Correct me ifI'm wrong-Reassure me if I'm right.

[Punch The Clown]

http://forums.thecmp.org/showthread.php?t=78769

OK, here is a thread from the CMP forum. As is always the case anything I post there is pretty much ignored because I'm not one of the "in crowd". Anyway, the OP posted that he installed a brand new Criterion barrel and it headspaced right out of the box. Since it passed go and no-go it must be good to go so all he needs is the proper grease BLO and an Orion 7 spring and there will be peace on earth. Well, I'm no expert, but I have re-barreled several Garands and unless the barrels were used they all needed the throats cut. That included my WRA SG that the CMP installed one of the NOS barrels on. Passed go and no-go but you really had to let the bolt fly to force the bullet into the throat, not to mention needing a hammer to remove the bullet. A quick pull-through reaming fixed the problem. Am I overlooking something? I've been wrong before.

[Orlando]

I am no expert on any of this but how can a commercial barrel that is purposly made so it has to be finish reamed headspace without reaming?
Heavily worn bolt and receiver??

[Punch The Clown]

Some short-chambered barrels are very close to headspacing. If you have a little receiver and bolt wear you're almost there.

[Dave]

It's possible it could be ok. If it were mine though I certainly would not be shooting it until a little further investigation. First off, with the bolt to be used stripped, I'd check to see that various brands loaded factory/surplus rounds fully chamber ok, and include your reloads if that's what you use. If all is well, next I'd mark the entire bullet ogave on several rounds with marking blue/prussian blue and chamber again, carefully remove and check with a mag glass for any signs of rifling touching the bullet. If none are present then I'd shoot it, one round at a time and carefully inspect the ejected brass for any signs of chamber issues. If ok, move to a 2 rd clip, then 5, then some 8's etc, checking all ejected brass. I do this on any rebarrel job, but especially new ones that I've reamed the chamber on. Just did this on my gas trap project. I use a Manson finish reamer and I never had any issues. It's still nice and sharp without defects but on this repro gas trap barrel I had a concern because after reaming and a thorough cleaning, I tried chambering loaded HXP which is what I shoot the most and although it chambered fine I could feel a slight resistance at the very end of bolt closure. Still closed all the way but a slight resistance noted. Did the marking blue test and had no signs of bullet touching rifling so I left it that way. It turned out to be fine, all spent brass is perfect (except heavy dings from a way to stiff ejector spring). The rifle is amazingly accurate, something I did'nt think I'd see from a gas trap setup. All I need to do now is snip off a coil at a time on the ejector spring to try and get the ejection better. It will toss brass farther than any garand I've ever shot, and it starts at 1 o'clock and each round moves further right with the last one at 5-6 o'clock. I shot about maybe 120 rds and only had two FTF. I have a repro set of duel oprod springs in it and was told I may have to snip off a coil or two on those to get it dialed in. I think for now though I'll leave those alone and see if it continues after more "breaking in". Sorry to go a bit OT from the OP. I'm just over delighted with the way this project turned out after all these years.:D

[The Garand Guy]

All the bolts are different lengths, from +1, 0, -1,-2,-3 & sometimes -4 or -5 on the bolt gauge, which I have. I have used these short bolts in a new barrel, & they headspaced without reaming. I did actually ream them out to make sure the fit was ok. Tony Giacobbe

[Punch The Clown]

OK, here is a blueprint of a .308 chamber. Notice the throat and the freebore. Also notice that the spec is given for the freebore diameter which is .310. Also note the throat tapers from .310 to .308 at a specified angle over a specific distance. All of these cuts are made by either a finish reamer of a custom throating reamer. Basically the freebore and the throat gradually compresses the bullet to its final dimension evening out the pressure rise in the chamber and lowering it. By installing a barrel in the manner that the poster on the CMP did all of these cuts would be missing-unless it was a used barrel of course.

http://i369.photobucket.com/albums/oo140/Stumedic/308_Winchester_C.jpg

http://i369.photobucket.com/albums/oo140/Stumedic/th_308_Winchester_C.jpg (http://s369.photobucket.com/albums/oo140/Stumedic/?action=view&current=308_Winchester_C.jpg)