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Discussion Starter · #1 ·
Have a standard SAI M1A with a few mods. Although I've reloaded handgun for years, I've not yet reloaded for rifle.
Having experimented with several NATO and commercial variants, my most accurate round to date has been with 147 gr, Dag. These provide the most accurate and consistent groups so far. The worst results having been 168 gr.HPBT Federal Gold medal match and 175gr. M-118. I'm a bit confused by this as I've been told the Sierra is somewhat of a gold standard. My stock, 6 groove,1:11 RH twist just likes 150gr. or less projectiles. I know every barrel is different, but all things being equal, what are some of the variables here? Twist/bullet weight?What else?
 

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wow at the worst groups being with Gold Metal Match. That has been my all-time best performer. Just started shootin it a few months back. Expensive but way accurate in my toys.

I'd check the flash suppressor for bullet hits. Never know though... some rifles are finicky like that. Could be a headspace thing too. Maybe some of the other guys can take a spin on that.

Good luck with the hunt!
 

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Discussion Starter · #3 ·
Head space measures 1.631. No marks on FH.
Mods include, M-25 unitized gas .Sadlak NM guide rod and NM piston, NM trigger,NM sights.Trigger group and action are tight in Walnut stock. Front band and ferrule releaved as well as HG . Your response that the 168gr SHBT Gold Medal is your Fav for accuracy is what I've heard several times. This is what confuses me.
 

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That is interesting. Maybe the extra bullet weight and ensuing recoil and vibration have caused more barrel movement. I would go back and check for marks on the stock or ferrel again since switching ammo. Look at the bottom of the gas cylinder too, just inside the barrel band for marks. Something is definately askew. Clean the chamber well with the chamber brush, mop out with solvent and copper wash, then clean with brush again. Check overall length on the cartridges compared to each other and bullet set-back from the rifling. Some M14's do not like bullets with no jump.
 

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My 'guess' is that somehow the gas piston is more 'tuned' to the lighter bullets.
By 'tuned' I mean small differences in how and when the moving-parts of the gas system operate with different loads.
Swaping & testing different pistons in M14s was done by military teams (who have access to many pistons) in order to find one that gave the best accuracy.

If you want to tinker, I'd start by trying the standard piston and see how that works.

The Sierra 150 MK is a good bullet and might be a good choice in your rifle.

Jay Kosta
Endwell NY USA
 

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Have a standard SAI M1A with a few mods. Although I've reloaded handgun for years, I've not yet reloaded for rifle.
Having experimented with several NATO and commercial variants, my most accurate round to date has been with 147 gr, Dag. These provide the most accurate and consistent groups so far. The worst results having been 168 gr.HPBT Federal Gold medal match and 175gr. M-118. I'm a bit confused by this as I've been told the Sierra is somewhat of a gold standard. My stock, 6 groove,1:11 RH twist just likes 150gr. or less projectiles. I know every barrel is different, but all things being equal, what are some of the variables here? Twist/bullet weight?What else?
Looks like you've discovered some advantages (shoots German milsurp well), but you'll discover disadvantages trying to hold a POA with it at 500-600 yds. If you can track down a box or two of U.S. M852 (it's the 168 SMK) and try that with a clean, well-lubed rifle, you'll probably like it.
 

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Having experimented with several NATO and commercial variants, my most accurate round to date has been with 147 gr, Dag. These provide the most accurate and consistent groups so far. The worst results having been 168 gr.HPBT Federal Gold medal match and 175gr. M-118
The 1:11 barrel has traditionally been the barrel that was designed to shoot the 168 - 175 grain bullets for long range competition. Dag ammo has mixed reviews but mostly it has a good reputation (the accuracy seems to vary depending on lot numbers).

Could you define "most accurate and consistent"? I mean, at what distance were you shooting?, what shooting position?, rapid fire or slow fire?, supported or unsupported?, optics or open sights? What kinds of groups are you expecting?
 

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Discussion Starter · #8 · (Edited)
The 1:11 barrel has traditionally been the barrel that was designed to shoot the 168 - 175 grain bullets for long range competition. Dag ammo has mixed reviews but mostly it has a good reputation (the accuracy seems to vary depending on lot numbers).

Could you define "most accurate and consistent"? I mean, at what distance were you shooting?, what shooting position?, rapid fire or slow fire?, supported or unsupported?, optics or open sights? What kinds of groups are you expecting?
Sure. Slow fire. Max distance 200 yd's from a front rest only.
Both Irons and scoped. Producing only slightly better accuracy results with scope even at 200 yards. 10 shot groups at 200 can Usually be covered with my hand which I consider acceptable for a basically stock Battle rifle. I understand some of the variables,i.e. no bedding, not match barrel. Photo depicts 200 yard target. 8" bull. 60 deg Far. light wind. 10 shot bottom right group is irons. Top 5 shot group is scoped,(Kahles 2.2x9 x 42) on Basset low picatinny mount. the 3 shots in the 9 ring are me not doing my job. To add: the rifle will consistently put a full 20 shot magazine of Dag into the head of a B-27 target at 200 yards with iron sights.
 

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Sure. Slow fire. Max distance 200 yd's from a front rest only.
Both Irons and scoped. Producing only slightly better accuracy results with scope even at 200 yards. 10 shot groups at 200 can Usually be covered with my hand which I consider acceptable for a basically stock Battle rifle. I understand some of the variables,i.e. no bedding, not match barrel.
Thanks, I asked only to try to help cuz we all speak our own language and I've found out the hard way that I'm prone to assume too much about what the person's intent was.

So, both scoped and irons at 200 yards and about a 5" group with 10 shots. I assume that was the 168gr ammo?

Any time you are troubleshooting accuracy issues you need to return to the basics and look at three areas;
  • The rifle
  • The ammo
  • The shooter

Since you said that there wasn't a lot of difference between irons and scope I would assume (that just might be the death of me yet) that the rifle isn't really the problem. If it were then you should always get the unacceptable groups regardless of ammo or anything else. The ammo is widely accepted as the gold standard to test against so we can assume that it isn't the problem so that only leaves one thing...please don't be offended I don't mean to insult anybody, I'm just trying to help troubleshoot something that most people have great success with and isn't working in this instance.

You mentioned a front rest, what part of the fore end of the rifle was on the rest? You will always get your best accuracy if you place the rest somewhere between just forward of the magazine and the just behind the front sling swivel. Anything farther back...well that's obvious, and anywhere forward of the front sling swivel and you tend to push the barrel around while you are shooting. That will induce inaccuracy and larger groups. Did you use a sling? If so then how tight was it? Some people tighten the sling to the point that it actually flexes the fore end of the stock which torques the muzzle. As you squirm and move the muzzle changes position. What kind of stock? Wood stocks, short of an aluminum frame, are by far the most reliable stock in regards to not flexing. Polymer stocks, especially the newer ones, suck...there is no other way to say it.

On the other hand, I recently looked at a new standard model in a polymer stock and I noticed several areas that could use tweaking to improve accuracy.
  • The hand guard was touching the stock and the front band to the point of being jammed tight.
  • The front band was touching the gas cylinder.
  • The op rod was dinging the receiver on the right side just about where the receiver ring is (the chamber opening).
  • There was no stock liner, just molded plastic and the receiver fit loosely.

The only things that I can think of that could interact with different bullet weights are the twist rate (1:11 should be golden for the 168s), the free bore length in the barrel (different bullet weights usually result in different bullet lengths and that results in different distances for the bullet to jump to the lands). Maybe try a 175gr load and see what happens. Heavier bullets should, theoretically, perform better at longer distances than lighter bullets, and they usually do. So if the 175gr works and the 168gr doesn't then there is something really quirky with the chamber. If the 175gr doesn't work then it seems like all heavier/longer bullets don't work well and then I would still be worried that there is something wrong in the chamber.

And finally, if you have never shot an M1A before and if you have far more experience with pistols then there will definitely be a learning curve. I used to shoot pistols a lot (like 500 rounds per week for several years through semi autos and single actions) so I know that while you can be very good with a pistol, you need just as much practice with a rifle to be good and the M1A takes just a little more practice to get used to the old wood and iron style.

Good luck, and I hope you solve this one cuz it's nice to shoot tight groups with these rifle and impress the other guys on the range. DI5
 

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Discussion Starter · #10 ·
Thanks, I asked only to try to help cuz we all speak our own language and I've found out the hard way that I'm prone to assume too much about what the person's intent was.

So, both scoped and irons at 200 yards and about a 5" group with 10 shots. I assume that was the 168gr ammo?

No. that was 147 gr Dag. 168 smbt would have been worse.

Any time you are troubleshooting accuracy issues you need to return to the basics and look at three areas;
  • The rifle
  • The ammo
  • The shooter

Since you said that there wasn't a lot of difference between irons and scope I would assume (that just might be the death of me yet) that the rifle isn't really the problem. If it were then you should always get the unacceptable groups regardless of ammo or anything else. The ammo is widely accepted as the gold standard to test against so we can assume that it isn't the problem so that only leaves one thing...please don't be offended I don't mean to insult anybody, I'm just trying to help troubleshoot something that most people have great success with and isn't working in this instance.

You mentioned a front rest, what part of the fore end of the rifle was on the rest? You will always get your best accuracy if you place the rest somewhere between just forward of the magazine and the just behind the front sling swivel. Anything farther back...well that's obvious, and anywhere forward of the front sling swivel and you tend to push the barrel around while you are shooting.

The rest was btween front swivel and Mag. inaccuracy Did you use a sling?

No sling



[*]The hand guard was touching the stock and the front band to the point of being jammed tight.

HG is releived and frnt. band and ferule are reamed.

[*]The front band was touching the gas cylinder.
No
[*]The op rod was dinging the receiver on the right side just about where the receiver ring is (the chamber opening).

Op rod is perfectly aligned and strikes the piston squarely.

[*]There was no stock liner, just molded plastic and the receiver fit loosely.

It's tight

Receiver and trigger group are tight in the stock


The only things that I can think of that could interact with different bullet weights are the twist rate (1:11 should be golden for the 168s), the free bore length in the barrel (different bullet weights usually result in different bullet lengths and that results in different distances for the bullet to jump to the lands). Maybe try a 175gr load and see what happens.

Tried 100 rounds of M-118 175 gr. Miserable results.

Heavier bullets should, theoretically, perform better at longer distances than lighter bullets, and they usually do. So if the 175gr works and the 168gr doesn't then there is something really quirky with the chamber. If the 175gr doesn't work then it seems like all heavier/longer bullets don't work well and then I would still be worried that there is something wrong in the chamber.

And finally, if you have never shot an M1A before

USMC 1968 M-14 Sharpshooter


and if you have far more experience with pistols

Admittedly, my discipline is handgun.

then there will definitely be a learning curve. I used to shoot pistols a lot (like 500 rounds per week for several years through semi autos and single actions) so I know that while you can be very good with a pistol, you need just as much practice with a rifle to be good and the M1A takes just a little more practice to get used to the old wood and iron style.

Good luck, and I hope you solve this one cuz it's nice to shoot tight groups with these rifle and impress the other guys on the range. DI5
Thanks for the reply
 

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Thanks for the reply
I'm glad I didn't try to get on my high horse and say anything about your experience with the rifle, Semper Fi, been there done that too, I retired after 20.

Anyway, I'm concerned that it isn't hitting well with anything that is heavy. I do wonder about the throat or something in the chamber area. I usually get no worse than about 2" groups with my loaded model and about 5" groups with my SOCOM at 200 yards using 168gr Fed.GMM so I know it's possible to get better groups than you are getting but danged if I have a good direction to go to solve the problem.
 

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Discussion Starter · #12 ·
I'm glad I didn't try to get on my high horse and say anything about your experience with the rifle, Semper Fi, been there done that too, I retired after 20.

Anyway, I'm concerned that it isn't hitting well with anything that is heavy. I do wonder about the throat or something in the chamber area. I usually get no worse than about 2" groups with my loaded model and about 5" groups with my SOCOM at 200 yards using 168gr Fed.GMM so I know it's possible to get better groups than you are getting but danged if I have a good direction to go to solve the problem.
Well, Hell. Maybe it's just my 61 year old eyes! But your right. Won't shoot heavies.
I actually thought I was doin OK with the Dag but with folks getting better groups with the 168gr. I just don't know. Am reluctant to do anything else to the rifle other than maybe saving up for a Kreiger Med/heavy barrel and bedding.
I'm regularly shooting my Les Baer 1911 into basically one large hole at 50 feet off-hand so I really don't think it's my eyes, but they sure ain't what they used to be. My CZ bolt .22 puts them in a dime at 50 yards. I acquired the M1A new as a trade for 3 pistols last year out of nostalgic feeling's for my old M-14. Maybe it's time for one of those fancy bolt guns! MCORPS1 Semper Fi
Thanks for your time and help sir.
 

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My Kreiger 1:10" shoots heavier bullets very well. it's the twist that was recommended when I built it.
Check the seating depth, that may be the difference in the barrels as well.
Cheers
 

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Sounds to me like you can put in the bull fine jens5, maybe it is just the twist but I'm running a 1:11 barrel in my loaded and I get very good groups with my 168gr bullets. At least it's nice to know that I'm not the only M-14 lovin', .45 carryin', jarhead around. DI5
 

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That is interesting. Maybe the extra bullet weight and ensuing recoil and vibration have caused more barrel movement. I would go back and check for marks on the stock or ferrel again since switching ammo. Look at the bottom of the gas cylinder too, just inside the barrel band for marks. Something is definately askew. Clean the chamber well with the chamber brush, mop out with solvent and copper wash, then clean with brush again. Check overall length on the cartridges compared to each other and bullet set-back from the rifling. Some M14's do not like bullets with no jump.
I missed rip's post, I guess I should pay more attention...
 

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Discussion Starter · #17 ·
That is interesting. Maybe the extra bullet weight and ensuing recoil and vibration have caused more barrel movement. I would go back and check for marks on the stock or ferrel again since switching ammo. Look at the bottom of the gas cylinder too, just inside the barrel band for marks. Something is definately askew. Clean the chamber well with the chamber brush, mop out with solvent and copper wash, then clean with brush again. Check overall length on the cartridges compared to each other and bullet set-back from the rifling. Some M14's do not like bullets with no jump.
We"ll do Rip. Thanks or the advice
 

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Those are good 10 shot groups for a standard at 200yds. Sounds like you found what your rifle likes. I'd buy a lot of 147 gr, Dag and be happy. Don't change a thing. Though I'm curious if you've tried AE 150grn FMJBT in a side by side comparison?
 

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I'm a little lost. The groups (5 shot and a 10 shot group) on the target--were those 168's?

If you centered those groups on an SR-2 highpower target (the standard 200yd), you'd have a clean score.

IME, the 168 SMK is very insensitive to jump distance. It doesn't not have a reputation for being picky.

I'd need to see quite a lot of groups to be convinced that a military FMJ outshoots the Matchking. As Zediker put it, "if it won't shoot FGMM, it's cursed."


I'd go for just the bedding job and see what you get. It'll probably do pretty good without adding the extra pound that the medium wt barrel adds. I've seen enough targets shot with USGI barrels to know that they'll shoot nicely more often than not if the stock is tight/bedded.
 

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Discussion Starter · #20 ·
Those are good 10 shot groups for a standard at 200yds. Sounds like you found what your rifle likes. I'd buy a lot of 147 gr, Dag and be happy. Don't change a thing. Though I'm curious if you've tried AE 150grn FMJBT in a side by side comparison?
I haven't, but I'll give it a try. Thanks
 
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