I have 3 Beretta’s, and a near forth in an 80’s vintage Taurus PT-99.  The PT-99 and Beretta 85 have never jammed on me, the Tomcat every blue moon.  The 21a, stainless, in .22LR is a different story.

Lots of issues with that pea shooter – both fired cases not being extracted from the chamber, and/or not loading up a fresh round.

For the extraction issue, I’ve found that the chamber need to be scrubbed out to a very high level of clean.  The .22 bore brush isn’t enough to get all the crud out, that I guess sometimes causes the cases to stick in the chamber and defeat the wimpy blowback extraction of the round.

So, I use a .25 caliber brush to clean the chamber.  It takes a bit of effort to get that larger size in, and it really gets out dirt that the regular bore brush won’t.

For the fresh round pick up issue, I’ve found that it needs higher velocity ammo to be reliable.  I use ammo that’s listed as 1200 FPS or more (which is the velocity from a rifle barrel, not this little one), seems to throw the slide back far enough to pick up a fresh round.

Anyone have any other tips on making these pop guns reliable?

How the reliability with 40gr Mini Mags? Mine has been at least 99% reliable with Mini Mags.

With about 400 rounds of Mini Mags, I can only remember one stove-pipe and one bad primer.

Hollow point bulk ammo causes issues. I don't shoot these in the 21A.

I have a friend who had the same problem. The pistol was sent back twice and they were told "It fed and functioned 100% for us". I contacted them and asked what ammo they used. They said Remington .22LR.

She has since switched to Remington brand .22LR and it has run 100%. Now I consider this a defect since firearms shouldn't be so picky that only one brand will work. It does work now and that's important.

Why Remington works and other brands do not I do not know.

.22's are notorious for being ammo sensitive. Velocity pressure and bullet profile all influence feeding in 22's. Remington ammo ( which I generally hate for frequent misfires audibly apparent variations in power level of load, a excessive leading of barrels) has a pointier bullet profile. For me I have good luck with just about any cci brand ammo as well. With 22's you have to accept they are ammo sensitive usually. Having said that I have a smith 422 and beretta jaguar which both feed and function with everything

I have a Inox as well as a black 21a. Iirc the reliability issues I had were with one of my mags(think it was a factory mag, I also have mecgars) I had to squish in the feed lips just a hair.

I pretty much only shoot Aguila interceptor rn in them.

Since the run on 22lrs a few years ago, the overall quality of 22lr has dropped in my opinion. A lot of brands that were decent turned into loads that would only be reliable in a bolt gun. CCI has always been my goto in semi auto rimfire pistols, I've had problems with most everything else. My 21a has ran its best when I keep the chamber clean. You can also swab the chamber with acetone or laquer thinner, see if some oil dried in there and is slowing extraction. I've had pistols in the past with rough chambers, I've found much benefit in taking a bore swab and dipping it in flitz or rubbing compound and using it to polish the chamber and feed ramp. The lip edge of the mag can sometimes benefit from this, as I've noticed a burr on occasion that can scrape a bullet during feeding. The wire action recoil spring might also need to be looked at, if it's not tuned right, worn, or is flawed - it could not be allowing the slide to consistently move. Fwiw