- Location
- Victoria, B.C.
Hey can anyone explain this in fairly plain English what the difference is between the heavy and medium pattern barrels?

Thanks.





Twist rates for the M14 range from 1:12" to 1:10". Any of these can give excellent accuracy with the proper ammunition. I've shot 180 grain Sierra's at 1000 yards with really good accuracy in a 1:12" twist barrel, but I prefer the 1:10" twist for most of my match guns. The M118LR cartridge with it's 175 grain Sierra bullet was designed to be shot in a 1:12" twist barrel of the M24 and M40A3. I've been using this bullet at 600 yards through a 1:10" twist. It shoots great. I'll stick with the 1:10" in my personal rifles, but I think it really doesn't matter all that much.
Here is some good info I came across from a very reputable source:
The heavy barrels are long range purpose barrels. Twist rates favor big bullets like the 168gr and the heavy profile minimalizes barrel whip. Best suited for long range off a rest.
The medium pattern was first used by the US Marine corp, navy and coast guard. Reducing weight of the barrel for duty use with the medium profile and still minimizing whip. Twist rates favor more issue standard bullet weights in the 147 gr range.
Can we see some pics of said barrels to view the difference in width if anyone has pics? Thank you,
See the very interesting quote from Gus Fisher below.
"We found a significant overall increase in accuracy when we went from standard weight NM barrel to a Medium Heavy NM barrel.
... for much longer range of 600 or more yards, the best way to go is the full heavy barrel."
See the very interesting quote from Gus Fisher below.
So I would suggest the Medium Heavy is inherently more accurate than the standard weight barrel no matter what stock you put it in.