I have been considering picking up my first .22 AR and am considering these two. Any reason one might be better than the other? I know Smith’s customer service is great, so that is leaning me in favor of the M&P. Do these take the same mags?

I have a 15-22, I’ve handled several H&K 416-22.

The H&K is far, far nicer.

Don’t know about magazines.

I handled a S&W and it felt like a toy.  I went with a dedicated upper to pin onto my lowers.  It was $300 from PSA and shoots great.  I then built another 9" upper for my "pistol" lowers and share the bolt between them.  I would build again before buying a toy.  RTB has bolt/barrel combos in stock now and again, sign up for alerts there.  A 22LR upper is stupid simple to build.

I bought an H&K for my infant son in December and just sold it, new and unfired. I feels much nicer than a M&P 15-22, but it isn't very customizable. It's got a large man hand grip that could be changed with modification of a new grip, but things like the trigger are not changeable. It has its own mags which aren't too bad, but they are more expensive for the 30 rounders ($40 ea, I am still trying to get rid of mine). I ended up building a 9.2" pistol for my son in a PSA receiver we already had. It'll be a few years before he can shoot it, but I selected parts that will be better sized for a kid.

All the reviews for the H&K are great though, which is why I originally bought it. It felt like an AR.

If you want something that looks "cool" and is a pain in the butt to clean, buy the Hk. If you want an under study for its centerfire brothers and a lot easier to maintain buy the S&W or Tippmann Arms.

I really like my Smith and Wesson.
With a mod to the extractor with a volqsteen ( sp ) its runs like a top suppressed and is a ton of fun to shoot. Does feel a tad bit cheap though but for me thats fine, its a training weapon basically.

Build or get a Tipman

The Umarex imported HK 416 is a complicated rimfire design in a shell to look like an AR-15.   I’ve shot some of these but I don’t care for their quirky design and would buy a S&W 15-22 which I have also used.  I haven’t used the Tipman but recommend buying or building a CMMG pattern upper.  Right to Bear is the go to place for 22 rimfire upper parts these days.

Given the choice between "HK" Umarex and S&W, S&W 15-22 all the way.

S&W 15-22 has a proprietary lower, uses S&W mags only; 10 or 25rd. Plinker Tactical made 35rd mags & BlackDog makes a 50rd drum.

IMO the S&W 15-22 is the most reliable 22LR on the market.  It takes most standard AR triggers (Geissele, Larue, Hiperfire all work), has LRBHO, Radian makes safety/CH, regular AR furniture fits.  This opinion is based on 9 years coaching a junior SASP Team and using 10 S&W 15-22s, now 10 Tippman M4-22s, shooting 60,000rds of 22lr a year.

For those who say the 15-22 feels like a cheap plastic toy gun, yes... but if you're teaching kids to shoot, the light weight is a huge bonus.  And if you look at most Steel Challenge, Rimfire Challenge adult competitors, they're paying $$$ to get rimfires under 4#, so the light weight is a bonus there too.

If you want the most accurate 22LR AR upper, get a JP.  If you want a matched-weight training clone, get an AR22 upper.  But for $399 brand new, the 15-22 is a great deal.

Thanks for all the info. I wasn’t aware that PSA made a .22 upper. It’s out of stock, of course, so it doesn’t show a price. I will likely go with the Smith or the PSA upper.

The Palmetto State Armory 22 LR upper uses the CMMG pattern bolt and barrel.   Reports on PSA 22 LR upper are good.  Get on the email notification and maybe you can snag one.

The PSA 16" AR22 upper is a great value.  Bought one new, attended my 1st Appleseed 25m using a carbine lower and made Rifleman on every attempt.  Its heavy, so mimics the weight of a 16" 5.56mm upper.  The 13" handguard is plenty, because 22LR barrels sit 1.5" farther back into the upper receiver vs a 5.56 barrel.
One thing the S&W M&P15-22 won't do is shoot tight groups all day long.  That plastic upper receiver will flex with the heat, and groups will open up.  My buddy's JP AR22 upper shoots moa all day, accuracy is at bolt gun level.

I just went through this recently,  had a thread in GD.  While the HK is metal and felt like an AR, it had some negatives (barrel being sleeved and too many proprietary parts). Lots of people like the MP22, but it's all plastic which I didn't like the feel of when I handled one.   Most people recommended building your own upper which is easy to do if you can find the parts in stock.  Right to bear arms seems to be a good source for their brand of parts which are CMMG patterned (they also sell CMMG parts).

I got lucky and found a 9in CMMG complete upper online (optics planet actually had 1 in stock!).  Slapped a Sparc AR red dot on it that I had left over from another AR15 this weekend.  Crazily, I didn't even have to sight it in, it was hitting steel out to 100yards.  So I'm happy I went the upper route.

Glad I still have my Sig 522. Feels like a real rifle, shoots well and uses Blackdog mags.
Shame sig dropped them.

I regret not getting one while they were avail. That was the first 22 rifle I shot and I fell in love with the aesthetics of those guns too.