I want to build a 4.5" 22lr for one of my existing SBR lowers.

Sorry to start another thread on this, but I was unable to reply to some of the existing threads I found when searching because they have been archived and you can no longer reply.  And with that out of the way, here we go.

Reading though the following links (Archive thread 1, Archive thread 2), it looks like most people recommend using the CMMG MK4 barrel kit. Some questions I have are the following:

1) What magazines do you need to use with this kit? Will only the CMMG magazines work or can I use other magazines for it such as the ones for the M&P15/22? Or what about the blackdog mags?

2) It looks like you can use any milspec upper to build it. I have a couple laying around, but I was thinking of maybe picking up one of those Anderson lightweight sport AR uppers as it doesn't have the forward assist and it also doesn't have an ejection port assembly/door. I don't really see a need for either with this build, but if you disagree please let me know.

3) Do you have to use the CMMG CH that is sold separately or can I use any CH like the Raptor Ambi ones I prefer?

I think that is all the questions I have for now, but if I think of anymore I will edit this.
Thanks,
Mav

Topic Moved from SBS to SBR forum...

1. I use Black Dog mags with mine, they work fine. I'm sure the CMMG mags will work fine, too. I don't think M&P15/22 mags work but I'm not totally sure on that one.

2. Any old upper will work. I also used a lightweight one without the ejection port door (Aero I think) without an issues.

3. I read a lot of mixed opinions on the charging handle but I had an standard one laying around so I figured I may as well try it before buying another one. 1000s of rounds later it's been working fine, no malfunctions.

I built mine with an ALG 8" handguard and Griffin Checkmate can with their little mini 3 lug mount, it's one of the most fun guns I own, I wish I had built this upper sooner!

Thanks for answering my questions. Appreciate it.