AR rimfire to centerfire?

[Ulmus]

I had a guy at work ask me if a dedicated rimfire AR, like the S&W M&P 15-22, could be converted to a centerfire AR by changing out the upper receiver. 

I told him I didn't think so, but am I wrong?

[robert69]

No, they cannot.
The SW mod 15 22 rimfire lower half is plastic.
Sounds like someone is looking for a cheap mod 15.
I have the performance chamber model, and it is OK, especially when I swapped out the trigger.
Not near as accurate as a Savage 22 bolt I have.

[DanPatWork]

I recently built my lower on a PSA lower and parts kit. I then added a dedicated CHIAPPA ATI .22 upper to it. In the end my total cost was within $50 of the price of an M&P15-22. No it doesnt say Smith & Wesson on it, but it is reasonably accurate to 50 yards and fun to shoot. It also can be converted to centerfire with an upper
change. There are mixed reviews of the Chiappa upper but all in all I'm pleased with it.  Only complaint is the rail on either it or my 10-22 takedown are not in spec.  I can't transfer a scope mounted on qd mounts for the ruger to the Chiappa.  No big deal except I prefer to be able to multitask my inexpensive gear.

[Ulmus]

Thanks for the info. guys.  It's good to know that I was right about the rimfire not being able to have a centerfire upper attached to it.

Yep.  The guy was looking to save some bucks.  Oddly enough, while he'll work on cars all day long, he's a little intimidated about building his own AR.  Go figure.

[billt]

If you already have a .223 AR-15 rifle, Spikes Tactical, as well as CMMG both make .22 LR uppers that will run on any standard AR-15 lower. If I was going with a .22 rimfire AR, this is what I would go with. It's really not that much more expensive, and you're putting together an AR-15, .22 rifle on a forged lower, and an Aluminum upper. Just like any other AR-15. I've always felt this was more desirable than the Polymer AR .22's currently on the market. They can get quite expensive when you start decking them out.

It becomes a much more useful combination as well. You can always put another caliber upper on it if you want to try say 6.8 MM, or .458 SOCOM, or anything else available in the AR world.

[Sponsor]

[WatchManUSA]

I picked up a CMMG .22 bolt replacement. I just change out the bolt and it becomes a .22lr. Works good enough for me.

[DanPatWork]

I picked up a CMMG .22 bolt replacement. I just change out the bolt and it becomes a .22lr. Works good enough for me.

I'm certain this option works for many people.  I chose not to go this route because I didn't want the gas tube and barrel fouling associated with shooting .22 through the conversion in a 5.56 upper.   


Eventually a CMMG upper is likely for me, or even a TACSOL AR-22 SB-X as a suppressor host.
http://www.tacticalsol.com/tshome/ar22-22lr-conversion

[les snyder]

if this is a thread shift, then I'm showing off a little.... a local club shoots a 3 gun format with .22lr for the rifle... a lot of fun, and can be shot on a shorter venue like a 35y pistol range... my CMMG conversion started as a drop in, and as commented left a lot of residue in the upper receiver and trigger group... I got pretty poor accuracy with the .22lr thru the .223 barrel, no better than 3 1/2" at 50y... the dedicated .22lr barrel dropped that to about 3/8" at 50y... I get a lot of kidding about the scope cost, but it was sitting in the gun safe...