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i recently received a rifle from a friend who had a "gun plumber" rebarrel a win 70 in 264 wm. he has shot this round for many years and have always reloaded his own ammo. after getting the new barrel back, and firing a few rounds thru it, he cannot run the brass thru his reloading die. it just wont go all the way down. about halfway or so before it becomes so tight that he is worried it will get stuck. (yes he used lube) old fired brass from the factory barrel still runs thru the die just fine. the barrel was shown to me that it will close on a go gauge, and will not close on the no go gauge. all factory rounds will close just fine and open just fine either non fired or fired.

my question is, what would cause that.

TIA for any info.

Matt

I would expect an egg shaped or enlarged chamber. Take a round mark it with a sharpie to match a spot on the action. Then fire said round extract and rotate it 90-180 degrees and see if you can chamber it again. That’s my guess is it won’t.

Yup, either that or he over polished the chamber, leaving a small "bell" area at the chamber mouth causing the brass to enlarge when fired. If this is the case, you may need to take the rifle to a gunsmith (probably a different gunsmith) and have the barrel set back enough to rechamber it properly, rethread, and reinstall. It won't be a cheap fix....

Bob

The belted magnums can develop a bulge just ahead of the belt after multiple firings. A standard FL resizing die does not resize the area just ahead of the belt. Being the problem your seeing is after just one firing could be a improperly cut chambered as mentioned. A possible solution short of a rechamber is a resizing die designed specifically for belted magnums. Belted Mag collet die need to scroll down the page a bit. First you would neck size your brass then run them through the collet die to bring the case back into spec. I have used the die for 350 Remington mag. Works great. Did not have chambering issues. Just doing any little step to extend brass life. As soon as the brass shows slightest sign of bulging I run them through the collet die. The die is also used as a gauge to detect the bulge.Otherwise I neck size only.

My guess as well...

An oversized or eccentric chamber is more than likely what is causing the problem. Have your 'smith make a chamber cast and measure to confirm this before going to the expense of setting back and re-chambering.

How do you machine an egg-eccentric chamber?

If the barrel runs out significantly at the pilot location and the rear of the reamer is held on the center, you can machine an eccentric chamber. If a post-64 barrel is cut with threads a bit undersized and is torqued in really tight, the chamber will distort. The bigger the chamber, the worse it is. WSM's are the worst. GD

You explained it much better than I was about to... Kudos..

Have any of you professionals noticed any barrel brands more/less likely to produce a straight hole down the middle of the blank?