Slop between the upper and lower?

[TacBlade]

My CMMG lower and DPMS upper, together do not fit to snug.  There is a lot more play than any of my AR15s.  Besides the JP AR .308 Tension Pin you can get, what else works to tighten that up?  The little red rubber thing-a-ma-jig does not work in a .308 platform? Thanks

[imschur]

Fulton Armory offers the Accu Wedge on their Titan 308 pages.

[TacBlade]

The Accu-Wedge does not work in the .308 AR, at least not in the CMMG lower. Its to big?

[imschur]

I only know it to work with DPMS and clones like Fulton Armory Titan.

[rong10]

Try using a razor blade on the accu-wedge, just shave off material till it fits tightly, it worked for me.I have seen them in a 3 pack for about $5 I believe in Midway, not really sure.

[survivalshop]

My CMMG lower & SI Defence billet upper have a little play also ,as does my DPMS . I don't see it as a problem , some like them tight & believe that makes them better long range shooters .

I have yet to see a test of any sort to prove that claim , but there may be some truth to it or maybe a tighter fit may hinder long range ability.

IMO as long as you have no up & down , front to back ,play at the pins ,it should shoot just fine .

There are also ways to make the pin lugs ,in the upper ,where they fit into the lower , a little tighter.

That may also open another can of worms as far as proper alignment with internal components in the lower receiver.