I got one a few days ago and have had it to the range once.
I also got six extra mags for it. I found that the feed lips of the mags were razor sharp right where they engage the rims of the cases, as one would expect from punched steel. You could really feel the friction as the lips gouged into the case rims when sliding the rounds back against the rear of the magazines when loading them. So I smoothed them all off somewhat with some 1200 grit sandpaper before even heading out, and that reduced that drag somewhat.
Shooting CCI Mini Mags to start off, I had zero issues for the full 70 rounds (all seven mags loaded up with the MMs).
Then I tried a bunch of Federal 510b that I had, and experienced a number of failures. Mostly with a couple of (and one in particular) magazines.
The first round, chambered by slingshotting the slide, always fired. But the next round would fail to be picked up, and the gun wouldn't be cocked after that top round was fired. Manually racking the slide to load that second round allowed the gun to always fire the rest of the rounds in that mag.
Of course, the mag spring is pushing up its hardest for the first few rounds, and while it would chamber a round properly when slingshotting the slide for those top two rounds, that second round wouldn't feed properly on its own.
That makes me think that there was a lot of drag on the slide from the 2nd round pushing up against the bottom of the slide as it tried to move back, and the 510s didn't have enough snort to send the slide all of the way back, so it didn't cock the gun or pick up that next round.
I need to examine the bottom of the slide and see if there's something that needs to be smoothed up or greased a bit to help with that. And perhaps the slide or the rails it runs on are not smooth yet, and that extra upward force creates friction in a number of places, retarding the backward movement of the slide.
I also had a couple of failures to properly feed where the next round ended up pinched between the breech and the bolt face, and just dropped out of the mag well when I pulled the slide back (after first ejecting the magazine, of course). I didn't pay enough attention to know if those happened with those same two magazines.
I need to label the mags and pay more attention the next time I give the little gun a try.
To me, 510bs always feel like they have a weaker, or more "mellow" impulse when firing them than the Mini Mags. And I think one of the things that makes Mini Mags (and Blazers) so reliable in most semi-auto pistols is that they appear to use a fast-burning powder that creates a "sharper" impulse, and that's a plus when trying to operate a blowback pistol, especially ones with short barrels, where you need every advantage you can get to blow the slide back firmly.
I specifically made sure not to limp-wrist the little gun after I started having the failures, but that didn't make any difference. The 510bs, and those two mags in particular (especially one of them) seemed to be the culprits.
I may try a more diligent polishing of the feed lips and compare their exact positions against the "good" magazines to make sure they're not bent out of position in comparison.
For me, the gun consistently shot high and left. Not terrible, but obviously not right where I wanted it. Decent groups, just a bit high and left for me.
The barrel in mine seems rather "unfinished", with both the "crown" and the entry into the chamber being razor sharp - I mean, it'd cut you if your twirled it against your fingertip. I may look into doing something to remove the sharp edge/burr at the crown end, and probably also smooth up the entry to the chamber.
I have one of the LCPIIs in .380, and it's a peach. Not one failure of any sort with it, and it shoots nicely for me. I did put some white paint on the front sight of that one, and I will probably do something to the sights of the .22 as well. I am nearsighted and wear progressives, and I can't really focus on the sights, and having them all black doesn't help. So I may just have been misinterpreting the blurry mess that is my sight picture with this little gun.
The first thing I noticed was the amazing muzzle flash that one sees from the shooter's point of view when firing, particularly, the Mini Mags. This was at an indoor range, and this may not be as visible outside in the sun.
I like the little gun, and will work with it a bit and see if I can make it less picky about the ammo.