308 DMR Build

[Jerry R]

I am putting together a 308 DMR. Not called that because I ever was, or ever could be, called a Designated Marksman, but because of the desired results I hope to achieve in the quality, and accuracy of the build.

Parts are starting to trickle in, and I will update this thread with photos of parts, and of the assembly as it progresses.

The parts that have been ordered:

Ascend Armory Match Billet Receiver Set – 7075
Rainier Arms AR10 Switch Keymod Rail .308 – 17”
Rainier Arms Ultramatch Mod2 .308 Barrel .800 Gas Block TiN Extension Fluted – 18”
Rainier Arms Adjustable Bas Block Solid Bleed Off .800 Black
I asked Rainier to pin the gas block for me – I do not have a jig for that.
SI UDC Ultimate Dust Cover for .308
Rainier Arms .308 NiB BCG DPMS SR-25 Pattern
Geissele Super Charging Handle
CMC AR-15/AR10 Lantac E-CT1 Single Stage Upgrade Trigger – Curved
Ascend Armory Titanium 50 Degree Short Throw Ambi-Safety
LUTH-AR .308 Rifle Length Buffer Tube Kit (includes Rifle Length Spring and Rifle Buffer)
MagPul PRS Gen3 Stock
BCM Gunfighter Grip Mod-1
AAC Blackout 51T Flash Hider / Suppressor Mount (for use with the 762-SD)
BoBro Precision Optic Mount – 30mm 20MOA

For initial accuracy testing I will pull the Leupold 8.5x25 x 50 AO Target scope off the .243 Prairie Dog rifle (Remington 40XB KS). This scope was sent to Premier Reticle in 1999 for conversion to a 25 to 50 variable. They did an awesome job, but I’m not sure I am a fan of that much magnification. In both trips to Montana, the mirage was VERY noticeable and the high end of the scope was rarely used. However, I will be shooting off a very stable bench at 100 yards, and I think the scope will help my poor old eyes wring out the last drop of accuracy that I can squeeze from the build. This may, or may not, be the final optic solution for this build. I hope to go back to Montana at least once more.

I selected the CMC Curved Trigger because currently I do not have a flat trigger. I may get one in the future and drop it into one of the guns with a “mil-spec” just to see if I like it. But I wanted to build this DMR with a fire-control setup I am very comfortable with, and that means a curved trigger.

I selected the Ascend Armory Receiver Set because of certain unique features and controls. It is an ambidextrous lower receiver, and they have stated they will upgrade the lower (for free) with their ambi-mag release when it is available. The matched set also looks good.

The barrel was selected because I have other Rainier Ultramatch barrels and I am extremely pleased with their accuracy off the bench. If a rifle is accurate off the bench, it will be accurate in the field – in the hands of a rifleman (apologies to the many ladies that are excellent shooters). The barrel has a “.308 Rainier Match Chamber”. Quote from the Rainier web site:

The Rainier Match Chamber is a modified .308 WIN-7.62 NATO chamber to produce ultimate reliability and accuracy shooting both the 7.62 NATO & .308 WIN rounds.

It is (extremely) unlikely that I will ever hump a DMR in the boonies with a spotter and kit, but as Townsend Whelen once said, “Only accurate rifles are interesting.”

I thought about putting another BattleComp 51.30 on this build, but I have a never used AAC 308 mount in the parts box. SilencerCo shipped it with the 762-SD and I did not know it was a package deal, so I bought a mount when I bought the can. My loss then, my gain now.