Editor's Note: This is a two-part article. Part 1 can be found here!
When we left off, we had a Remington 700 SPS in .308 Winchester. For what it was, I was satisfied but not impressed. Now it's time to beef it up and turn it into something fun. As stated in the previous article, we're going in a "sniper" inspired direction. What better chassis to choose than the MDT ESS or Elite Sniper System?
Step one was to eliminate the flimsy Hogue stock that came with the SPS. It had a short length of pull, was very uncomfortable, and had a ton of barrel contact. While the barreled action was removed, I decided to thread the muzzle and bolt handle. An MDT Elite Muzzle Brake and Badger Ordnance Tactical Bolt Knob were spun on, respectively.
ADDING A CHASSIS SYSTEM
To satisfy my curiosity, I dropped the barreled action into the chassis and made a trip to the range. I was looking to see if dropping the barreled action into the chassis would be enough to make the rifle shoot better. It was an MOA shooter before; I wasn't necessarily expecting that to shrink much. The expected improvement was achieved: comfort. The effect of the adjustable length-of-pull and cheek comb cannot be understated. That, along with the grip angle of the MDT Vertical Grip Elite, made shooting in the prone a far more enjoyable experience. The muzzle brake also made a noticeable difference in recoil control.
Not bad, but I knew the rifle was capable of more, especially with a new barrel.
The groups were all in the 0.8" – 1.2" mark again with Berger and Federal Factory ammo, essentially the same as before. For a factory barrel, that is definitely in the acceptable range. It's time to make this rifle into a shooter.
SWAPPING OUT THE BARREL
The true inspiration for this project is the Marine Corps M40A6. As an Army vet, I can 100% say the USMC had the more attractive sniper rifles (until the Mk22). While the RACS is neat and looks pretty cool, acquiring one will cost you your kidney and life savings. The MDT ESS is more aesthetically pleasing and modular. All that to say: this isn't a clone, only inspired by the M40A6.
So now for barrel work. I decided to use International Barrels. Naturally, due to the inspiration, I went with an M40/M24 profile barrel with a 1:10" twist. I will not go deep on machining the breech side, as it is a standard Remington 700. Things got interesting when I turned my attention to the muzzle. First, the barrel was cut to 20 inches. The brake used was the Surefire MB762SSAL/RE, exactly what was used on the M40A5/A6. It's a piece of leprechaun's gold these days, but I was able to source one.
Typically you only turn the first 0.625" of the barrel for the threads. This brake requires 2.150" of the barrel behind the threads to be turned down to 0.775" for the sleeve of the brake to fit over before the threads. Once the long tenon is turned to size, the threads get cut. Time to test fit the brake. Here you could time it on the lathe or wait and time it with shims. At this point, I didn't have the top of the barrel marked, so I had to time it later with shims. The rest of the brake installation is the same as every other non-self-timing brake.
Lastly, we spun the barrel into the action, torqued it down, and verified headspace. I could have left it as that, but I'm not too fond of unfinished stainless barrels. I sprayed it with Aluma Hyde in Magpul FDE to match the chassis.
THE FINISHED RIFLE
Full Specification of the finished Rifle:
- Action– Remington 700 Short Action
- Trigger- Stock 700 trigger
- Brake- Surefire MB762SSAL/RE
- Barrel- 20" International Barrels M40/M24 Profile, 1:10" twist, .308 Win.
- Chassis- MDT ESS with MDT Vertical Grip Elite
- Bipod- Harris 6" -9"
- Optic- Schmidt & Bender PM II 3-20x50 (Hawkins Rings, Nightforce Base)
I spoke to some friends "in the know" about what's doctrine for acceptable accuracy for the M40A6. Without being specific, they all said sub-MOA was expected and sub ¾ MOA was desired.
Also, something to note is the effective range with the 20" is 800m or roughly 850 yards. Now that we know what expected performance it's time to work up a load and really stretch the legs of this rifle which I will cover in the next article. Thank you for reading.
BUILD RESOURCES FROM MDT
- Upgrading the Bergara B14
- Building a Custom Bergara B14 for Competition
- Building a 308 Tikka Rifle
- Building A Training Rifle - Part1 and Part 2
- Building a General Purpose 300 Win Mag Rifle
- Building a 6mm GT for Competition
- Re-building a 308 Winchester from a Remington 700 SPS Tactical
ABOUT THE AUTHOR
William Maxwell served in the United States Army. After returning from his first deployment in 2015, he started building firearms and focused heavily on pistol and carbine training. In 2018 he fell into the rabbit hole of precision rifle shooting. He spends his free time competing, reloading, editing digital content, and writing. He can be reached via Instagram @maddmaxxguns.