I have a bolt question, my rifle is a 308 Rem 700 action and a Pacific Tool Works one piece bolt. The action worked good with my old bolt, but the new one piece seem to be off on the bolt face. When I have a round in the chamber the bolt will close but it is extremely stiff, with out a round in the chamber it is very smooth. I did some measuring and then shaved .003 off the back of a empty case, then the bolt and action worked smooth again so I do not think it is in the Lug fitting. Do the pros here know if I should ream the barrel .003 or take it off the front of the bolt face with a lathe or am I going the wrong way?
Gunsmithing Rem 700 308 bolt issue, please help
- Thread starter solarflarearts
- Start date
Does the bolt close on a GO-gage? If yes, then it should chamber a factory new round. If you're having issues with handloads, then I would set the should back a couple more thousandths.
If it does not close on a GO-gage, then either that rifle becomes a handload only proposition and set the should back on your brass or run the reamer in or face the lugs until it closes on a GO-gage.
BTW the PTG bolts are not designed to be Drop-In headspaced.
If it does not close on a GO-gage, then either that rifle becomes a handload only proposition and set the should back on your brass or run the reamer in or face the lugs until it closes on a GO-gage.
BTW the PTG bolts are not designed to be Drop-In headspaced.
Last edited:
Thanks it it very tight on the GO-gage and dose not close on a NOGO-gage, I was using factory ammunition 4 different types. When I put a Snap practice round through it cycles fine. I was going to have the barrel reamed but then my older bolt will not work anymore as a backup.
i think they are very clear about their bolts not being direct drop-in replacements. they need to be fit. your headspace is too tight. other dimensions could very well be too tight too. personally, i'd have the barrel tenon and headspace set to the new bolt and get rid of your old bolt. you will never need it. ideally, fitting a new ptg bolt is best at the time of rebarrel.
a go gauge is a gauge. a snap cap is not. the stripped bolt should close with gravity on a go gauge. if it doesn't, you are too short.
Should be able to lap the lugs enough to fix it.
lap the lugs .003"?
that'll leave a nice flat and square surface on both the abutments and lugs....
Should gain .001 just getting both to engage. .002 should do it. Technique is everything.
You have 2 choices:
1) chamber barrel deeper
2) machine bolts lugs.......
were it I........ go with #1......
bill larson
1) chamber barrel deeper
2) machine bolts lugs.......
were it I........ go with #1......
bill larson
Thanks for all the advice.
BEFORE LAPPING SOMETHING:
if you're a handloader, bump down a little bit some of your brass shoulders , try the fit, and when your new bolt will close ok, call it a day_
( headspace values don't come from the Moshe's 12 stone tables, and the same rifle's firing&cycling,after some time,will help you anyway )
if you're not comfortable with that, you can ever considering the solutions advised above_
if you're a handloader, bump down a little bit some of your brass shoulders , try the fit, and when your new bolt will close ok, call it a day_
( headspace values don't come from the Moshe's 12 stone tables, and the same rifle's firing&cycling,after some time,will help you anyway )
if you're not comfortable with that, you can ever considering the solutions advised above_
Last edited:
and what happens if other dimensions are also too tight? what happens when you create convex/concave bolt lug and abutment surfaces? has the op checked the clearance between the bolt nose/counterbore, lug faces/breech end, bolt handle/receiver extraction cam?
you just spent good money on a good part. save the lapping for perfecting the surface finish between two machined parts that already fit, not replacing machining and/or opening up clearances.
and maybe i'm missing something, why would you want a bolt to "close stiffly" on a go gauge? why even use a gauge if you are going to ignore it? i could see just feeling a stripped bolt close on a go gauge but stiff? no thanks.
Last edited:
Dang Dude, I'm sure you're pretty smart. What other dimensions are we talking about? He said it closes fine cutting 3 off the case.
We've been through the bolt tilt issue and the top lug not contacting.
Even if the action has been trued (which I doubt it has) it is not likely the top lug contacts. Lapping can hardly induce a convex/concave situation. I would buy the idea of a taper. The only action that I am aware of that employs a taper is the 1917 Enfield. One of the strongest out there. I doubt, even if it was lapped incorrectly, it would pose a problem.
Closing tight on a go is a brass life thing. If you're not shooting crap ammo, why not have it tight? I've seen more factory ammo rattle under a bolt than close tight.
I totally agree. Lapping two surfaces that do not fit to start with takes a high spot on piece and makes a low spot on the other piece. It does not make anything flat as in full lug contact.
Have a qualified smith check the headspace and if needed, correctly face a few thousandths off the rear of the lugs. If it's more than a few thousandths then it's decision time- do you run a reamer in that doesn't match the original chamber or do you take more off the lugs which means sacrificing manual extraction on bolt lift? I don't think you have the knowledge needed to make an informed decision.
I can't say I've used any of the one piece units, but I've used 5 or 6 of the PTG bolt bodies. I agree with 300. Headspace isn't the only dimension that needs to be checked. You could have some contact with the end of the barrel shank or possibly the counterbore. Either of those two conditions can cause some pretty wacky shit to happen, as far as accuracy goes.
You guys are f'n scary. Big names that don't ensure both lugs contact in the cocked position? How do you accomplish that without lapping?
If .003" or 5 is sacrificial to extraction the world is coming to an end.
No need to challenge the OP's knowledge because he asked a question.
Are you just sayin' you don't lap lugs?
I do lap lugs.
The Op explained his problem but without further information and exploring the possibility of several other possible cures, the statement to just lap .003" off the lugs is premature at best and in my shop would not be considered best practices.
I suspect that we both agree that introducing a new bolt to the action would warrant lapping to get both lugs to contact.
My opinion is that it is pointless to check headspace before lapping is done.
That's one option for this Op. Without having a conversation with the man to determine exactly what he has, what path he has chosen to go down and why the journey, then how far he plans to travel down that path any work would premature. His whole problem may be as simple as a slight interference fit at the junction of the neck and shoulder which will go away on fire formed brass. Without asking the right questions there are no correct answers.
What about multicaliber/multibolt rifles?
Some questions don't need to be asked. It is very rare to see both lugs contact on a factory 700. The op's path is pretty well spelled out in his orig post. Fire forming would likely eliminate his problem with his current cases but it won't correct a short chamber issue.
Multi cal/bolt rifles are separate league. Done correctly each bolt is fitted and each chamber is headspaced to it.
Similar threads
