M-14 barrel heat moves POI down

[fat but funky]

Hi Folks,

Some time ago, I asked a question regarding vertical stringing with my M-14S

Have since started handloading, and have made a new discovery regarding the issue - it is definitely heat related.

If I fire 5 shots, the first 2 will be almost touching each other. The rest always string downward. If I let the barrel cool, the next shots will be up near the first. Cleaning the barrel seems to have little to no effect.

The hotter the load, the more rapid and severe the shift in POI. As it is now, the hottest load I have tested (155 gn A-MAX over 45.5 gn IMR4895) puts the first shot almost exactly where I aim. Next shots are a good 3.5" low at 100 yards. Interesting thing - once it deflects that much, so long as the barrel stays warm, the shots start to string horizontally.

So, is there anything I can do about this?

Please note that when I say a hot barrel, I mean noticably warm to the touch. It never got to the "too hot to hold on to with bare hands" stage. I had heard that the hand guard can cause heat related shifts in POI. So, I took the handguard off and tried again. Same story. So it would seem the handguard is innocent in my case.

Fat.

 

[Savage]

This is caused by to much pressure being applied at the Stock Ferrule and Gas Cylinder IE front of stock and can occur with this style of rifle

 

[fat but funky]

Thanks for the info.

So, now, how do I fix the situation?

Do I have to grind away metal somewhere, or is there a less invasive fix?

Thanks again

Fat

 

[Wendell]

Detailed instructions are found in books found here:

http://www.scott-duff.com/

http://www.gunbooks.com/us30.html