View Single Post
Old December 3, 2012, 02:36 PM   #28
Bart B.
Senior Member
Join Date: February 15, 2009
Posts: 6,318
Big Al, the Obermeyer barrel not shanked, chambered nor crowned when tabled for the roll test. It was later chambered for the .30-.338 round and easily shot about 1/2 MOA at 1000 for 20 shot test groups with each shot fired about 25 seconds apart. So it got pretty hot from cold to whatever its temperature was.

The Winchester factory barrel was not in an action. It looked and tested pretty straight with only a few thousandths runout in its middle with each end in a V block. Looked straight, too, but the three tapers on it made it hard to check.

Regarding lighter barrels that are bent. All the M1 and M14 match conditioned rifles used for service rifle matches have the barrel bent down a bit by the stock ferrule's fit to the barrel's lower band. Their receivers are bedded such that the barrel in it rests about 3/16th to 1/4th inch more up from the stock ferrule than where it is when the hardware's put on the barrel and it's assembled into the stock ferrule when put together. This pulls the barrel down at that point at about 20 to 40 pounds of force depending on the rifle type. Barrels so set up do bend down relative to their chamber axis. But its only a few thousandths of an inch at that point becaus the stock fore end gets bent up at the same time. They all drove tacks when tested for accuracy, so their bent barrels heating up in a 20 to 30 shot string didn't suffer any point of impact change.

Gosh, that happened decades ago. 'Tis hard remembering the details of such tests back then.

Last edited by Bart B.; December 3, 2012 at 02:44 PM.
Bart B. is offline  
Page generated in 0.03936 seconds with 7 queries