BCM SPR Mk 12 Mod Numbers ?

AR/M4 AR Technical Discussion
1

I’m thinking I’d like to build another AR using an BCM SPR Mk 12 upper.

Looking at the different Mod numbers, (0-4, R,U,X, etc), the only real difference I can see is the choice of rail. If I’m missing something important here, could somebody please explain?

2

Here is a pretty helpful resource:
http://www.mk12.net/

and this forum will be more catered to your questions regarding the Mk 12 and similarly-purposed rifles:
https://www.m4carbine.net/forumdisplay.php?f=172

3

The only differences between the BCM MK12’s are the rails and whether the barrel is ion-bonded or not. Some of the PRI railed options also have that flip up front sight gas-block riff-raff.

Basically just pick a rail and then pick ionbond or not. The overly complex model numbers don’t mean anything.

I’ve got the MK12 upper w/ DD 14’’ Lite-Rail. Not sure what ModXYZ234523 whatever the hell that is. It shoots lights out and all the forward rail space you can get with a bipod, the better. It’s a bit heavy but balances how I like it to.

4

Thanks. That’s what I was looking for.

5

If you are looking to do a MK12 I would give Monty at Centurion a HARD look. His MK12’s are second to none. Nothing against BCM, but in this case I think Centurion is the better option.