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What's Your Experience in Accurizing an M1A?

nortac; My Springfield Armory M1A is a low-4000 serial numbered gun which may have been made before they moved from Devine, Texas to Geneseo, Illinois. It's a compilation of G.I. parts with the Springfield Armory M1A cast steel receiver. It has a SAK 1-69 barrel. Some have said these SAK barrels are "match" barrels but it offers no special heavier dimensions and I think it's only a military contract replacement barrel.

https://en.wikipedia.org/wiki/Springfield_Armory,_Inc.

The brass is very well-treated by this rifle. It don't overwork it or chew it up at all. I've made up good useful, reliably functioning loads using powders from the Reloader 7 to H 414 burning rate range. Most efforts over the years have centered around the IMR series: 3031 through 4320 with bullet weights from 125 grain to 180 grain in weight. Don't have my reloading notes to hand but can offer some "pet" loads later if you like. Never really found that others favorite pet loads offered any more than a starting point for a different rifle.

No small base dies have been necessary. In fact, setting the standard .308 sizing die to perform a complete neck re-size and a partial re-size otherwise suffices for cases run through the rifle repeatedly, such as in match shooting. I've never run the handloads on the ragged edge of maximum though.

I have seen "how low I could go" though. On one occasion I was trying to come up with an accurate, low-recoiling load for training kids so loaded the Sierra 125 grain spitzer over the minimum published charge weight of SR4759. This was a powder puff indeed. The rifle functioned with this load too, sounding all the while like my Winchester Model 12 shotgun sounds when shucking it while trying to knock down a pair of mallard from the duck blind. It's almost comical to experience. The rifle never failed to feed any from this batch of excessively light handloads. It was spic and span clean and lubricated with Singer sewing machine oil.

While not recommending such a load in an M1A, this goes to show that the rifle can function to some extent with out-of-spec rounds.

On the other hand, years ago, I went to the Texas State High Power match at Camp Bullis in San Antonio and was paired with a person who shot an M1A with some pretty gross overloads using 180 grain Sierra Matchking bullets. The rifle was holding up as far as I could tell.

There's a bit of a story on that. Was the first time I attended a state match and on Saturday morning they stuck me with a girl! She was a young woman, petite and very unassuming in appearance. I thought: "Great. First time here and I have to babysit some girl all day, spotting for her and lending a hand."

At the end of the two-day match, yours truly was 91th out of 182 match entries, or flat dab in the middle of the pack. She, on the other hand was 4th, and high woman for the match. Turns out that her dad was base commander at Lackland or Kelly (can't recall which), she shot high-power three weekends out of four all season and had a base armorer providing support for her rifle.

She was there for the two days, shooting off 180 rounds of gut-bustin' hot .308 handloads, and whipping me like a redheaded step-child.
 

nortac

"Can't Raise an Eyebrow"
Was she wearing a T-shirt that says: "Shoot like a girl, if you can!" ? LOL
I've been similarly shown up by a teenage female highpower shooter as well.
 
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nortac

"Can't Raise an Eyebrow"
Got my M1A Scout in and a Burris scout scope. Still need to order scope mounts. May be a while before I can put rounds down range. Nearest 100 yd range is in a wildlife mgt area, need to get my hunting license to be able to use it, even if I don't hunt this year. I have some stuff coming in and more on back order. Will keep ya'll posted.
 
I tried for a really long time to get my M1A under 1" and finally just gave up, I bedded the action, free floated the front end, shimmed the gas system, put Sadlak Indust. parts in it and managed to get it down to about 2" with handloads using a Burris 3X9 scope then after I shot the barrel out i had SA convert it to a Scout Squad and put a 1X4 Leu on it and it runs about 2" + on groups and i am ok with that.
 

nortac

"Can't Raise an Eyebrow"
I'm sure I'm in for a "trial by fire", pun intended. I will initially shoot it as is with some Federal 150 gr FMJs just to get the irons sighted in and see what the baseline accuracy is. I will do this before up-grading any parts. Then the real fun begins
 

nortac

"Can't Raise an Eyebrow"
Three Brothers
 

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I've had a few Burris scopes, no complaints with any of them. Not sure how I'm gonna mount it, probably use a LaRue one piece QD base and rings combo. I can see it being switched from one firearm to another as needed. I really like the Scout scope concept and would like another Marlin lever action so set up. Perhaps a bolt action scout rifle as well.

Just don't forget if you switch it from one firearm to another you will most probably need to re zero it each time!!
 

nortac

"Can't Raise an Eyebrow"
Well I finally got to the range with the M1A Scout. I fired a few Federal American Eagle 150 gr. FMJs at 50 yds. to get the Burris Scout Scope dialed in for windage. The first 5 rounds created a vertical string with the first shot from the cold barrel striking about 2 in. higher than the rest. Subsequent shots did not exhibit the vertical stringing. After about 15 rounds of the AE FMJs to roughly adjust the windage for the new scope, I began to fire lap the barrel with David Tubbs Final Finish System, consisting of Sierra 175 gr. bullets impregnated with mild abrasive polishing compounds of 10 rounds each of 5 grades of incremental coarseness, from coarse to fine. These were handloaded with a starting load of 3031. They are also available as loaded ammo. The process is to fire all ten rounds of a given coarseness, then clean the barrel and proceed with the next grade, cleaning the barrel between each sequence, for a total of fifty rounds. Very time consuming. I then switched to the 100 yd target, fired a few more AE 150 grains to adjust the elevation of the Burris Scout scope. I then fire some Federal Gold Match 168 gr. factory ammo. The gun acted like it wanted to shoot well under 2 in. but would always throw a flier or two, with three or four grouped under an inch and a half , the fliers opening things up to about three inches. I did not have time or ammo to shoot the gun at 100 yds before the fire lapping process to see what accuracy the virgin bore would produce, so I can't say for sure how much the lapping process helped, but over all I think the gun shows some promise for further fine tuning. I measured the trigger pull with the Lyman trigger pull gauge and the two stage military trigger usually broke between 5 lb. 10 oz. to 5 lb. 14 oz. Not the best for accurate target work. All firing from the bench on front and rear bags, scope on 7 X.
 
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nortac

"Can't Raise an Eyebrow"
Just thinking, will any of that abrasive get into the gas system and cause piston cylinder wear?

I have one of these on m1

http://www.brownells.com/rifle-part...tem-kits/adjustable-gas-system-prod20456.aspx

It allows me to adjust the gas to the piston, and actually use a slower burning powder safely. You can adjust it so low that the rifle is a single shot if desired.

I would think that the amount of abrasive would be minimal that would enter the gas system after handling those bullets, but I could be wrong. Perhaps do some beneficial polishing? Probably not, but probably not harmful either. Who knows. I do have one of those adjustable gas nuts on my wish list.
 

nortac

"Can't Raise an Eyebrow"
Just ordered some of the take down tools to perform the essential maintenance on the M1A as well as some more magazines.
 

nortac

"Can't Raise an Eyebrow"
After my first shooting session, I field stripped my M1A and noticed an area of contact with the stock and the bottom of the Op rod guide. I relieved that area inside the stock with a dremel tool and sanding drum. I also noted a bright spot where the gas cylinder was contacting the front stock ferrule. That I also relieved with the dremel. I have been watching and learning a lot from the tonyben3 YouTube videos. I also noticed after my last shooting session that the trigger pull was now down around #5, where it was between #5 10 oz and #5 14 oz. I took the M1A Scout out for another shooting session and got somewhat improved groups, looking less like a shot gun pattern. The best group of the day was with Federal Gold Medal Match 168 gr.
 

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nortac

"Can't Raise an Eyebrow"
In the above target, 7 of the ten rounds fall just inside 1 1/2 inches. The flier to the left is probably shooter error. I believe the two top shots were due to some continued issue with the stock. When I got the gun home, I field stripped it again and sure enough, there was still a small amount of contact area where the bottom of the Op rod guide was coming in contact with the stock, but much less than before. There was no evidence of gas cylinder contact with the ferrule. There are still a lot of things to be done to this gun and I'm feeling good that it's accuracy can be significantly improved upon.
 
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nortac

"Can't Raise an Eyebrow"
So I have relieved the inside of the stock a bit more where the Op rod guide was striking it and probably resulting in the high fliers seen on my last shooting session. I also hogged out the front ferrule a bit more, even though I saw no signs of contact, just because I had not gone to the extent recommended for a NM style modification. In playing with my trigger, I noticed that my rear hammer hooks were uneven, only one of them coming in contact with the 2nd stage sear. Apparently this is not an uncommon occurrence, but will lead to uneven and accelerated wear. So as per instructions in "The Complete Assembly Guide, Vol. 2 " by Walt Kuleck and Clint McKee, I carefully stoned the rear hammer hooks, checking the trigger pull frequently as I went. I stopped when my trigger pull measured an average of about #4 6 oz., even though the rear hooks were still uneven, but less so. I was afraid to go too far, and I may yet have to do some corrective action to increase sear engagement, but I'll see how it shoots next time out before I do anything else to the gun. I have essentially removed almost all of the creep. I had purchased the David Tubb SpeedLock spring set, but so far have only installed the Op rod spring. Have not been adventurous enough to disassemble the trigger group yet. The above stoning is done with the trigger group intact.
 

OkieStubble

Dirty Donuts are so Good.
In the above target, 7 of the ten rounds fall just inside 1 1/2 inches. The flier to the left is probably shooter error. I believe the two top shots were due to some continued issue with the stock. When I got the gun home, I field stripped it again and sure enough, there was still a small amount of contact area where the bottom of the Op rod guide was coming in contact with the stock, but much less than before. There was no evidence of gas cylinder contact with the ferrule. There are still a lot of things to be done to this gun and I'm feeling good that it's accuracy can be significantly improved upon.

Question: Could barrel heat also be a considering accuracy factor? What is the barrel length? How fast was your string of shots?

I'm curious because it appears your first 6 money shots weren't affected by any bumping or contact?
 

nortac

"Can't Raise an Eyebrow"
The M1A Scout Squad has an 18 in. barrel. It certainly was not slow fire. Shots were made about as soon as I could take a couple of deep breaths, relax and give a slow deliberate trigger squeeze between each shot. I don't think heat caused the mostly vertical fliers. Additionally, I can't say where in the shot string the vertical fliers occurred, perhaps they were not the last few rounds fired?
 
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OkieStubble

Dirty Donuts are so Good.
The M1A Scout Squad has an 18 in. barrel. It certainly was not slow fire. Shots were made about as soon as I could take a couple of deep breaths, relax and give a slow deliberate trigger squeeze between each shot. I don't think heat caused the mostly vertical fliers. Additionally, I can't say where in the shot string the vertical fliers occurred, perhaps they were not the last few rounds fired?

Is the barrel of your M1A stainless steel or the regular production parkerized barrel? The reason I ask is, because when the barrel heats up after a string of 6 or more shots, under heat expansion, the portion of the stock you cleared by dremeling when cool, could be touching again?

My experiences are few and limited in this subject matter, but I read quite a bit about this gun stuff we share, as I'm sure all of us do, and there are quite a few debates on barrel accuracy and heat, especially differing between custom vs production barrels.

Most of the stories I read, tell me that when heat is effecting the group, the later rounds from the heated barrel will walk vertically away from the group shot from the cold barrel, just as your pics showed.

In example, here is a quote from an M1A forum:

Just out of curiosity, are you vertically stringing your rounds as the rifle heats up, or is it random?

FWIW, I was having the same issue this past weekend at the range. The first round would be 2 inches higher than my point of aim, with the next 9 being within a 1.25 inch vertical string with only 1/4 inch variation on windage.


http://m14forum.com/m14/84994-barrel-heat-vs-accuracy.html

I'm probably wrong, but it might be worth some time looking into?

Hope this helps. :)
 
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nortac

"Can't Raise an Eyebrow"
Thanks Rob. I just recently joined the M14 forum and had not yet read that post. There are certainly multiple variables at work, to include my bench shooting technique. The Scout barrel is certainly not match nor SS. Given the noticed contact point between Op rod Guide and the stock, that would certainly contribute to inconsistent grouping. The Gas system is not unitized and I do not have the proper tension between the front band and the stock ferrule. Also, the fiberglass hand guard contacts the stock, which for optimum accuracy, it should be free floating. So I have several problem spots to eliminate and will do so as time and funds permit.
 

OkieStubble

Dirty Donuts are so Good.
I was pleasantly surprised to see your Scout with wooden stocks, it looks really nice. I'm used to always seeing the SOCOM version in synthetic.
 
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