[smp4616]

bought an M1A a couple months ago, usually shoot m1 garand, wanted something with a newer barrel and action, my garand is a '45 action and '54 barrel. was shooting 97-98 in prone with sling at 200 yards cmp adjusted targets, thought a newer rifle would bring that up. unfortunately I have had absolutely no luck with the m1a, I went shooting once, thought it shot like crap, so I loaded some rounds for it, copied the military loading with 4895 powder, took it out, still shot like crap, seemed to shoot a little better without the sling, so I checked it out and found the following.

-the stamped steel piece that holds the front stock to the barrel was loose and could be moved easily.

-the rear sight aperture could be moved +-1/16" in the windage.

-I realized the whole gas block could be moved by hand because the front sight post was threaded to vertical but wasn't exerting any pressure against the gas block (therefore the front sight could float around as the only thing holding it vertical was the gas plug).

my fixes were as follows:

weld edge of aperture rack, then regrind to fit track. -seemed to work because the rear sight is now stiff and can't be moved side to side unless adjusted so

machine .022" shim to positively clamp gas block when front sight post is in vertical position

machine .022" shim to prevent gas block plug from bending barrel against front sight post

results were not promising, it was still all over the place and even worse with a sling, in prone I checked where the sling was pulling and in this instance, it was pulling basically straight back and slightly down.

I'm completely at a loss at this point, I think this rifle should at least be able to go toe to toe with a 70 year old M1

 

[Buelligan]

The .022" shim between the gas lock and gas cylinder changed the timing of the gas piston inside the cylinder. This is probably not a good thing. A much thinner shim should be used behind the front band (the stamped steel piece) and shoulder of the barrel so the gas lock just starts making contact at the 5 o'clock position. Any more lock-up is detrimental to accuracy. You can also peen the slots on the barrel the gas cylinder slides onto to keep the assembly rotationally secure. Make sure the only contact between the front band and ferrule (the metal part at the end of the stock) is at the bottom lip. Also check the alignment and tightness of the op-rod guide. These sometimes have a tendency to lose their grip on the barrel and they can shift. There are more things to check, but these are pretty much the fundamentals. I suggest watching the videos on youtube that outline these procedures pretty clearly.

It sounds like you have a gas lock sight? If accuracy is your goal, use a flash suppressor sight, it'll give you maximum sight radius with whatever barrel length unless it's a SOCOM.

 

[Capona]

You have too many variables going. How new is the rifle? W
If it's worse with sling, then you are introducing stock variables into the equation.
Eliminate slinging up and work from sand bags on a solid bench until you establish your baseline accuracy. Work with match ammo until you know what to expect.
Define your craps results specific to Moa.

bought an M1A a couple months ago, usually shoot m1 garand, wanted something with a newer barrel and action, my garand is a '45 action and '54 barrel. was shooting 97-98 in prone with sling at 200 yards cmp adjusted targets, thought a newer rifle would bring that up. unfortunately I have had absolutely no luck with the m1a, I went shooting once, thought it shot like crap, so I loaded some rounds for it, copied the military loading with 4895 powder, took it out, still shot like crap, seemed to shoot a little better without the sling, so I checked it out and found the following.

-the stamped steel piece that holds the front stock to the barrel was loose and could be moved easily.

-the rear sight aperture could be moved +-1/16" in the windage.

-I realized the whole gas block could be moved by hand because the front sight post was threaded to vertical but wasn't exerting any pressure against the gas block (therefore the front sight could float around as the only thing holding it vertical was the gas plug).

my fixes were as follows:

weld edge of aperture rack, then regrind to fit track. -seemed to work because the rear sight is now stiff and can't be moved side to side unless adjusted so

machine .022" shim to positively clamp gas block when front sight post is in vertical position

machine .022" shim to prevent gas block plug from bending barrel against front sight post

results were not promising, it was still all over the place and even worse with a sling, in prone I checked where the sling was pulling and in this instance, it was pulling basically straight back and slightly down.

I'm completely at a loss at this point, I think this rifle should at least be able to go toe to toe with a 70 year old M1

 

[mike in pa]

Follow capona's recommendations, a great place to start.

 

[smp4616]

I'll reshim against the front band and shoot off some bags and post results. as far as defining "crap" in terms of moa, I'd say it's shooting about 25moa measured from extreme poi's, if you factor human error into that, and subtract the maybe 3moa from unsupported prone position, it's still in the range of... well, crap.

 

[dwight55]

Follow capona's recommendations, a great place to start.

I had that very same situation with an AR a couple of decades ago. Could not get any reasonable accuracy out of it with a sling.

Found out my sling technique was the problem, . . . too much torque here, too little there, . . . thing shot worse than an open bore scattergun.

Few people realize the sling CAN BE detrimental to accuracy if used incorrectly.

May God bless,
Dwight

 

[BLACKTAIL 8541]

Try some shims at the front of the receiver to create a fulcrum to increase draw pressure.
M1A's need it to have any hope of repeatable accuracy.

 

[KurtC]

On a service rifle, the front sight should is on the flash suppressor, not on the gas lock. If yours is on the gas lock, it is an aftermarket item. Your sight radius is now 6 inches shorter than designed. This will affect your accuracy.

M1A commercial barrels have a throat and twist intended for 168 grain match bullets. Trying to duplicate machine gun fodder isn't giving the barrel the justice it deserves.

 

[dwight55]

On a service rifle, the front sight should is on the flash suppressor, not on the gas lock. If yours is on the gas lock, it is an aftermarket item. Your sight radius is now 6 inches shorter than designed. This will affect your accuracy.

M1A commercial barrels have a throat and twist intended for 168 grain match bullets. Trying to duplicate machine gun fodder isn't giving the barrel the justice it deserves.

KurtC, . . . just a quick question, . . . is that ALL M1A's (assuming you mean only those produced by Springfield), . . . and for how long has that been the standard???

Some time ago I read that anything seriously above 155 grain was detrimental to the action as it put more force on it than the original design called for.

Just curious, . . . as I am not a super shooter, . . . and anything I can find that may help my accuracy, . . . I'm all for it.

Thanks, may God bless,
Dwight

 

[Capona]

Anything above 180 is detrimental to your oprod. Applies to all m1a : m14
With 168 match (SMK) generally being best for accuracy although I get good results with 175 match as well.
145-175 is fine


The difference between good match ammo, and plinking ammo at 100 yards is 1.2 moa for good match, vs 3-4 inches for shooting fodder. You decide what you prefer to shoot. That's scoped, sandbags, high performance JAE stock. Ymmv.

KurtC, . . . just a quick question, . . . is that ALL M1A's (assuming you mean only those produced by Springfield), . . . and for how long has that been the standard???

Some time ago I read that anything seriously above 155 grain was detrimental to the action as it put more force on it than the original design called for.

Just curious, . . . as I am not a super shooter, . . . and anything I can find that may help my accuracy, . . . I'm all for it.

Thanks, may God bless,
Dwight

 

[Capona]

On a service rifle, the front sight should is on the flash suppressor, not on the gas lock. If yours is on the gas lock, it is an aftermarket item. Your sight radius is now 6 inches shorter than designed. This will affect your accuracy.

This all sounds strange to me. why would someone attach a front site to the gas cylinder instead of the barrel? Why would someone sell such a product or what would be the purpose of changing the intended design?

 

[tonyben]

Read this thread...

http://m14forum.com/reference/73926-m14-m1a-health-check.html

And check out my videos here...
https://www.youtube.com/user/tonyben3/videos

Load all the videos on the page and check out the cleaning, lubrication, gas cylinder shimming and inspection videos that I've posted over the last 5 years. Your answers lie somewhere in there.

Tony.

 

[tonyben]

This all sounds strange to me. why would someone attach a front site to the gas cylinder instead of the barrel? Why would someone sell such a product or what would be the purpose of changing the intended design?

Some people put on direct-connect flash hiders that have no front sights, or they install suppressors (silencers) which require a thread adapter to work on our M14's. Most of the time, this will require that you relocate your front sight to the gas lock or use optics exclusively. That's why we have gas lock front sights. They usually require taller front sights to work at 100 yards.

Tony.

 

[Capona]

Thanks for that info Tony. I need to move to a state that allows suppression.

 

[smp4616]

I think the front sight is on the gas lock because of NYS restrictions on having a threaded muzzle. I bought the rifle from a local shop that ordered is [supposedly] from springfield as nys compliant... though my suspicions based on the awful rear sight and being put together in what I feel is a questionable manner, it makes me think someone other than springfield put it together.

 

[KurtC]

KurtC, . . . just a quick question, . . . is that ALL M1A's (assuming you mean only those produced by Springfield), . . . and for how long has that been the standard???

Some time ago I read that anything seriously above 155 grain was detrimental to the action as it put more force on it than the original design called for.

Just curious, . . . as I am not a super shooter, . . . and anything I can find that may help my accuracy, . . . I'm all for it.

Thanks, may God bless,
Dwight

Use of the 173 grain bullet in the M14 goes back to Vietnam (M118) and use of the 168 grain bullet goes back to the 1990's (M852). Most military and commercial match barrels are throated long for such bullets and have a faster twist (1/10 or 1/11). Original M14 chrome lined barrels are designed for the 150 grain M80 bullet, having a 1/12 twist.

The weight of bullet has nothing to do with damaging the oprod. It is the amount and type of powder that is used to bring such bullet up to a desired velocity. Folks shoot 220 grain bullets at subsonic velocities with no damage to the rifle. As long as you keep your port pressure at about the 12k PSI level, you are fine. If you use a lot of slow burning powder to get max velocity out of a heavy bullet, you need to start considering a way to lower the port pressure, such as a ported and overbored gas plug. Otherwise you will eventually bend or crack your oprod.

 

[Buelligan]

I still have some 180 grain Winchesters I tried to use 19 years ago, but it felt like they were hammering the op-rod into the receiver. I still have them, I figure if I ever have to use them, I'll turn the spindle valve off.

 

[wiz1997]

I think the front sight is on the gas lock because of NYS restrictions on having a threaded muzzle. I bought the rifle from a local shop that ordered is [supposedly] from springfield as nys compliant... though my suspicions based on the awful rear sight and being put together in what I feel is a questionable manner, it makes me think someone other than springfield put it together.

Give SA a call.

Provide the serial number and they can tell you how it left the factory.

 

[BrokenVet]

Was the rifle bought new, used?

 

[Thedutchman]

Have you been watching the VSO gun channel on YouTube...lol.