This is the third barrel I've chambered on my own, first was a 308 and second was a 6creed. This one is a 6creed as well done with the same SAMMI spec reamer as the previous one. Put my first rounds down it today and every one of the cases got stuck in the chamber. They were all a moderate load, 40.0 grns of H4350 and I had no pressure signs and the bolt lift was as light as my usual load of 41.5 in the previous barrel. Had to bop them all out with a cleaning rod, didn't take too much effort. I'm using the same brass/bullets/powder/primers as with the previous barrel and never had issues. Double checked headspace with go/nogo gauges and all is well, unscrewed the barrel and everything looks normal. The cases that got stuck don't have any distinct markings on them. The other barrels I've done have shot great and I never had any problems, only thing I can think of is I kinda rushed the polishing job at the end as it was getting late. My google research on polishing lead to people saying to never polish and some always polish so not sure if that's my issue. Any input is much appreciated, kinda at a dead end here
Gunsmithing cases stick in new barrel
- Thread starter idevine
- Start date
Is the chamber like a mirror finish? If so, that will commonly cause sticky primary extraction. You need a crosshatch in the chamber (green Scotch-Brite works well) to provide some gripping surface for the expanded brass and to not create that perfect "suction" against the chamber wall.
Not quite a mirror finish but pretty shiny, definitely no crosshatch going on in there. Looks like it's going back on the lathe when I get back to work on Monday. Also, I tried to chamber the cases that had got stuck with the extractor and ejector removed and bolt didn't even want to close on them. Is this because since the case stuck to the chamber wall it didn't contract, so it's like trying to put the same size gauge pin in the same size hole?
I found that using a small base die solved my issue. Brass shot in a previous barrel would stick in the new barrel.
How do the spent primers look? You could have gotten a good bit of bolt-thrust with that brass possibly. Is this new brass or fired previously?
Brass probably didn’t contract after firing since it was stuck to the chamber - to it‘s exact dimensions.
All speculation above of course, but if it was me I’d put a little crosshatching in there and re-test!
Brass probably didn’t contract after firing since it was stuck to the chamber - to it‘s exact dimensions.
All speculation above of course, but if it was me I’d put a little crosshatching in there and re-test!
The term is cold welding. When two surfaces of extremely clean and flat surfaces are put to high pressure, they weld together. So if your brass is clean and shiny, and the chamber is the same, then that explains your sticky cases.
My 338 barrel originally suffered from this, bolt lift was fine. Took it back to the smith and he put it back in the lathe and roughed up the camber a little bit with scotchbrite. Never had a problem after that.
So I repolished the chamber, started with some 400 grit with WD40 and finished it off with some grey scotch brite and got a nice crosshatch pattern. Just got to fire some rounds and was able to extract the first round but it was stiff. The next two got stuck and I had to remove with a cleaning rod. Again, no pressure signs. So could I be looking at a brass issue as JMGlasgow suggested? I noticed that a piece of fired/unsized brass from the previous barrel will drop into the chamber of the old barrel but sticks about halfway in the new barrel. Not sure if this has any relevance though. Thanks for the replies
Try factory ammo. Sounds like you're not sizing the brass far enough to get it to fit the new chamber. Either the new barrel is short on headspace, or the old one was excessive. Could just be some tolerance stacking.
Hmm, what's the likelihood that this is a Rem 700 action with zero primary cam?
Cover a piece of fired brass in Sharpie and chamber and extract it a few times. Chances are it will rub off right above the extractor groove. When brass is fired in a larger chamber like your old one, the web expands, and it's very hard to resize it. It might chamber fine in a new barrel, but once it's fired, the web has a "memory" and tries to expand back to the original size and gets stuck. This is a very common problem when swapping brass between barrels. A pass through a small base die may fix it, depending on the severity.
Got some new brass and that solved the issue, extraction is smoother than butter off a hot biscuit. Probably not worth buying a small base die to salvage my old brass, it’s getting towards the end of its life anyway. Thanks for the help everyone, as this was only my third barrel job on my own I was worried I royally screwed things up
You solved your issue, but I’m curious what the fired case measurements are. Specifically immediately above the extractor groove, and just above that where the case wall actually meets the chamber(the bulge). My chambers are pretty smooth, and I’ve never had a sticking case issue. I use 320 then 600, with no crosshatch.
The cases from the old barrel do have a slight bulge where it meets the chamber. Old brass immediately above the extractor groove is .469-.470 in both fired and full length sized cases. The bulge measures about .474 in a fired case and .472 in a sized case. Virgin Hornady brass above the extractor groove is .467, a case I fired today in the new barrel measures .468 and has a slight bulge of .4705
