My M1A Progression

[amprecon]

I bought this Springfield Armory Standard M1A awhile ago and found some surplus M80 ball ammo to shoot through it. I want to use this rifle as an all-around utility rifle for hunting, target shooting and such. Little did I know about M80 ball ammo. The story I got about the 147gr. M80 ball, is that it was intentionally made very slightly under-sized so as to run cooler in machine guns. I don't know if this is the true reason, but the 147gr. M80 ball bullets are physically under-sized. I installed an ARMS #18 mount, which I had to send to S.A. to get installed correctly. I then installed a Nikon 6X42mm Monarch scope on it. I could not group well with it and was concerned about the rifle, the scope, the mount, the ammo, it was printing about 8-10 inches at 100ds. A gentleman at the range came over and inquired about how things were going to which I replied not well. He asked about the ammo and blamed it for 90% of my accuracy problems. So we removed the bullets from some of the M80 ammo and installed some Sierra 168gr match boat tail bullets in their place and the groups shrunk dramatically to about 2-3 inches at 100ds.
I finally received my Sierra bullet order, 1,000 150gr. spbt bullets and changed out about 550 M80 bullets with the Sierra bullets and then back to the range today. The first couple of groups were good with him shooting and then myself shooting. After a target change, we shot again and the grouping stayed about the same but moved. They were up from center, then down from center. What we realized was the grip we were using to steady the rifle on the rest, when we gripped forward on the forearm just forward of the magazine the groups went high. When we gripped the aft end of the stock with our free hand the groups went towards the bottom.
So a bedding of the action is in order and we believe that this should remedy the wandering groupings.
But it's been an interesting ride and I have learned alot. As I have not done any kind of bedding work before this will be another learning experience and I hope it will make a good shooting rifle even better.

 

[lipadj46]

Little did I know about M80 ball ammo. The story I got about the 147gr. M80 ball, is that it was intentionally made very slightly under-sized so as to run cooler in machine guns. I don't know if this is the true reason, but the 147gr. M80 ball bullets are physically under-sized.

Where did you read that? M80 ammo was specifically issued for M14 rifles too, not just M60, M240 etc, machine guns. It is not match or sniper ammo to be sure though.

Sounds like your rifle could benefit from some more pressure on the barrel so if you bed also put a bit of a hump up in the forend to get a little more downward pull on the barrel.

 

[amprecon]

Good suggestion, I think we'll incorporate that "hump" for more support.

 

[Maverick223]

Good suggestion, I think we'll incorporate that "hump" for more support.

Not a bad idea...If I read the article correctly (by the late Mr. Gale McMillan IIRC) I heard of a novel way to do so (never tried it before or bed a rifle so YMMV) using a 5lb (?) weight hung from the front sling swivel to bend the stock down during the bedding process. When the stock as cured you can release the tension, allowing the stock to curve upwards and put a little tension on the barrel. It is similar to the principle used for pretensioned concrete bridge decks.

Now where are the pictures? The title is misleading...thats false advertising and grounds for ban!

 

[lipadj46]

Good suggestion, I think we'll incorporate that "hump" for more support.

It's not for more support the small hump lifts the barrel up a little so the stock ferrule will pull down on it with more pressure. This tension aids in the precision of your rifle. Google "M14 stock bedding" or "M14 glass bedding" for numerous good step by step walkthroughs.

Here is one:

http://www.imageseek.com/m1a/M1A_Bedding/

SAI will do it for a decent price but the shipping will run you around $70 both ways.

 

[Maverick223]

Quality barrels will perform better free floated but poor quality barrel will perform better with a 3 to 5 lb fore end pressure. The reason for this is that
poor quality production barrels are not stress relieved and will tend to walk as it heats up. By putting fore end pressure you are actually bending the
barrel upward in an ark so that as the bullet starts down the bore it is trying to straighten out the gentle bow induced by fore end pressure and it holds
the barrel against that force. This causes the bullet to exit at the same vibration point shot to shot even though there may be a velocity spread. It is best
to bed the rifle with free floated barrel as it is easy to bed the barrel with fore end pressure should it not shoot free floated. Just hold the stock in a
vice and hang a 5 lb weight to the front swivel and put bedding material in place in the fore end tip and let set up. This means that free floating is not a
panacea and does not always help. Some do and some don't This is why all factory barrels are generally bedded with fore end pressure

Found the post I was talking about earlier...and I for one would trust Mr. McMillan when it comes to a precision rifle...but that's just me.

 

[30Cal]

That won't quite work unless you pull the gas system off--the stock ferrule latches into the barrel band, so the weight will be supported by the barrel and not the stock.

I put a coathanger between the barrel and stock up near the gas cyl when I bed mine.

 

[Maverick223]

That won't quite work unless you pull the gas system off

Didn't think about that...would work for just about anything else, just not a M1, M1A/M14, et cetera. Good point.

 

[lipadj46]

Yes so you have to swing the other way and purposefully tension the barrel. People do it with shooting slings too, pull the sling tight while shooting.

 

[Retro]

Glad to see that you actually have a ARMS #18 mount installed. My receiver was out-of-spec from mil spec receiver, and it was impossible to properly install ARMS mount. I had to use the SA aluminum mount. I found that the best round for my M1As was 175 grain sierra match king BTHP, sub-MOA to 1 MOA, everything else gets me 1.5 MOA - 2 MOA.

 

[FlyinBryan]

wait?????

so m80 ball is smaller than m2 ball? or any other 308 cal bullet??

so if i buy pulled and demilled m80 ball and run them through a sizer im going to still be out of round???

 

[lipadj46]

I think someone may have been handed a load of BS.

 

[GarandOwner]

So we removed the bullets from some of the M80 ammo and installed some Sierra 168gr match boat tail bullets

Please tell me that you adjusted the gunpowder for the heavier bullet One of the first "rules" that I learned when I got into reloading is that: It is ok to use a lighter bullet on a charge for a heavier grain bullet (which will result in lower pressure and faster velocities) but one should NEVER substitute a heavier bullet on a lighter bullet charge which will result in an increase in pressure which could be potentially dangerous!

I am not trying to offend or be condescending, just saying be careful, you dont want to hurt yourself ......or your new gun!

 

[Bwana John]

So we removed the bullets from some of the M80 ammo and installed some Sierra 168gr match boat tail bullets

"Mexican Match Ammo" (and hot Mexican Match )

 

[amprecon]

The gentleman I've been working with, and learning from, has extensive hand loading and bench resting experience (40yrs?). Since I am relatively new to both I only question to learn and don't doubt his recommendations as I have nothing else to compare his suggestions too. But he didn't believe the powder charge of the M80 ball was enough to be dangerous when firing 168gr. bullets. The 168gr. bullets were seated to the maximum oal and not crimped as they weren't cannelured bullets, this may have been done to alleviate possible higher pressures, I'm not for sure.
He may be aware of the fore-end pressure bedding technique, I will find out this weekend when I take the rifle over there to get a bedding lesson on my M1A, but I will bring it up.

 

[longdayjake]

8" to 10" groups are not good or even close to what m80 will shoot out of an m1a. Though mine isn't a standard, my loaded will shoot m80 ball at about MOA all day long and its not bedded. Granted it shoots the 175 grain bullets much better.

 

[Sheepdog1968]

An other option rather than glass bedding a wood stock would be to purchase a synthetic stock. They tend to fit tighter and aren't prone to changes in dimensions as is wood. It will obviously cost more than the bedding. Just wanted to point it out.

 

[lipadj46]

8" to 10" groups are not good or even close to what m80 will shoot out of an m1a. Though mine isn't a standard, my loaded will shoot m80 ball at about MOA all day long and its not bedded. Granted it shoots the 175 grain bullets much better.

True USGI M14s had to shoot M80 ball within 5.6" at 100 yards:

From Emerson's book:

Each rifle was required to deliver its center of impact within a specified limited area around the point of aim at 100 yards with the rear sight set at eight clicks up from bottom and at zero windage. Every rifle had to group within 5.6 " at 100 yards with five rounds of M80 ball ammunition.

I doubt 8-10" groups are completely the ammo or gun's fault. Probably a combination of things.

 

[FlyinBryan]

True USGI M14s had to shoot M80 ball within 5.6" at 100 yards

yep.

most all of them in good shape will do quite a bit better. 2-3 without a fuss.
ive reloaded collet pulled demilled m80 in front of 46g of h4895 and cant really tell them from m2 ball. (1.5-2.5 from a 65 year old m1)

in fact, the only thing ive found that will out shoot them are match bullets like a-max's, nosler green ballistic tips, or nosler custom competition.

m80ball is good stuff for a service rifle.

 

[H2O MAN]

amprecon, I wouldn't go with bedding. Get a tight fitting USGI synthetic stock
and shim the gas system or save up for a M14ALCS/CV SAGE EBR stock.

 

[amprecon]

Well, the bedding job was complete, and after swapping out 160 M80 bullets with the sierra 150gr bullets, I took it to the range yesterday to check it out. After measuring the groups I realized that I may have over-estimated the large groups I had with the M80 ball initially at 8-10", they were probably closer to between 5" and 6". Mr. Ed also gave me a bunch of 168gr hornady to shoot and test for him and after re-zeroing this is the result.
Again I have an M1A standard with the ARMS #18 Mount, Millet 1" rings and Nikon UCC Monarch 6X42mm scope.
These are three 10 shot groups at 2" circles at 100 yards. The 150gr sierra's were the first group at the upper left, the 168gr hornady's were upper right and were fired second. They performed well but grouped slightly high and right. The bottom left group was again the sierra 150gr bullets, the scoped was not adjusted at all during these three 10 shot groups.
I actually got better performance from the 168gr hornady's, but it was suggested to me that for a lot of shooting, the gun was designed to use 150gr bullets and that is what I should stick with. Both 150gr groups were measured at 1 5/8" and I didn't measure the 168gr hornady's which I should have done but it appears to be better, probably under 1 1/2" several holes are actually double hits.
All in all, for what I want this rifle to do I am much more satisfied with it now and it should be able to perform satisfactorily in the field.

 

[amprecon]

BTW Mr. Ed had a "collet" he slid down over the barrel that left a space between the barrel and stock at the forend then locked it all down and left it for several days.