.416 Info needed


Well-Known Member
Aug 25, 2012
NW Minn
I've built a couple of .416 Weatherby's.
I've got a few questions for those in the know.
My .416's have 1 in 12" twist barrels. These guns weigh about 15 lbs.
When shooting 300-325 grain jacketed bullets above 2800 fps, my groups really start to open up.
I've read and heard that alot of the guys with 416 Barretts are using 1 in 14" twist barrels for loads at 3100 fps and above.
Do you think I have too much twist in the barrels at 1 in 12"?

Another problem is that when I shoot the barrel warm ( meaning 3 shots or more) the jacketed bullet groups open up from .5 MOA/.75 MOA to 1 1/2 MOA.
Cold bore groups, the gun is very accurate.
Any amount of heat in the barrel and the groups open up significantly.

Too much twist in the barrels? Are the 1 in 12" barrels better for the longer, heavier .416 bullets such as Cutting Edge?
Or is it barrel harmonics/vibrations?
Any thoughts?
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