MK 12 Mod O range report and a lil blood

[WldWldWest]

Took my HCS MK12 Mod O the the range on Sat to try some lighter rounds out of the 1/7 and was pleasently suprised how well it did with 55gr Hornady V Max and after it was said and done they shoot about the same POI as my 77gr. do which is handy as I have several thousand of the 55 grainers squirreled away.
Rifle is a HCS MK 12 Mod O built on a Colt upper reciever
Lower is a Large pin Colt Lower with a very shitty factory trigger. All the rest is as close to a MK12 clone as I'm gonna take it.
As oon as I got the MK12 out It started raining and poured the entire time I was trying to shoot groups.

Then this Hedge Bear rolled out at the 100yd Target, Didnt have to range him!

 

[slowkota]

Re: MK 12 Mod O range report and a lil blood

Nice!

Everytime I see a Mod-0, my wallet sheds a tear!!!

 

[YTALER]

Re: MK 12 Mod O range report and a lil blood

Nice looking rifle. Bad timing for the Hedge Bear !

 

[WldWldWest]

Re: MK 12 Mod O range report and a lil blood

Thanks, I felt kinda bad for the Hedge Bear but...He didnt feel a thing!

 

[2ac]

Re: MK 12 Mod O range report and a lil blood

I picked up a Centurian Arms DMR upper this summer. I believe our rifles share the same barrel. Mine also likes the Nosler CC bullet, it'll put 5 69 grainers into a .4 or so group too. That's with Varget, I'll have to try the 77s again. They weren't too impressive with TAC.

 

[WldWldWest]

Re: MK 12 Mod O range report and a lil blood

I have a HCS Mod 1 that really likes the 77gr. SMK over TAC but doesnt shoot the Noslers all that well with anything I've tried.
My Mod O shoots 77gr SMK's really well over VV140 As well as the Noslers, I get a lilttle better velosity with VV140 but the group opens up a little when I load max.

 

[JelloStorm]

Re: MK 12 Mod O range report and a lil blood

Is that a piston or a DI system?

 

[slowkota]

Re: MK 12 Mod O range report and a lil blood

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JelloStorm</div><div class="ubbcode-body">Is that a piston or a DI system?

</div></div>

99.999% sure it is DI. Its an HCS build.

The gas block is a PRI w/ folding front sight intergrated.

BTW... What the hell is a "hedge bear"??? Looks like a woodchuck to me!

 

[Trigger Hippie]

Re: MK 12 Mod O range report and a lil blood

Nice shootin'. I'll have to try some of that Vihta Vuori powder.

I have an 18" Noveske SS built up in a similar fashion, though sans the PRI tube and (rather nice) block sight.

The Lyman load manual I have lists RL-15 as the most accurate powder for 77s. During load testing I'd often see groups with bullets touching or keyholing that were 0.1 - 0.4 grains apart in charge levels. My current load SMK77 load is 23.5 gn of RL-15 with CCI 500s - well below the max charge levels listed. The 69 grain load I settled on was similar - 24.0 grans of Varget, well below the listed max of 26.something.

Anecdotally a few other AR shooters I've chatted with at the range have mentioned seeing similar results - the most accurate handloads seeming to be well short of max pressure. Wonder if you're getting similar results.

 

[USMC mustang]

Re: MK 12 Mod O range report and a lil blood

I'm also seeing excellent results with mild loads from my 18" Noveske. My go to load for 77gr SMK/Nos CC is 23.5 grains of Varget and for 69gr SMKs it is 24 grs of RE-15. Both are giving me consistent 1/2-3/4 MOA groups.

 

[2ac]

Re: MK 12 Mod O range report and a lil blood

^^^ Same here, about .65 average moa with 24 gr Varget and 69 gr Nosler CC. Sometimes better or worse, depending on me.
Which makes me wonder, what kinda accuracy are people getting with MK262. I know velocity is king for some, but are you hitting what you're aiming at? Are we talking minute of man at 600 yards?

 

[WldWldWest]

Re: MK 12 Mod O range report and a lil blood

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: slowkota</div><div class="ubbcode-body">

BTW... What the hell is a "hedge bear"??? Looks like a woodchuck to me! </div></div>

Just a greasy Ole Groundhog, we call em Hedgebears as not to offend em.

 

[USMC mustang]

Re: MK 12 Mod O range report and a lil blood

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 2ac</div><div class="ubbcode-body">^^^ Same here, about .65 average moa with 24 gr Varget and 69 gr Nosler CC. Sometimes better or worse, depending on me.
Which makes me wonder, what kinda accuracy are people getting with MK262. I know velocity is king for some, but are you hitting what you're aiming at? Are we talking minute of man at 600 yards? </div></div>

MK262 has been pretty accurate in my experience. I've never shot it from a scoped precision rifle but from M4s with an ACOG and NM ARs. When I was shooting with the Parris Island Shooting Team we shot it across the course for a number of matches and it shot extremely well, I remember a Sergeant on the team scored in the high 480s during an EIC match with it.

 

[WldWldWest]

Re: MK 12 Mod O range report and a lil blood

MK 262 Shoots decent outta both my MK12's, Shoots around an Inch or so at 100yds, chrono's at 2750fps. I havent achieved this Velocity with my handloads but I have gotten close. 2725fps with VV140 and SMK's. I tend to shoot it a lil better than the MK 262 but still not sub MOA. Minute of Man at 600...Absolutely.

 

[Ro_Bird]

Re: MK 12 Mod O range report and a lil blood

My experience with MK262 either MOD 0 or MOD 1 is that generally it will hold about 0.5 to 1 MOA out of the MK12's. My last MK12 MOD 0 would hold a solid 1 MOA with MK262 MOD 0 (10 shoot groups) suppressed unsuppressed it didn't care how hot the barrel got. Velocity was 2770fps. I honestly don't know what the round count was before I received it so the barrel may very well have on the way out. My MK12 MOD 1 on the other hand I received new. It now has +2500 down the pipe and as long as will hold I keep the barrel cool it will hold .3 to .5 MOA for 10 rounds with MK262 MOD 1. Velocity has also been running at 2790fps. It kind of seems to me that the SMK's don't seem to do as well as the Nosler's at higher velocities (+2750). But with out being able to shoot MK262 MOD 0 and MOD 1 back to back out of the same gun it's only just a guess.

Interesting that the VMAX's are shoot well. Might have to give that a try some time.