistol.
The mag block inserts work for lots of people on the interwebz, so I think I just got unlucky.