Success! - fixed dropping POI on m14

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fat but funky

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Hi Folks,

I have put a couple of posts on here asking what could be done about a POI that shifts downwards as the barrel heats.

There was alot of speculation about bedding the rifle. Turned out, this wasn't the case in my situation. On fellow did mention that it could be too much pressure between the barrel band and the stock ferrule.

Rather, it was a lack of contact between the stock ferrule and the band. I had read somewhere that one should have between 4 and 7 pounds pressure applied between the "tab" of the barrel band that overlies it. In my rifle, there was no contact at all. A 2-3mm gap existed between those two structures.

Not wanting to start bending metal that might crack or break, I added a dab of JB Weld onto the stock ferrule, then sanded it smooth until the 'tab' of the barrel band would just barely slide over top as I reassembled the gun.

Anyway, took it out yesterday, and the progressive downward shift is gone. No doubt, bedding the action would improve accuracy more, but I am getting 1.5" groups as it is, and that is fine for me.

I don't really understand the mechanics of the problem, but it seems to be fixed none the less.

Just putting this out there for anyone who is having a similar problem.

Fat
 
fat but funky said:
Hi Folks,

I have put a couple of posts on here asking what could be done about a POI that shifts downwards as the barrel heats.

There was alot of speculation about bedding the rifle. Turned out, this wasn't the case in my situation. On fellow did mention that it could be too much pressure between the barrel band and the stock ferrule.

Rather, it was a lack of contact between the stock ferrule and the band. I had read somewhere that one should have between 4 and 7 pounds pressure applied between the "tab" of the barrel band that overlies it. In my rifle, there was no contact at all. A 2-3mm gap existed between those two structures.

Not wanting to start bending metal that might crack or break, I added a dab of JB Weld onto the stock ferrule, then sanded it smooth until the 'tab' of the barrel band would just barely slide over top as I reassembled the gun.

Anyway, took it out yesterday, and the progressive downward shift is gone. No doubt, bedding the action would improve accuracy more, but I am getting 1.5" groups as it is, and that is fine for me.

I don't really understand the mechanics of the problem, but it seems to be fixed none the less.

Just putting this out there for anyone who is having a similar problem.

Fat
Click to expand...

Thanks for the information. But I am not absolutely sure what a "stock ferrule" is. Would it be possible to post pics?

BB
 
Where did you get the 4-7 lbs suggestion? I asked the same question on the American boards and was told 30-40 lbs. The way I acheived the pressure was though epoxy bedding of the action with a spacer placed beneath the barrel and the stock forend. When you remove the splacer and tighten down the action into the stock, the forend will have preload on it, having been bedded that way.
 
It might have been on another gun board, but honestly, I don't remember.

I can't vouch for the validity of the 4-7 pound number. All I can say is that a dab of JB weld and some sanding seemed to do the trick for me.

I have no idea how much pressure is being exerted in my rifle - sorry.

Fat
 
fat but funky said:
It might have been on another gun board, but honestly, I don't remember.

I can't vouch for the validity of the 4-7 pound number. All I can say is that a dab of JB weld and some sanding seemed to do the trick for me.

I have no idea how much pressure is being exerted in my rifle - sorry.

Fat
Click to expand...

As long as its working for you that's all that matters. I'm not really sure of the tension of mine, I'd have to come up with some sort of contraption to measure it. Its sure not 30-40 lbs, much less. 10-15 lbs maybe??? Anyhow, mine shoots great and that's all that matters. I'm very careful that if I shoot it off a rest to not place the rest out at the end of the stock. I think that affects point of impact if you are really counting on accuracy. I'd like to get some of the recommended books and read up on the subject of tension and bedding.
 
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