I know that a S&W 15-22 magazine will fit (a bit loosely) in a Mil. Spec. lower and a Ciener/Blackdog will not fit a S&W mag well.

Which other "AR" .22 rim fire magazines are interchangeable?  The M4 Colt/Walther ? The Mossberg AR-.22  ? etc.

I'm looking for an "AR.22" for my wife and I don't want to buy into a proprietary system. I currently use a DPMS Bull Barrel upper. and would
like something lighter and less expensive, for her, that uses the Ciener/Blackdog magazines.

Jack Kacee was the dog

Pretty sure the Colt and Mossberg are definitely proprietary mags. As they are a complete Proprietary design same as the SW 15=22

I would suggest if she wants light get another AR lower, upper reciever, CMMG bolt and a Taccom ULW barrel and make her a rifle. One of our complete rifles we put together using a CMMG bolt and Taccom ULW barrel weighs right at 5.5 pounds total. Thats with a rifle length aluminum JP free float handguard and a Magpul stock.

It is so light, easy to aquire targets quickly and pretty darn accurate...

We use the SW mags with a better mag adapter in our dedicated uppers and they are great..


..

Or go to AA & get you a .17" HMR tackdriver.

Has she looked at the S&W 15-22? light enough? unless you have a bunch of BD mags it would be cheaper to buy the 15-22, a better mag adapter for your DPMS and switch to S&W mags.
EDIT: Just checked, I thought the better mag adapter would work with your DPMS, it won't... scratch that Idea

I don't know what "Less expensive" means to you but as stated a TACCOM UL upper and polymer or even aluminum lower would be light weight and will use the BD mags... Cheap it's not but it is one helluva set up

I have a DPMS 22 upper.  Works great.  Uses the Blackdog mags.  I would definitely recommend it.

Any TACCOM or CMMG 22 Upper will work with Black Dog Mags.  I prefer TACCOM over CMMG.

MAHA

Tactical solutions also makes some very nice light weight bull barrel uppers, and full AR 22 rifles check them out and see what u think, id post the link but my dumb ass dont know how lol.............

Thanks Guys, I'll see how she does with my brother's S&W 15-22 and go from there.

If she wants something heavier, I'll probably go for something in a CMMG M4 profile upper, to
fit a Mil. Spec lower and maintain some kind of standardization.

I'd hate to have 3-4 incompatible AR style magazines floating around here.

Jack Kacee was the dog..