M14 barrel heating moving POI downwards

F

fat but funky

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Hi Folks,

New to this area of CGN.

I have a norinco M14 that shifts POI downwards as the barrel heats. I had brought this up in the main battle rifle forum some weeks ago. Some had told me that the problem is likely some sort of interference in the area of the stock ferrule with the flat bit of metal that covers the stock ferrule when the rifle is assembled (I think they called it a barrel band, but that isn't what I think of when I think of a barrel band).

Anyway, despite looking through one of the books they mentioned, I have not been able to come up with a fix for the problem.

Does anyone here have any ideas?

Thanks

Fat
 
Grease the ferrule, then report back.

Otherwise, you could diddle around with the trigger guard tension, but try the grease first.
 
It is called the "front band" and mates to the stock ferrule. While unitizing the gas system may help (I think there is a sticky here about this) I have never heard of this type of problem nor experienced it with my Norincos.

Mind you, my rate of fire is not enough to heat up the barrel to the point where I have to worry about the POI. Not sure many Marines worried about POI in 'Nam, and there are a lot of champion shooters in the US right now that swear by the M14 platform.

If this problem continues, I suggest you have it re-barreled.
 
Turf said:
Not sure many Marines worried about POI in 'Nam, and there are a lot of champion shooters in the US right now that swear by the M14 platform.
Click to expand...

Ummm, not really. The AR mousegun "platforms" absolutely dominate US High Power shooting because the M1A/M14 hasn't been competitive for a decade. (Even though the designated marksmen are using M14s in combat, there are reasons why the multitude of military rifle teams aren't using M14s in the matches?)

To get back to the original question - how many shots do you have to fire to get this drop in point of impact? Secondly, are you shooting iron sights or scope? How much of a drop are you experiencing? I suspect this is a problem behind the butt rather than something wrong in front of the butt.
 
Usually first 5 rounds are fine - get a group maybe 1.5" which is fine for me.

A second group of 5 might show 2 inches vertical string.

After that, it just gets silly. The most I have seen is 4 inches string between first and last shot of group. At the end of that group, the barrel is quite warm. You can keep your hand closed around the barrel, but it isn't necessarily pleasant - but no burns.

I am quite convinced this is some sort of mechanical issue. When I try handloads, the hotter the load, the faster this process occurs.

Shooting with 2-7 leupold scope on leupold rings and an ARMS 18 mount.

Fat
 
My first suggestion is still a problem with the carbon interface. The rifle is likely very capable of outshooting the shooter.

I have found shooting scoped rifles to be a humbling experience. I too tend to shoot vertical groups whenever I shoot groups. The error is where I place my head relative to the rear lens. The problem is the shooter has to be very conscientious with cheek weld and head placement. Holding on the edge of my chin gets uncomfortable and the butt sits too low on my shoulder. All scoped M14s and any rifle with see-through rings move the head higher off the stock than the designers intended.

I am building an M14 stock "elevator" that will overcome this problem. More to follow.

(forgot to add - eyeglasses and high-index lenses aggrevate this alignment problem)
 
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"...can keep your hand closed around the barrel..." Which indicates we're not talking about rapid fire. This is good.
Obviously, the barrel is being pushed down as it heats up. Shot stringing is usually a bedding issue. It's not likely the scope mounting as it's ok with a cold barrel.
Is the rifle glass bedded? All the screws, including the gas plug, tight?
 
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