308win groups

[texasbilly]

I have been testing loads with my Winchester Model 70 XTR in 308win at 100 yards. Testing 125gr and 150gr bullets, with a variety of powders (4895, 3031, varget, and others) and load weights, I have found that very light loads print sub-minute of angle groups. As powder weights increase, so do the group sizes increase significantly. I am thinking that the barrel may be moving in the stock with the heavier loads. Am I right, or is there another consideration?

 

[Klong]

Bed it and you will know. You could try tightening the stock screws also.

 

[CharlieNC]

There is an optimum charge weight for accuracy, sounds like you passed it. Google OCW load development for an example.

 

[DShortt]

I have been testing loads with my Winchester Model 70 XTR in 308win at 100 yards. Testing 125gr and 150gr bullets, with a variety of powders (4895, 3031, varget, and others) and load weights, I have found that very light loads print sub-minute of angle groups. As powder weights increase, so do the group sizes increase significantly. I am thinking that the barrel may be moving in the stock with the heavier loads. Am I right, or is there another consideration?

What is your definition of very light? Light as in, bottom of the starting load chart, or 1 grain off max which is often recommended?
Hard to guess without more details.

 

[S3silver]

If you’re at the starting charge weights then you have room to go to get to the next OCW for accuracy.

 

[Bc'z]

Targets it's hard to decifer words where targets are easier to read