Well I have started my Mk12Mod1 build, something that I have wanted to do for a long time but never had the funding for.
Well I got me a second job solely for guns purchases and I am not cutting any corners on this one. So I started with in my mind is the best lower for an SPR build with its superb trigger and ambi everything: The Knights SR-15 lower.
Purchased from Kevin at High Caliber Sales this thing is sweet.
More to follow when I get my Mod 1 upper from Kevin shortly.
Good luck! Building the right ar15 the first time without skimping too much will make you happy in the long run. What are those extra levers around the magazine catch/release on both sides?
Ambi mag and bolt releases.
Maybe I didnt skimp but Id like to change a few things on my 10.5" SBR. But then it wouldnt be a Mk18 clone.
My Mk12 Mod 1 is on a KAC SR-15 lower and I could not be happier. Are you going strict clone build or are you allowing some leeway? I can tell you one thing, the end result is a really nice shooting and looking rifle:
Trying to stay strict complete with Ops 12th can. Doing High Calibers Mk12Mod1 upper and it looks pretty darn close.
You mind posting or PM’ing yor setup?
You know if you got a cantilever mount (LaRue, KAC, ADM, Bobro) you could get your scope mounted all on just the actual receiver? Generally bridging the gap is not a good idea…
But Id imagine judging from the rest of the parts he’s trying to stay with the ARMS mounts due to authenticity.
Im still on the fence about the scope and mount. The rest will be spot on.
Here is mine:
Upper:
Centurion Mk12 barrel
KAC FF RAS
KAC irons
KAC Bipod mount and Harris BRM-S
LaRue SPR 1.5
SB 3-12x50 w/ Gen II mil dot and MTC turrets
Colt BCG
BCM Gunfighter Mod 3
Ops Inc Collar
Smith Enterprise Mk12 Vortex F/H (threaded for Ops Inc can)
Lower:
LMT Defender
Geissele DMR trigger
Magpul UBR
H Buffer w/ Colt carbine springs
KAC ambi selector
Magpul MOE
Yeah buts its better to have parts that won’t possibly cause zero shift issues than trying to stay authentic.
And thats the part Im hung up on. I love Larues mounts and was thinking about the SPR unit with an IOR Valdata.
I like your setup, in fact I was almost going to go kind of that route.
Love it! The best part is I get to shoot that bitch one day. 
Trying to find the picture: mine is extremely similar to Belmont’s… The Mk12ModX civvy variants can be some ridiculously pretty rifles.
As cool as the Mk12Mod1’s we have as issue guns are, fixed stocks are rough to use with armor, and they’re pretty nose-heavy with 12th cans to patrol with.
BCM Lower
MagPul UBR, MIAD, BAD
Geissele SSA
Centurion Mk12 Barrel
12.0 Lite Rail
OPS Brake/Collar (but for 16th)
PRI GasBuster A1
TROY Front, KAC 600m Rear Sight
Leupold MR/T 2.5-8x36mm
ADM Recon30 Mount
ADM Bipod Adaptor with Harris BRM-S
Yessir, and honestly the picture was taken some time ago when i had just gotten the build finished and was playing with eye relief. Where it is has decent eye relief but you’re right, bridging the gap is not what I want. I have since shifted it back.
M249saw hit it that I am trying to stay authentic to a clone build but I’m getting bored with it.