M&P 15-22's tips for added level of safety.

[Smallbore]

A few years ago, I bought a pair of Performance Center model M&P 15-22's so that my wife and I could compete in local .22 Sporter matches. At the time, I wasn't aware of the out of battery discharge issue. Both of ours were the updated bolt face model.

Despite this, hers OOBD'd once and brass hit me in the neck.
If you read after action reports, you read about mine that OOB'd, and hit her in the arm back in 2022.

Since then, neither gun has had an issue after multiple thousands of rounds. These are the tips and tricks that I learned to keep them running without issue.
#1) Clean ammo.
Avoid ammunition that uses thicker waxes as lubricant. Norma TAC-22 shoots remarkably well, however, the wax leaves residue in the bolt face, which attracts the unburned powder and builds up in the bolt face. This is how I got hit in the neck. If you really like TAC or some other waxy ammo, check the bolt face every 250-300 rounds.
2) Avoid ammunition with polymer or powder coating (this is especially important in the Performance Center models with match grade chambers).
Example: CCI Clean RealTree. I found this out after my wife got hit in the arm.
I went home and mic'd 200 rounds, the projectile diameters varied from .2235 to .225. All of the .225 diameter projectiles were green polymer.
3) Proactive maintenance. Clean the bolt face after you're done shooting on Saturday. Clean the entire bolt and chamber after the weekend.
4) Use a brass catcher.
Brass Goat makes a clip on catcher that can be run with or without the hopper. Running without the hopper avoids interference with mag changes, but you're going to want to run long sleeves and a shooting glove. Learned that the hard way.
The standard size hopper does get in the way of mag swaps, however they just released a mini hopper, makes policing your brass a whole lot faster.
In the event of an out of battery discharge, the Brass Goat would stop shrapnel in its tracks, with or without the hopper.

5) Not really a tip, but definitely a trick. Upgrade to a Volquartzen Competition Bolt. The surface is so smooth that field cleaning it takes a cloth and a Q-tip. Also takes less oil on the slide rails. Less oil means less debris to gunk up the works.

Hope this helps!