LWRC REPR MKII UPPER RECEIVER COMPATIBLE WITH A ARMALITE AR-10 LOWER?

[SYTY]

HI this is my first post, My cousin sent me a email today asking if a (LWRC REPR MKII UPPER RECEIVER COMPATIBLE WITH A ARMALITE AR-10 LOWER)?

It looks like it might work but i didn't want to tell him it would. I talked to Stag & they said the Stag 10 uppers will work on a AR-10 A  lower.

Any info would be great 

[Rsquared]

Simple answer is no. The LWRCi is a piston driven system, where the AR-10A is "designed" to be a standard direct impingement system.

If he's already spent the cash on an LWRCi upper, he might as well go the rest of the way and pick up one of their lowers. Keep everything from the same manufacture.

By the way, I've handled a Reaper before, my son owns one. Pretty sweet. LWRCi makes quality stuff.

[SYTY]

No he hasn't bought an upper yet he asked me if i know if it will fit,  So the Repr upper won't fit on the Armarlite lower?, piston & DI gas system should not make a difference just change buffer and spring for piston system like on the AR15s no.

[Rsquared]

I can't say whether or not it would physically fit, cause I've never tried it. You've got to keep in mind that the large frame 308 AR is a different animal than it's small frame counterpart. There's enough confusion just trying to get the many different manufacture's to try and get some kind of standard. They're all out there doing their own thing for the most part. No Milspec on the large frame AR. Which is why we keep seeing cycling issues spring up, as guys come here trying to figure out why their rifle won't run.

[DNP]

Best to keep upper and lower from same manufacturer. Eliminates headaches in any variance there might be in design or tolerance. If an issue does show up, you have one company that will need to correct or replace one part. If you have x matched with y, they’ll each blame the other and you will never sort it out. Stay same brand on receivers, way less trouble. 

[SYTY]

Thanks for the help I'm going to tell my cousin to stay with Armalite set up only.