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View Full Version : AR-10 vs M-1A/M-14: Convince me…


Chuck Dye
October 7, 2006, 07:28 PM
My particular version of material lust leads to a slow approach to acquisition. I am getting closer to a military type .308/7.62 NATO semi-auto. My inclination is toward the full boat Fulton Armory rifle.

I would appreciate input from those who have extensive experience with both the AR-10 and M1A/M-14’s. I am particularly interested in the piston and op-rod versus direct gas impingement difference.

JIH
October 8, 2006, 12:07 PM
Theoretically, the AR-10 will be more accurate, because it has fewer moving parts. You only have the bolt moving back and forth. If the barrel is free floated, no external forces act on the barrel, and it's free to "do its thing."

The M14/M1A has an operating rod that's moving around and theoretically jerks around the rifle and barrel given its mass, which is relatively higher than that of just the bolt in the AR. Furthermore, the gas system and operating rod are attached to the barrel, preventing free-floating.

Theoretically, the M1A will be more "clean" as the gas used to work the action should not enter the firing chamber (it impinges up on the "front" of the op rod), whereas with the AR-10, the gas will enter by design in order to cycle the bolt.

In real life, for the average joe, the difference is meaningless. Get what feels right to you. If you're going to clean regularly -- like you should anyway -- you're not going to see a difference in cleanliness and unless you're shooting out to 1,000 meters and you're shooting ammuntion from loaded by David Tubb, himself, the accuracy difference won't show up, either.

ETA: I am exaggerating a bit. But not by a lot.

nbkky71
October 8, 2006, 07:20 PM
I do love the M1A and have been shooting one for years. It's the gun that I first started shooting NRA highpower with.

However, I think that you'll get the most bang-for-the-buck out of an AR10. The M1A/M14 can be an accurate platform, but it does take some work to wring the most accuracy out of it. There's a reason the Fulton Peerless match rifle costs $2800.

What are your plans for the rifle: target shooting or competition?

ITEOTWAWKI
October 8, 2006, 07:35 PM
Why can't someone want one for the zombie factor? I've kinda been thinking an aweful lot about a 20' Flattop AR10 for that very reason. Only problem is that I can only find DPMS ones when I really want an Armalite.

Unclenick
October 8, 2006, 08:02 PM
The gas tube on the AR is anchored to the barrel, too, so you don't get away from that factor completely. However, if you get a floating hand guard, the inherent accuracy of the AR is better. The bedding in the M14 can be finnicky and can get oil in it and have to be cleaned and gets beat up and eventually needs to be redone. The M14 is normally bedded with the barrel angled up just enough so the forestock pulls down on it to reduce vibration. This is supposed to make it a little less sensitive to different loads, but if it does, I haven't noticed. I still have to tune loads for it, same as my mouse gun. If made of wood, the stock's pressure in pulling the barrel down can alter with long-term exposure to moisture. It will alter some with temperature regardless of the composition, and you may find the sight setting changing a click or two during a long range match from that.

The gas cylinder in the M14 is a clever design that closes off the gas port after it gets underway, thus allowing it to work with a wide variety of load pressures. The M14 op-rod works on only right side of the gun. This is an assymetric lateral pressure which should limit how tightly it groups left to right, but half MOA can still be done. The AR recoil assymetry is on the vertical plane, and so is simply part of vertical recoil moment which is there anyway.

The M14 shoots really well when properly cared for, but has more things to keep an eye on. The AR should be possible to shoot more tightly with. In match shooting, however, which one best suits your body and eyesight is likely going to be more important that the accuracy difference.

Nick