Decided too try some factory hornaday 250g gmx and they shot a pattern. Vertically they were identical but they strung horizontally about 6 inches. I checked the gun everything seemed fine shot some 270g and 3/4 group. Anyone have any guesses.

Horizontal stringing is caused by:

1. pressure on one side or the other of the tang in 95% of the cases, that causes pressure in the forend and creates a false indicator.

2, Loose screws or improperly tightened of said bottom metal screws can be an ocassional problem.

3. Lastly by pressure on one side of the barrel channel from bad inletting or wood movement..but always check the tang first.

Common practice, sorry to say, is most folks go to removing wood from one side or the other in the barrel channel until an ugly gap shows up and the gun may still string shots in some cases, so its the last thing to check else you end up with an ugly forend that appears to be inletted with an axe or whatever...

I see a lot of sporters with huge gaps on each side of a barrel from free floating, and those gaps are not necessary and just gather moisture and twigs, 2x4s and rocks in some cases.

quote:

Originally posted by Johnny reb:
Decided too try some factory hornaday 250g gmx and they shot a pattern. Vertically they were identical but they strung horizontally about 6 inches. I checked the gun everything seemed fine shot some 270g and 3/4 group. Anyone have any guesses.

My guess is that your rifle does not like that load or bullet weight. If your rifle shoots 270 grain bullets or a specific load into .75" groups and the 250's into a pattern then it obviously likes one load better than another. Don't do a thing to your rifle and be happy with the 270 grain load that shoots great groups.
I'll repeat don't do anything to your rifle if you get small groups with any load, be happy with what you have....