Differences between Mk12Mod1 uppers

[Cesiumsponge]

How authentic do you want to go?

I got mine put together by MSTN with all Mk12 parts and build except the barrel. Wes specs a Noveske "Mk12 Mod 2" contour SPR barrel which has 3-groove/land rifling. It is not their commercially offered SPR barrel which is polygonal. At the time, Monty at Centurion was just starting up (still had the old website) and there was an estimated 6-8 month wait and I couldn't wait. I even went with the original set screwing on the gas block.

If I had the extra money for another project, I'd go Centurion for the full authenticity (except maybe opt for a pinned gas block) so I could compare the original Compass Lake barrel with Noveske's offering. Any of the top notch barrels should give top-notch performance today. The Mk12 design isn't a spring chicken and it comes down to how authentic you want to get.

Heck, most people opt for the pinned gas block and that isn't original (they were set screwed). I might take mine and get it pinned as well. Lots of folks have taken the SPR concept and updated the components with modern production parts to tailor their tastes and they're very happy. You're limited on optics if you want to do a true clone build though the newer contract Nightforce issued scopes are very nice. Some people have a deep hatred for ARMS mounts as well, which are used on the original. I went with laRue and Seekins.

I'd be more worried about where to find the hot-loaded Mk262 ammo. I still haven't found any so I've settled on SSA's 77gr OTM loads.

[mstennes]

How authentic do you want to go?

I got mine put together by MSTN with all Mk12 parts and build except the barrel. Wes specs a Noveske "Mk12 Mod 2" contour SPR barrel which has 3-groove/land rifling. It is not their commercially offered SPR barrel which is polygonal. At the time, Monty at Centurion was just starting up (still had the old website) and there was an estimated 6-8 month wait and I couldn't wait. I even went with the original set screwing on the gas block.

If I had the extra money for another project, I'd go Centurion for the full authenticity (except maybe opt for a pinned gas block) so I could compare the original Compass Lake barrel with Noveske's offering. Any of the top notch barrels should give top-notch performance today. The Mk12 design isn't a spring chicken and it comes down to how authentic you want to get.

Heck, most people opt for the pinned gas block and that isn't original (they were set screwed). I might take mine and get it pinned as well. Lots of folks have taken the SPR concept and updated the components with modern production parts to tailor their tastes and they're very happy. You're limited on optics if you want to do a true clone build though the newer contract Nightforce issued scopes are very nice. Some people have a deep hatred for ARMS mounts as well, which are used on the original. I went with laRue and Seekins.

I'd be more worried about where to find the hot-loaded Mk262 ammo. I still haven't found any so I've settled on SSA's 77gr OTM loads.

Gun Broker, ARFCOM's EE, but wait for it, Blackhills is producing M262 for the civilian market now!!!
http://blackhillsammo.wordpress.com/...-commercially/

[BaileyMoto]

On a side note, I think HighCaliberSales is actually slightly cheaper than Centurion as well (not by much). I know HCS uses the Douglass Premium SS barrels, I assume Centurion uses the same, even though they list them as "Centurion Arms" barrels.

[Cesiumsponge]

Gun Broker, ARFCOM's EE, but wait for it, Blackhills is producing M262 for the civilian market now!!!
http://blackhillsammo.wordpress.com/...-commercially/

I actually found this out shortly after I posted that message by Googling out of curiosity to see if things had changed and sourced 500 rounds in the new civilian packaging. It's trickling in and I'm not sure how long it'll last. Demand will probably outweigh supply once words spreads around. It's nice to see the press release state they sub-MOA with a 10-round groups. No one-hole groups! This 50 grain TSX is also interesting. I must look into it.

Monty at Centurion is using the contract Compass Lake Engineering turned Douglass barrels when I inquired back when he had his old website and was only offering the Mk12 and Recce. I assume it still is. I'm not sure if the HCS barrels are processed through the same hands. The info on their site seems to suggest it.

[BaileyMoto]

I actually found this out shortly after I posted that message by Googling out of curiosity to see if things had changed and sourced 500 rounds in the new civilian packaging. It's trickling in and I'm not sure how long it'll last. Demand will probably outweigh supply once words spreads around. It's nice to see the press release state they sub-MOA with a 10-round groups. No one-hole groups! This 50 grain TSX is also interesting. I must look into it.

Monty at Centurion is using the contract Compass Lake Engineering turned Douglass barrels when I inquired back when he had his old website and was only offering the Mk12 and Recce. I assume it still is. I'm not sure if the HCS barrels are processed through the same hands. The info on their site seems to suggest it.

How is this different from the Blackhills SMK 77gr ammo they have had on the market for some time now?

[Cesiumsponge]

The 77gr SMK red or blue box Black Hills stuff is labeled .223 so it's loaded to SAAMI spec. Mk262 chronos about 100-150fps faster as it's loaded to NATO spec. I'm not sure if anyone has worked up a successful load yet, out of my area of knowledge. My ballisticard for the Mk262/AA53 load says its 2740fps @ 60F out of the SPR.

I am not certain if the .223 stuff is cannelured but the Mk262 is. The SSA version is also cannelured and marked as 2,750fps from a 16" barrel. I am not sure what the velocity would be out of an 18".

BHA's blog mentions "Both loads feature military specification brass, sealed military spec primers, temperature-stable military propellant with flash suppressant and are loaded to U.S. 5.56mm pressure limits. " so the 5.56mm version will survive more environmental extremes.

[Birddog1911]

Kevin at High Caliber will treat you very well. He does a great job with his Mk12.

I'm also running the Geissele SSA-E trigger in mine, and I really am happy with it.

The only way that I am deviating from truly authentic with mine is going with a LaRue LT-104 mount, and the NXS 2.5-10x32. That said, I do believe that is the most recent scope, and I've heard from someone currently over there that some of the Navy guys are swapping out their ARMS rings for the LT-104 mount, so I may be alright!

[mstennes]

I actually found this out shortly after I posted that message by Googling out of curiosity to see if things had changed and sourced 500 rounds in the new civilian packaging. It's trickling in and I'm not sure how long it'll last. Demand will probably outweigh supply once words spreads around. It's nice to see the press release state they sub-MOA with a 10-round groups. No one-hole groups! This 50 grain TSX is also interesting. I must look into it.

Monty at Centurion is using the contract Compass Lake Engineering turned Douglass barrels when I inquired back when he had his old website and was only offering the Mk12 and Recce. I assume it still is. I'm not sure if the HCS barrels are processed through the same hands. The info on their site seems to suggest it.

I think you will be able to find it, allot of people just wont shell out what it goes for when they can buy other ammo much cheaper.

[BaileyMoto]

Kevin at High Caliber will treat you very well. He does a great job with his Mk12.

I'm also running the Geissele SSA-E trigger in mine, and I really am happy with it.

The only way that I am deviating from truly authentic with mine is going with a LaRue LT-104 mount, and the NXS 2.5-10x32. That said, I do believe that is the most recent scope, and I've heard from someone currently over there that some of the Navy guys are swapping out their ARMS rings for the LT-104 mount, so I may be alright!

The ones being outfitted in the field are the 2.5-10x24 model I believe. I have seen only one issued rifle with this scope mounted, but it was state side. As a purist, I agree with you. I deviated with my optics and also decided to go with the LMT sopmod stock over the a2 (tho i understand some have been spotted in the field with this stock.....(just repeating rumors)

[dangerdan]

Marines still have the Leupold MR/T 2.5-8x36 scope