May 19th, 2008

Reviving a Remington 700

Gunsmith Nat Lambeth, nlambeth [at], recently had a client bring in a Custom-Shop Remington that wouldn’t even hold one Minute of Angle (MOA) at 100 yards. Nat was able to correct flaws in the factory action and then fit a new barrel. Remarkably, after action truing and barrel replacement, the gun shot like a house on fire. After working his magic, Nat shot a 0.111″ 5-shot group with the gun.

Nat tells us: “I had a customer bring in a Remington 700. This rifle was supposed to have been from the custom shop. It was a stainless model 700 with a 5R Mil Spec barrel in a HS Precision stock. The customer paid a premium price for this rifle. The customer complained the rifle ‘won’t shoot groups under 1.5″ at 100 yards’, and he wanted a new barrel. He had 400 rounds down the tube. The barrel looked to be in good shape with maybe a scratch 8 inches from the muzzle.

Blue-Printing the Receiver
I removed the barrel from the receiver and looked at the internal bolt lug engagement surfaces. Only one lug seemed to be contacting. I put the bolt in a V-Block and measured the rearward bolt lug surfaces. The right or bottom lug had .019″ more reaward surface than the left or upper lug. This would have taken me two days to lap out so I set up the bolt in a truing jig and turned the bolt .020. I then put the action in a action truing jig and machined the inside lug surfaces until I got one even surface. I lapped the lugs until I had 80% bi-lateral contact, then re-faced the bolt and action face.

New Broughton Barrel
I dialed in a new 26″ Broughton 1:10, 5C barrel. It was indicated on both ends until a .0001″ indicator needle was not moving. The barrel was turned, threaded, and chambered in the same setup using thinbit tooling, a PT&G 95 Palma reamer with a .3004 bushing. The chamber was cut within .0015″ with a Lambeth/Kiff Micrometer Adjustable Reamer Stop. The factory recoil lug was replaced with a precision-ground lug.

The barrel was removed from the lathe and the muzzle was cut 1.250 shorter in a bandsaw. The barrel was re-mounted in the lathe and the muzzle dialed in the steady rest. The crown was faced with a piloted, PT&G facing tool then faced with a piloted, 79° counter bore .100″.

Stock Work
The rifle stock was re-inletted and glassed in for two inches. Then the barrel free-floated.

A Tack-Driver is Born
I thoroughly prepped 22 pieces of used 308 Federal Gold match brass, which were then loaded with 42.5 grains of H4895, CCI BR2 primers, and Hornady 168 HPBT bullets. After cleaning the barrel, I fired one test round with no problems and cleaned the barrel again. I then installed a Leupold 6.5-20AO scope in Farrell bases and rings. I bore-sighted the rifle by eye with the bolt removed at 50 yards.

After some sighters to set Point of Aim, I sat down and did 5 shots for record at 100 yards. Those five shots went into one ragged hole. (See Target Below — this editor measures the group as 0.111″ center to center using OnTarget Software.) Another customer who was there at the range, then shot a 5-shot group that went into 0.312″. That’s an 0.2115″ average for the two groups. I then was able to shoot a couple more groups in the ‘teens.”

Nat proved that attention to detail DOES make a difference, and that truing an action, improving the bedding, and fitting a superior barrel can make a HUGE difference in accuracy. Now, mind you, we’re not suggesting that you can take a factory .308 and make it into a gun that will win the Super Shoot. Nat’s 0.111″ group was exceptional. Still this demonstrates that major gains can be had by action blue-printing combined with bedding work and a new barrel.

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