My chamber is tight on my new 308. Even factory Fed GMM gives me a tight bolt closure. I bumped the shoulder .002" but it's still tight but slightly better.
Question is how much bump is safe?
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My chamber is tight on my new 308. Even factory Fed GMM gives me a tight bolt closure. I bumped the shoulder .002" but it's still tight but slightly better.
Question is how much bump is safe?
You bumped the shoulder on the factory ammo? Or are you talking once you fired?
More information is needed to understand what you are talking about. Are you sure it is tight on the shoulder- and not that you are jamming the bullet?
I had a similar problem with two new .308 Savage barrels in 2011.
Both bolts wouldn't close easily on .308 Federal GMM rounds.
Turned out that the new barrel chamber depths were 0.006 short of the 2.800 SAAMI OAL spec and the GMMs were around 2.796 OAL.
I put the factory rounds in my seating die and moved them back to 2.793 OAL and the bolts closed easily.
On my rifles, it wasn't the shoulder, it was the bullets being shoved into the lands.
After 100 rounds fired, the bolts closed easily on all factory ammo.
Those two rifles now have over 4,000 rounds down their barrels, and they still shoot as well or better than new.
Problem is with BOTH factory Fed GMM 168 and new sized & trimmed Hornady brass.
I measured the CBTO with a Hornady Guage and minused .005", so no, the bullet isn't jamming.
It is possible that the reamer for the chamber was mis-adjusted and didn't go deep enough.
Savage is pretty good at quickly fixing those kinds of problems.
They took less than two weeks to rebore the chamber on my 12 LRP that was too tight and caused high pressure signs, even on loads that were at the minimums on the load table. Of course, I had to send my rifle back but they paid shipping both ways.
That problem was probably caused by a well-used reamer that had used too long.
How does the bolt close on a new, unsized, empty, Hornady case?
Tightly.Quote:
Originally Posted by PhilC
Sounds like what CFJunkie pointed out. You gots a tight chamber.:( Might want to yourself, or get to someone who can headspace it with a tad more. I’ve never heard of NEW factory brass needing the shoulder bumped.
So thoughts....
1) It is just screwed in a little to far and you can back the barrel out and set correct headspace. Easy- but the markings on the barrel will not be perfectly oriented anymore.
2) The chamber is not deep enough- you can still back the barrel out and get correct headspace- but you will have more unsupported case head than what is called for. It sounds like it is just a few thousandths that you need so probably not a issue. But without seeing the barrel it's all just a guess.
Do you have access to a go-gauge? I would try a gauge before I sent it back to savage- but if it doesn't check out and is a new rifle then may as well let them deal with it. I had a gun that I couldn't get enough bump with the re-sizing die and did the fix where you take a little material off of the shell holder to get more bump- but it was always a pain and should have just fixed it at the start.
Agree reamer was worn or headspace was set tight. Since it's new and under warranty, I'd contact Savage and have them correct it.
My apologies.. I overlooked it was new. Yes, if it’s still under warranty, don’t give a second thought. Send it to Savage and have them deal with it.
Contact Savage first, explain the problem - especially that the bolt won't close on factory ammo, since they tend not to put much credence on hand loads - and they will send you a shipping label that is pre-paid.
Otherwise, you'll be paying for shipping when you don't have to.
You might want to buy a set of go, no-go gages and check it out before sending it back. If it is indeed short chambered, they may just back the barrel out a few thousandths, or replace it anyway so the engraving is properly aligned. Once it's back, I'd check it again with the gages. I've gotten a rifle back from warranty work and found the no-go gage chambered easily. I put a layer of Scotch Tape on the head of No-go gage and retested, and the bolt closed stiffly, so it wasn't out by much but it was nevertheless out of spec. I simply cracked the nut loose, and turned it in a tad until the go gage fit snugly with one layer of tape on the head. There were some brands of ammo that would not chamber easily or at all, but I mostly shoot hand loads so it wasn't an issue.
On my Savage .308 shooting FGGM 168 gr, the bullets seated .005 INTO the lands on that rifle, so that's where I seat my hand loads and they shoot well enough to win prizes. What's not to like?
As was mentioned....Most likely the head space is off.