Headspace? Bolt hard to close sometimes.

[ACES&8S]

No expert on headspace or lots of other precise adjustments on rifles but
I am mounting a scope for a fellow & I am using factory ammo in a
T/C Venture 30.06 & ran into a problem I sometimes find in cheap military
bolt actions with mismatched numbers on the bolt vs the receiver where the
bolt is Hard To Turn Down & Close.
I tried my reloads in it & they weren't any worse or better for that matter.
The fired cases look great & don't have any turn marks like the bolt caused any
scratching, the head stamp looks good, & overall normal.
What gives? What are the possible reasons for this tight fit on the T/C ?
Note: I tried 3 different types factory cases for function, about 1 of every 2
or 3 would be tight, not every case.
And while I am at it, I don't own any like this but I know of several that have these
mismatched military bolts that are hard as heck to close, isn't that dangerous?
Do they just throw any surplus bolt in one that will fit?

 

[taliv]

headspace is a possibility, especially if it's new to you. if it's worked for years and suddenly doesn't, then it's unlikely to be a headspace issue

another possibility is an obstruction in the chamber. "carbon ring" or maybe some dirt or something. try marking the rounds with a dry erase marker and chamber them and see what part gets wiped off

 

[WestKentucky]

Sounds silly, but could be dirty lugs. Clean the gun, and when you find a tight one pull it out flip it around arbitrarily and rechamber it. If it's still tight then you know your chasing a sizing issue. If it chambers normally you know your chasing a mechanical problem such as crud in the mechanism.

 

[entropy]

Both the above posts are good advice. Clean the gun good first, if it still does it, try the dry erase marker trick.
As for milsurp bolts, depends on the make. Quite often if one combination doesn't close or fails the no-go gauge, switching bolt heads (Mosin Nagant and Enfield) or complete bolts (Mauser types) will fix it. Obviously, you'd check them with a no-go gauge before firing them.

 

[troy fairweather]

maybe the cam surface on the bolt needs polishing.

 

[243winxb]

Could the extractor be needing some extra help snapping into the rounds extractor groove? Try some lube on the extractor.

 

[entropy]

maybe the cam surface on the bolt needs polishing.

That would be the last thing to try, sounds like it's something more than a mere polishing would cure. ACES&8S, you say you are mounting a scope. Take the scope and base off once and see if that doesn't cure it. If so, shorten the base mount screws, I don't know how many times I've mounted a scope with the screws provided and they were too long and dragged on the bolt. If it's just when you turn and lock it, the front one would be your first suspect.

 

[Bushpilot]

^^^^
Ditto what entropy said to check..

 

[Mr. Hill]

Yup you might have the end of a screw dragging on that bolt.

 

[Legionnaire]

I agree with entropy, who keyed on the fact that you are mounting a scope. I have had to shorten screws on a number of rifles.

 

[troy fairweather]

That would be the last thing to try, sounds like it's something more than a mere polishing would cure. ACES&8S, you say you are mounting a scope. Take the scope and base off once and see if that doesn't cure it. If so, shorten the base mount screws, I don't know how many times I've mounted a scope with the screws provided and they were too long and dragged on the bolt. If it's just when you turn and lock it, the front one would be your first suspect.

he said there where no marks on the bolt other wise that was the first thing on my mind

 

[Vern Humphrey]

Another consideration is the rifle may have a short throat. Measure several rounds and take the one with the greatest overall length. Coat the bullet with magic marker and chamber, then eject that round to see if there are any marks on the bullet.

 

[ACES&8S]

Sorry for my delay on reply, illness causes me lots of delays.
I will try these steps to see the culprit.
I already tried the scope mount screws by having to set higher rings on the rifle it crossed
my mind about previous experience with screws thru into the bolt travel route. Wish that was it but no.

 

[ACES&8S]

FOUND IT!
It was a sliver of brass from either the base or mouth of a case that embedded tight against
the top of a lug which I would never have found with a normal or even extensive cleaning.
You guys got me inside it after a good cleaning & looking with pen light & bore light which
resulted in using my dental tools to dislodge it. It was so formed inside the turn that the color
of it was all that gave it away.
After that she functions perfect.
Thanks AGAIN, I know my questions are way to many, but as far as results they provide me with
satisfaction every time.
I will try to look up my own answers more often but this place is perfect & allows real interest
instead of just internet facts. THANKS AGAIN.

 

[Legionnaire]

Glad you figured it out, and thanks for reporting back. Ask as many questions as you like. There are good folks here who enjoy a puzzle and helping a fellow enthusiast.