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c_tappy
03-02-2015, 06:51 PM
Hello
I just changed the barrel on my savage 308. The bolt will close on the go gauge and wont close on the no go gauge (click, then not even a quarter turn), went to the range and the bolt wont close on a live round (MFS 149gr fmj factory round, or Federal power-shok 180gr soft point).
Is the headspace to tight, should the bolt close more on the no go gauge?
Any help would be greatly appreciated!

KRP
03-02-2015, 10:09 PM
What part of the loaded ammo is actually stopping the bolt from closing?

Dennis
03-04-2015, 03:45 AM
The bolt will close on the go gauge and wont close on the no go gauge (click, then not even a quarter turn),

Define quarter turn.

I usually adjust my no-go so that the handle is about 1/2 of the allowed travel.

Once I adjusted one "with a no-go gauge" and the handled stopped after about 1" of travel.

I also experienced the same trouble you are experiencing. I reset the head space, probably opened it up .001 to .002 more and all was OK. The no-go gauge still stopped the bolt travel, maybe 2/3 allowable travel used. I have never had a problem ever with this rifle.

I believe the difference between both gauges is .005 to .008 . Another words, your go gauge is 0 , your no-go gage may allow up to .008 more travel, but something is telling me it may be .005 . Somebody will kick in and verify this statement

sharpshooter
03-05-2015, 01:21 AM
Most people don't understand what is called a "geometric tolerance". The difference between minimum and maximum SAAMI headspace is .010". The difference between a go-gauge and a no-go gauge is .005", with a tolerance of +-.001. (The no-go could be as little as .004", and as much as .006" longer than the go-gauge.) The difference between the gauges has to fall within that window of the .010" in the chamber. This being said, not everyones gauges are exactly the same, but they are still within tolerance.
Then you have a different set of dimensions for ammunition. It is possible to have a chamber that is within SAAMI specs on the bottom end, and also have ammo still within specs on the top end, and it will not chamber.
SAAMI specs are not carved in stone like everyone thinks, they are merely an industry guideline. Most manufacturers hold the tolerance closer on critical aspects like bore size and headspace dimensions, and use their own version of throat dimensions. This is called "voluntary industry specs."

Dennis
03-05-2015, 03:18 AM
Thanks Sharpshooter, that sums it up.

After he resets his headspace, he should be all right.

Robinhood
03-05-2015, 12:30 PM
Great explanation. It is always good to see a post when author has a command of the jargon, professional experience and their summary is well written. No insults. Just the facts.

c_tappy
03-08-2015, 09:47 PM
Perfect guys, took it out to the range, everything is great!
thanks very much!