Remington bolt nose to barrel longitudinal clearance?

B

Boyd Allen

Active member
A friend, who fits his own barrels, has been plagued with fliers on a match grade barrel, chambered in .204 Ruger.
At my suggestion he checked the clearance between the end of the bolt nose and the bottom of the counter bore in the back of the barrel. It is no more than .001. In your experience, could this be the cause of his problem, and what should this clearance be?
 
Boyd

I'd treat that particular clearance in a 700 just like any other action - .005" to .010".

Now, as to the side clearance, i'm still a believer in "no clearance needed", but you didn't ask about that, did you? :rolleyes:

Ray
 
Boyd Allen said:
A friend, who fits his own barrels, has been plagued with fliers on a match grade barrel, chambered in .204 Ruger.
At my suggestion he checked the clearance between the end of the bolt nose and the bottom of the counter bore in the back of the barrel. It is no more than .001. In your experience, could this be the cause of his problem, and what should this clearance be?
Click to expand...

I agree with Ray, i try for .005 bolt to barrel ,no side clearance.
 
Correct me if I'm wrong but, clearance is just that, clearance.

I think .005"-.010" is a good target for clearance. I cut my bolt nose recess in the barrel to a depth of .006"-.008" deeper than needed for the bolt to close. When the barrel is tightened, I'm hoping for .005-.007" over all clearance. The diameter of the recess is cut to .706". I've used the PTG bolt and the standard Remington bolts, no problems. It seems that if there were contact between the barrel and bolt there would be an issue.
 
here is the only problem.

Remington Actions are notorious about not being very true, especially the reciever threads. Just looking at how off center many of the firing pin strikes are on non modified actions can give a clue as to how bad things can be.
When I do a Remington. I try to give it about .005 clearance on the length, and the same on the diameter fit.
Most Benchrest Shooters consider any contact between the bolt and the barrel to be an accuracy killer. Not sure how true this is, but many believe it to be so.
Keep in mind, if you are going to get real tight with tolerances, then everything should be truely straight. If you are dealing with a action that has been trued by a competent craftsman, then you can tighten things up.
The expression "clearance is clearance" is correct. The only time you can run into trouble is with the counterbore being too deep with cases such as the 6BR. There is not a lot of metal thickness in the web, make the counterbore too deep, and you can uncover the solid portion of the case, which can lead to a blown case head.........jackie
 
I have a bad habit that is hard to overcome. I seem to make the same mistake over and over. Being as how this a Benchrest Forum, I always assume that my answers automatically include the understanding that everything is straight and true and that there is little need for things such as "clearances" to accomodate sloppy work.

My comment about side clearance for the Rem 700 bolt nose was with the assumption that the action and bolt was straight and true, that the barrel tenon, counterbore, and chamber were likewise. If they are, there is little need for any side clearance.

No offense intended wnroscoe, but when I hear guys say that "...It seems that if there were contact between the barrel and bolt there would be an issue. . ." I have to ask, "Who said so?" I like the way Jackie put it. ". . .Not sure how true this is, but many believe it to be so. . ."

I know some very good shooters/gunsmiths who agree with me (that's where I got the concept in the first place) and I've done all of my Rem 700 re-works that way. They all shoot better than I can. If anyone can show me how they would shoot better with more clearances, I'll chuck them up tonight and open the counterbore. Just tell me how much, and why.

JMHO

Ray
 
On my own Remingtons, I fit with .005+ end play. For the side clearance, I used to fit with no more than a couple tenths clearance. A few years back I started cutting the counterbore for .0025 clearance and grooving the counterbore for a teflon O-ring with about .005 compression. Does it work better? Probably not but I kind of like the concept! Regards, Bill.
 
I agree 99.99% and

Cheechako said:
I have a bad habit that is hard to overcome. I seem to make the same mistake over and over. Being as how this a Benchrest Forum, I always assume that my answers automatically include the understanding that everything is straight and true and that there is little need for things such as "clearances" to accomodate sloppy work.

My comment about side clearance for the Rem 700 bolt nose was with the assumption that the action and bolt was straight and true, that the barrel tenon, counterbore, and chamber were likewise. If they are, there is little need for any side clearance.

Ray
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If I was to shoot in a "sterile" benchrest environment I'ld stepped it up to agree 100%.

Shoot better
Peter
 
Peter

This IS a Benchrest Forum so I automatically assume we shoot in a clean environment. But, once again, maybe I am taking too much for granted.

Call me a snob if you want, but just for the record, I have little respect, or symathy, for shooters who insist on shooting dirty rifles. :(

Bill

Dittoes! :)

Ray
 
Cheechako said:
No offense intended wnroscoe, but when I hear guys say that "...It seems that if there were contact between the barrel and bolt there would be an issue. . ." I have to ask, "Who said so?" I like the way Jackie put it. ". . .Not sure how true this is, but many believe it to be so. . ."
Click to expand...

So, zero clearance would be fine with you?? I'll take a little though, just to be on the safe side.

I love it when someone says "No Offense intended" or "Don’t Take this the wrong way" or "I don’t mean anything by this, but"

I never said it was gospel, I was just giving my .02 worth.

Non Taken Ray ;)
 
nroscoe

Like Bill, I've fitted the bolt nose with less than .0005" clearance and they slide in and lock up like they're made of grease. That's not zero, but still pretty close and straight. :D

Ray
 
Cheechako said:
nroscoe

Like Bill, I've fitted the bolt nose with less than .0005" clearance and they slide in and lock up like they're made of grease. That's not zero, but still pretty close and straight. :D

Ray
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Sounds like clearance to me, not much but, still clearance.
 
Ray this time I agree 100%

However where I shoot and what I shoot, I can't help to have a swirl of wind to throw me an action "full" of sand from time to time, but I can hope to minimize the sand effect by running a 0.005" side/depth nose play.

The clearence is for and to suit my shooting conditions and I'm not to justify or defend whether the 0.005" clearence is good or bad for accuracy.

Even on this forum there would be quiet few of those who shoot and know about shooting far more then I'll ever know and they're shooting in your clean environment and are running side/depth tolerances which are so generous, that I wouldn't even care to think of.

Shoot better
Peter
 
Last edited by a moderator:
Boyd Allen said:
A friend, who fits his own barrels, has been plagued with fliers on a match grade barrel, chambered in .204 Ruger.
At my suggestion he checked the clearance between the end of the bolt nose and the bottom of the counter bore in the back of the barrel. It is no more than .001. In your experience, could this be the cause of his problem, and what should this clearance be?
Click to expand...
Most Rem 700's I've checked have about 0.010" end clearance and 0.006" on the diameter, (that is 0.003"/side on the bolt nose). A sheet of 20# printer paper is 0.003".

According to the application, if it were hunting/varmint, I'd put about the factory clearance. If the shooter reloads, there will be some time that powder gets dumped in the chamber. In the field, taking the barrel off a Rem 700 to clean the powder out and getting the recoil lug back where it should be is a B****.

For semi-benchrest application, I'd still go with factory clearances. In the semi-benchrest situation, many shots, much gunk, many jams.

Why some think that 0.010" clearance is going to hurt accuracy is a mystery to me. It sure is not going to be a safety issue. Moving back 0.010" on the brass web still puts the cartridge head solid part way up into the chamber. On the old balloon-head cases, maybe, but how long has that been (except for the Sako 220 Russian cases if the late '80's).
 
Thanks guys. I have passed on the information. He is going to change this one thing, and retest. I will let you know if the flier problem goes away.
Boyd
 
How to accurately measure bolt nose clearances?

I'm about to do my first Rem. 700 short action in .308 (standard) and was wondering how to best take these measurements?...Can someone please walk me through it quickly?


Thanks


1911
 
1911 said:
I'm about to do my first Rem. 700 short action in .308 (standard) and was wondering how to best take these measurements?...Can someone please walk me through it quickly?


Thanks


1911
Click to expand...

Use lead solder wire or plastigage attached to bolt nose using a heavy grease binder, cam bolt to barrel counterbore to squeeze wire/plastigage, take measurement of squeezed wire/plastigage to get clearance measurement figures....................Don
 
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