Cenutrion MK12 LINK
Rainier Arms UM Mod2 LINK

Links above to the two I'm thinking. Working on a quasi MK12 build. At first I was all in on the Centurion barrel, but I've been reading some good things about the Rainier Arms barrel that is also $100 less. Any thoughts on the two? I'm not looking for competition shooting, just a one-and-done build that I can enjoy stretching out to some good precision yardage.

Thanks.

I dont have any experience withthose barrels. But i did do a build with a Rainier arms lightweight match barrel. Good but not as good as the ultra match. With the cheapest 62gr green tipaybe 2 or 2.5 moa. With the cheapest 55gr 1.5-2 moa. Cheap AAC 75gr  and 77gr bthp it tightens way up. I am not the best shooter so i still get some 1 or 1.5 groups. But have shot several .75 and smaller. I have not shot it enough to say it is a excellent shooting barrel but i can say for sure it is at least good or very good. I think when i work on my shooting a little even with the cheaper AAC "match" ammo i shoot it will be sub moa all day. I think the Ultra match will be a little better.

When i was doing my build Rainer wouldnt telle what blanks the match and ultra match were. They said the match should be sub moa and the ultra match closer to sub .75 moa. It has taken me a little work but to get that but it appears to be true for me.

I’d like you to meet “the whore of endor” this is a centurion mk12 rifle. I know you asked about the barrel but this has it.

This rifle is my loaner gun when I want to put people on target with minimal effort. It’s easy button accurate and with the current 77gr loads from AAC I’m well under sub moa. The rifle has seen well over 4K rounds and j have yet to clean it. I will add most oil prior to shooting and it just performs.

Get the mk12.

Attached File

Nice, that Mark 3HD, is it the 4-12 or 3-9? How do you like the scope?

I would also recommend Centurion. I borescoped my Mk12 Centurion barrel and its beautiful inside, it looks like they lap their barrels even though they don't advertise it, probably why yours is still accurate after 4k without cleaning. A cheaper barrel with tooling marks would be laden with copper fouling by that point.

I like the scope but wish I had the side focus model. I will probably get that for this rifle. Or an old Leopold patrol.