I have wanted a 9mm Ar for awhile, i came in the pistol and rimfire side a few months ago to see what i wanted and to get it. I did not get one but i plan on getting one soon. I have a bushmaster xm15-e2s 14.5" carbine in 5.56. I want to use the bushmaster 9mm polymer or metal mags that they have on their site and i see some cheap 9mm uppers on model one sales.

To use the bushmaster mags what mag lock do i need, if i use these mags and maglock, does it have to be a upper specificaly for that or can anyupper use any magblock and mags? can i use the onel from model one sales and bushmaster mags sorry if im not clear enough i cant really think of how to explain it and im completly new to the pisol calibers.

the bushmaster mags actually look like sten mags or some kind of sub machine gun are these just new ones or a completly diffrent mag they just look the same to me?

thanks for all the help and any info is appreciated. I also like pics since i dont know what i want to do to this one except for SBR

As far as upper receiver goes,  you can run a 9mm setup in any 223 upper out there.  Some like to have the shell deflector but mine will eject 90 degrees to the right without one.  After checking bushmasters website, it looks like they are using a pro-mag 9mm mag, which looks like its using the the colt setup. Pretty much any magblock and colt style mag should work.  I can so that I havn't had real good luck with the pro-mags that I bought, I would suggest c-products or a couple others.  YMMV

thanks for the fast response, i thought that there was diffrent magblocks for diffrent style mags?
im pretty sure that i would have to change my hammer to? so the basic parts i need is 9mm upper, 9mm magblock, 9mm mags, 9mm hammer

Currently I am running a dpms 223 hammer.  Its rounded instead of notched, and I also have a heavier buffer. Also, just incase your upper doesn't come with it, you would need a 9mm bolt also.

what magblock and mags are you running?