Mine came in ... and was promptly lubed and taken to the range.
Fired about 80-rds of various 10mm factory ammo, and then 16-rds each (2 mags full) of two different handloads - one being a 165gn FMJ training load (about 1300fps), and the other a 220gn "woods load" developed for my Glock 40 MOS using poly-coated HC boolits from SNS. This 220gn "thumper-load" runs about 1225fps.
Not one bobble or hiccup occurred. Not only did I use the two 8-rd 10mm mags that came with the pistol, but I tried some ACT 8-rd .45acp mags that I've used as practice mags for my Sig P220, which is an older "Made in W.Germany" model.
The 8-rd .45 ACT mags hold
9-rds of 10mm Goodness perfectly, and they loaded, fed, and ejected perfectly too. The ACT mags give you a 9+1 gun, or a 10x10.
That's the only "con" I could find about this gun
if it has to have one: Sig could've easily engineered a 9- or even a 10-rd 10mm mag and still retained the same frame profile. Looking at an ACT .45 mag side-by-side with the Sig 10mm mag, the dimensions certainly appear identical. Ditto for the 8-rd stainless .45 Sig factory mags, of which I have five. Same exterior dimensions as the 10mm mag.
From 35-feet, the Sig shot groups ranging from pretty-good-to-fantastic with the ammo I put through it. The Sig-Lite night sights were dead-nuts-on too. A good part of this first range session was simply trying to get used to the recoil and handling characteristics of the big Sig, although the range time I've had with my .45 P220 helped.
Of note for the 10mm history buffs here, .... Sig imparted two Bren Ten-ish qualities to this pistol. For someone like me, who's actually handled several BTs and shot exactly one
way back in the day, I noticed them right off: the first is the matte blue slide riding over a brushed stainless frame, a beautiful combo I've always liked. Second is, like the BT, this Sig was given a true 5-inches of slide and barrel. That gives it noticeable weight but also balance, and it surprised me how well and easily this pistol pointed during shooting. It doesn't feel muzzle heavy, but also doesn't feel back-end heavy, like some short-barreled, large-frame pistols do.
Had this Sig DA/SA 10mm hit the scene in the late '80s, I'd venture to say we'd see more cops today carrying one on-duty or off.
The Sig ate everything from the mild-ish Remmy 180gn FMJs (1150fps) to Sig's own 180gn ball (1250fps), to DT's early and quite hot (white box) 165gn Golden Sabers (1425fps).
Very controllable recoil with all the full-throttle stuff, ... and with ".40-level" 10mm ammo, it felt like shooting 9mm+P.
DT 10mm 165gn Golden Sabers
Great gun, great shooter, and definitely a keeper!