My fitter-turner buddy has a heavy, .308 Omark barrel he would like to turn down to a sporter contour but worries that its having been hammer-forged might add complications.

The spiral pattern on the outside of this and other HF barrels makes us wonder whether the contour should be be part of the rifling process.

That spiral pattern is just there for cosmetic purposes; it has nothing to do with the rifling. The real question is, was it properly stress relieved. If so, you can turn it down. If not, you will create a blunderbuss.

I have found hammer forged barrels to be relatively stress-free and have had no issues when turning them down. I have re-profiled a bunch of Remington barrels, as well as hammered barrels from Steyr, H-K, Swiss Arms, and Winchester, and never saw any warpage or dimensional change with any of them. Interestingly enough, the very worst barrels I ever turned were cut rifled. Regards, Bill.

I agree; and the crooked ones I have had, were all cut rifled too, from a maker who shall not be named.
Which is why I only use one maker; I won't mention their name either, since some guys went crazy when I did. Actually got 4 barrels in from them today. One 50 cal, an 8mm, a 257 and a 35. You know who they are....

Doesn't hammering remove the stress from metal?

I'm thinking of how they shot peen piston connecting rods in engine building to reduce any stress cast into the metal.

Thanks everyone, I'll pass your thoughts on to my buddy.

Dpcd, how will he know if the barrel has been stress-relieved beforehand?

They are stress-free as produced, in my experience. Remington produced a lot of barrels with ripples from one end to the other, but I have not seen this from any of the other makers. Correction; I saw some barrels with ripples from Winchester after they moved from New Haven, but they were rare. The Swiss barrels I saw were truly excellent barrels, so were the Steyrs. Regards, Bill

Interesting commemnts re unstable cut rifled barrels.

I've found the Kreiger, Dougblas and Lothar Walther all remain spot on when cutting integral patterns, I've been told that Pac Nor also holds up well.

The tail stock pressure has to be closely monitored or big trouble will result from ANY barrel

Some cut rifling makers, secure in the supposition that their method imparts no stress to the material, do not stress relieve as a part of the manufacturing process. If the material they are using is stress-free, everything is fine. If not, as was the case with the barrels I referenced, they warp to beat hell. Even material which is sold as stress relieved, is not always so. I have had similar experience with the barrels you mentioned and others. I have milled some Shilens with no issues as well. All are stress relieved as part of the process. Regards, Bill

If we don't know, should we whack the barrel with a hammer, as per that weird AR thread recently?

You'd think that with hammer forging, it might have been whacked enough and that with no mandrel to limit internal deformation some squishing there might occur

It is, of course, an overweight barrel so might stand some abuse.