Folks, for what it's worth - on the M14 Firing Line Public Forum one of the most respected gunsmith/shooters had built an all Winchester M1A (except the receiver). It had a brand new from the tube chrome line Winchester barrel. After the build he was pretty disappointed in it because it was shooting 2 to 3" groups (I assume at 100 yds, his post didn't say).
He said the generally accepted range of torque for the gas plug is 125 to 150 inch lbs. of torque. He had been torquing it to the minumum of 125 inch lbs. The last time he had it apart he torqued it to 150 inch lbs. His groups showed a marked improvement (he didn't say to what size, just that it was much better).
Might be something for you folks with M1A's to try to see if it makes a difference with your rifle.
Can you find the M14 Firing Line Public Forum link to this post?
:)
http://www.m-14forum.com/upload/showthread.php?t=55110
The original poster's alias is Art Luppino. If it's the same guy I'm thinking of he's on an M1A DVD I own and seems to be reasonably competent.
I have heard about consistent torque on the gas plug being an accuracy factor before and am not surprised.
Hmm
Would that work the same with an M-1 Garand ?
I still have lots to learn.
Wade
Couldn't say, but I came across this for the Garand somewhere -
How tight should the Gas plug on an M1 be?
Reports have varied from 120 inch/pounts (10 foot/pounds) to 15 foot/pounds (which is 180 inch/pounds).
Unless you have a wrench, the best way to handle it (according to the field manual), is stand up and place the butt of the rifle between your feet with the trigger guard facing out, grasp the rifle with one hand over the gas cylinder, in front of the handguard, place the combo tool on the nut and then just put your arm into it. Unless you are a powerlifter, you probably won't strip the threads or break anything.
Of course, the best way, according to the 1967 National Match bulletin, is to get the gas cylinder wrench and a torque wrench and tighten it to 15 foot/pounds.
Don't forget to use anti-sieze.
YMMV
Remember, every rifle is a little different than the next one in the rack. What works for one, may not work for another. Last year at the RBC I did something a little "funny" to my M1A and tightened up the groups. The "old timers" said what we did should not have made the groups better, but it did.
The post in the link basically says to try different torque settings within that 120 to 150 in lb range and see if it makes a difference for your rifle. It may or it may not. If your rifle's groups are really disappointing then something like this might make a difference to your rifle.
Now, are two inch groups at 100 yds. acceptable already, for our purposes? Yes. If you can shoot 2 MOA consistently you can work over the AQT and do what you need to do within 500 yds. (once you know what to do for wind and sight/elevation adjustments.)
Then, once you can get the improved results on the AQT, the next step is to make contacts about becoming an IiT or going to an RBC to become an instructor.
Gotcha!
2 MOA will get it done all the way out to 1000 yards, and at that point, the .308/7.62 NATO is about running out of effectiveness. Yes, it is actually past the max effective range of the rifle, but almost to the max effective range of an M60 MG.
Sometimes every little bit helps, and it is worth trying.
Another bit of GOOD info from the M14 firing line public forum.
One of their resident M14 smiths says to use an M1 trigger in your M14. The reason is the M14 trigger pin hole is not completely round (right about a 50% contact between the trigger and pin surfaces) and this results in and increased trigger pin failure rate as compared to an M1 Garand.
The reason the the M1 trigger lasts longer is the hole makes more contact with the firing pin due to it being round.
He says if you have an M14 trigger in your M1A you should replace it with an M1 trigger, but install the M1 sear on the trigger first as the M14 and M1 sears are different.
http://www.m14tfl.com/upload/showthread.php?t=58071
Being a mekanik, I have a little joke for y'all.
What's German for torque?
Gud'n'tite.
Some folks index their gas plug to the gas block once they find a good setting. Not a substitute for a good torque wrench, but fine for field work. Also, antiseize can change actual "torque" on fasteners, increasing the amount of pinch at a setting at the same torque amount, due to loss of friction. BLAHBLAHBLAH. I have heard usually deduct 10% if anti seize is used. Not like I really give a crap, but, now you all know some useless info. Enjoy.
Wade asked earlier if the same information applied to the M1 Garand.
The M1 ports gas directly onto the op-rod piston to cycle the action (some guy named Kalashnikov thought it was a pretty good idea, too).
The M14 ports gas to a piston which cycles the action via op-rod.
In general, info on M1/M14 gas systems will not apply across both platforms.
An additional comment about the M1 vs. M14/M1A gas system is (from what I keep reading) is that the M1 gas system is virtually self cleaning where as the M14/M1A gas system must be cleaned with some regularity based on the the rounds fired, the ammo used and the gas system itself.
This is from stuff I've read on other websites, forums, etc. not personal experience.
If so it means you don't have to tear the M1 out of the stock to clean it as often.
On the other hand, you don't have to 'tear' the M1A 'out of the stock' at all to clean the gas system.
In winter months, I usually don't clean the gas piston and cylinder - not for the whole winter - but in hot humid months, I clean it after shooting, every time...
Fred, you still get to shoot? ;D
Ahh, the good old days...