DD M4 RIS II RAIL W/ 12.5" Barrel?

AR/M4 AR Technical Discussion
1

I have a dd m4(12.25") rail on my middy with 14.5" bcm upper and thinking about getting a 12.5" barrel and a battle comp. Therefore my question is will this work? I’ve done some searching and only found a small amount of info.

Thanks in advance

2

Please clarify a little. You are wanting to swap barrels on the 14.5 upper but keep the same rail?

3

Technically it would work, but the battle comp will be partially covered by the rail - not ideal for shooting a comp IMO. You need around a 13.5" barrel for the muzzle device to be clear of the rail.

I had a Colt SBR 14.5", which I cut down to 12.5". For a rail I used a KAC URX mid-length - lease about an inch of barrel exposed and I really like the setup.

4

Thanks. I’ll just build another upper then:) I want a vltor mur anyway

5

The Daniel Defense RIS II GL/SSC is the one you’d want for the 12.5". Unfortunately, it’s not in production.

As already mentioned, the RIS II m4a1 is a little too long. Stick has some pictures of the GL/SSC and a 12.5" barrel out there.

6

I’m in the process of gathering parts for a 12.5" barrel and a DD MK18 RIS II FSP rail to use with my SPR/M4 can. I am also thinking about going 11.5" and using a switch block with the same rail instead of a standard FSP, but I think the rail would be too long for the SPR/M4. I could mill the rail back, but shit I really don’t want to do that to a $350 rail.