PTG one-piece bolt won't close

[DrPark]

Hi everyone,

I have a trued R700 action in .223 that I decided to get a .308 one-piece bolt for. It was a PTG bolt from Midway with an M16 extractor.

I'm running this bolt on a Remage switch-barrel setup but ran into the issue that this one-piece bolt will not close. From searching around it seems like the lugs may be too thick? Or is it an issue with the handle?

I plan on bringing it to a smith but I was wondering if this was a common issue.

 

[EWaugh]

I bought a new bolt from PTG for my Remington and it came with a piece of paper that stated to the effect the bolt may need to be fitted to your action. The lugs were over sized.

 

[carlsbad]

Yes, it is a common issue.

This is a common issue is the M-16 extractor, not the PTG bolt. I diagnosed that for a customer on the phone last week while I was at the driving range with my son. The lugs can't be too thick since this is a remage barrel and you can adjust where the barrel sits. The problem is with the M16 extractor. You should be able to close the bolt just fine without a round in it. The M-16 extractor has to extend outside the .700 diameter of the bolt. The standard tenon lip inside diameter on a Remington barrel is .705 or so. This dimension is kept tight as part of Remington's "3 rings of steel" safe design. For an M-16 extractor you have to open that dimension up a bit to give the extractor clearance. I think last week I got the bolt to fit with a few .001" of clearance at .720.

Now I like a tight fit here and that is one reason I'm not a big fan of M-16 extractors. I prefer the sako extractor which doesn't open as wide. It has gotten an undeserved bad rap when this dimension isn't kept tight enough allowing the extractor to escape during a case failure.

Lastly, if PTG has an ounce of customer service they would have made you aware of this. I'm pretty much done with them. My order received yesterday had a $15 "custom print" charge on it because the lady couldn't figure out how to enter the order. I'm still arguing with them over it. Add that to their ridiculous shipping and I should have just gone to JGS. I guess JGS can work off a PTG print. Since this was an old Dave Kiff design reamer, I tried to respect his intellectual property. But respect needs to go both ways. Rant off.

your smith will need to open that dimension up. Getting the barrel set up in the lathe will take longer than the machining job.

--Jerry

 

[DOGCAPPER]

I bought a PTG 223 bolt replacement for a 700 Rem running a 308 bolt face. the PTG had feathered edges on the lugs that required stoning off with a diamond whet stone. Not a big deal but my receiver is factory and would expect a looser fit. Works just fine but is a very tight fit.

 

[savagedasher]

And we wonder why gun smiths charge what they do. They deal with this problem all the time.
That doesn't help your problem . My suggestion is for you to find the tight spot . Then fix your self or take it to a gun smith .
Larry

 

[Preacher]

All the one piece bolts from PT&G need the lugs set back 99% of the time with that bolt on 700's.....

 

[gunsandgunsmithing]

All the one piece bolts from PT&G need the lugs set back 99% of the time with that bolt on 700's.....

This is why I only use the one piece version if I'm truing the action at the same time. IMHO, that's what this bolt is made for. IMO, barrels and actions should be machined to work with their bolt. Not the other way around. I've never had one, yet, that was a problem to use with a trued action. I've simply looked at the 1 piece bolts as an option only if truing the action. If not, the 2 piece makes more sense to me.

FWIW, I agree with everything Jerry said in regard to the 3 rings of steel and proper clearances. I've had a "worst case" scenario, where a ppc diameter case, on a 308 bolt face and a Sako extractor, experienced a severe over pressure load fired. No, the extractor didn't come out. I had a Pressure Trace hooked to the gun when it happened...It read 128,000PSI when it fired, too. The small primer pocket would allow a LRP to fall out, the case blew out at the extractor, the bolt nose expanded, as it should, to the counterbore of the barrel, the case was welded to the bolt face and the barrel had to come off to beat the bolt out of the action...but the extractor didn't come out. Point being...the 3 rings of steel work great as a safety mechanism but is easily and all too often compromised by too much clearance commonly being used at all critical surfaces. I feel sure that .720 is too much to rely on the principle design behind the 3 rings of steel. It was originally intended to be .003-.005" clearance at all surfaces.

 

[Dans40X]

Remove said barrel from receiver.
Take 2 measurements from receiver.
Measure from aft end of bolt lugs to fwd surface of handle.

If you need instructions on which measurements that are needed from the receiver-you need to seek a professional gunsmith & not a gun plumber.

 

[carlsbad]

This is why I only use the one piece version if I'm truing the action at the same time. IMHO, that's what this bolt is made for. IMO, barrels and actions should be machined to work with their bolt. Not the other way around. I've never had one, yet, that was a problem to use with a trued action. I've simply looked at the 1 piece bolts as an option only if truing the action. If not, the 2 piece makes more sense to me.

FWIW, I agree with everything Jerry said in regard to the 3 rings of steel and proper clearances. I've had a "worst case" scenario, where a ppc diameter case, on a 308 bolt face and a Sako extractor, experienced a severe over pressure load fired. No, the extractor didn't come out. I had a Pressure Trace hooked to the gun when it happened...It read 128,000PSI when it fired, too. The small primer pocket would allow a LRP to fall out, the case blew out at the extractor, the bolt nose expanded, as it should, to the counterbore of the barrel, the case was welded to the bolt face and the barrel had to come off to beat the bolt out of the action...but the extractor didn't come out. Point being...the 3 rings of steel work great as a safety mechanism but is easily and all too often compromised by too much clearance commonly being used at all critical surfaces. I feel sure that .720 is too much to rely on the principle design behind the 3 rings of steel. It was originally intended to be .003-.005" clearance at all surfaces.

I like what you say here. But many, many M-16 extractors are being installed on R700s and I bet most smiths open them up even wider. I just measured a barrel that was chambered by a well known gunsmith for M16 extractor and it was .722.

Quite the event you describe there. sounds like the pistol powder event that blew the savage into a 100 pieces. I've done some hoop stress calcs on the tenon region and chamber region and I like the remington design much better. The is probably why so many custom actions copy it (along with parts availability).

The OP has disappeared...but I think he's got what he needs if he read the thread.

--Jerry

 

[gunsandgunsmithing]

I like what you say here. But many, many M-16 extractors are being installed on R700s and I bet most smiths open them up even wider. I just measured a barrel that was chambered by a well known gunsmith for M16 extractor and it was .722.

Quite the event you describe there. sounds like the pistol powder event that blew the savage into a 100 pieces. I've done some hoop stress calcs on the tenon region and chamber region and I like the remington design much better. The is probably why so many custom actions copy it (along with parts availability).

The OP has disappeared...but I think he's got what he needs if he read the thread.

--Jerry

I forget which powders it was that I was loading. It was when I first designed the 30 Major(6.5 Grendel necked up) and was doing serious load development for a cartridge for which there was no data..coulda been 4227. It loves very fast rifle powders and slow pistol powders. Long story short...I had two powders out when the phone rang...You can figure out the rest. Stupid, dangerous and expensive mistake on my part. It made a big believer out of me, in not doing anything to compromise the original engineering behind the Remington 3 rings of steel design. FWIW, Remington doesnt hold proper tolerances on their own design, if what I read years ago was correct. That being that proper clearance at all bolt nose to barrel tenon areas be between .003"-.005". As with anything, add enough pressure and it'll fail, but with these clearances, the Sako extractor "couldn't" come out as it was captive.

 

[bigngreen]

The bolt is made to fit to the action, you could have a bolt nose recess issue or a length between the lus and bolt handle issue, it's made to turn the face of the bolt handle not the lugs.

 

[hoz53]

I like what you say here. But many, many M-16 extractors are being installed on R700s and I bet most smiths open them up even wider. I just measured a barrel that was chambered by a well known gunsmith for M16 extractor and it was .722.

Quite the event you describe there. sounds like the pistol powder event that blew the savage into a 100 pieces. I've done some hoop stress calcs on the tenon region and chamber region and I like the remington design much better. The is probably why so many custom actions copy it (along with parts availability).

The OP has disappeared...but I think he's got what he needs if he read the thread.

--Jerry

I wonder if the OP tried the assembled bolt in the action before he put the barrel on to start with. As has been said could be a number of things or multiple things causing this. How did he headspace the barrel ? Is it screwed to far into the action and the bolt nose hitting? Probably one of the things you guys mention but could be others. Thanks anyway to you guys as I've learned some things here to.

 

[Dans40X]

bigngreen-
it's made to turn the face of the bolt handle not the lugs.
(get a clue before posting BS)

NEGATIVE,NEGATIVE,NEGATIVE.

If you are smarter than the equipment that you are working on.

Remove said barrel from receiver.
1.Measure front receiver face to bolt handle cut.
2.Measure front receiver face to lug abutments.
Simple mathematics
Subtract #2 measurement from #1 measurement.

With bolt in hand, measure from aft end of bolt lug to fwd surface of bolt handle.

Face the aft end of bolt lugs to fit into action w/ approximately .008"-.010" clearance between fwd face of bolt handle & rear receiver ring.

Rocket science it is not.

 

[bigngreen]

bigngreen-
it's made to turn the face of the bolt handle not the lugs.
(get a clue before posting BS)

NEGATIVE,NEGATIVE,NEGATIVE.

If you are smarter than the equipment that you are working on.

Remove said barrel from receiver.
1.Measure front receiver face to bolt handle cut.
2.Measure front receiver face to lug abutments.
Simple mathematics
Subtract #2 measurement from #1 measurement.

With bolt in hand, measure from aft end of bolt lug to fwd surface of bolt handle.

Face the aft end of bolt lugs to fit into action w/ approximately .008"-.010" clearance between fwd face of bolt handle & rear receiver ring.

Rocket science it is not.

Your right it's not rocket science but when talking this over with Dave one day he said he set them up to turn the bolt hand face back to fit the bolt, I would much rather set back a bolt handle which has some wiggle room than start machining on a critical surface that is correct in the first place.

 

[Dans40X]

amazing!!

OP-
all I can say is, good luck!

 

[Eddie Harren]

Better'n the funny papers!

 

[gunsandgunsmithing]

I can see it working both ways. IME, the fit is very close as shipped, so it shouldn't be enough to severely affect primary extraction. In the case of removing a couple of thou from the handle face, it would add to primary extraction. Actually, when I read the post about it, I thought he was nuts but after thinking about it, I felt stupid for not having thought of it myself. What am I missing?

 

[bigngreen]

Kiff sells a little kit with a center and collars specifically for turning the front of the one piece bolt handle to fit to an action, takes way less time to make a small adjustment to a none critical surface than to set up, dial in then cut a critical surface. I can just pop a bolt in the three jaw trim the front of the bolt handle of, check it and make sure I like it then rally, far easier then taking measurements, setting up the bolt in a truing jig, dialing it in, especially with flutes, then cutting the back of the lugs, if you messed up your measurement and it's just a little snug still then you have to repeat the whole process. The only reason I started doing it this way was I called Kiff and was pissed, cause bolts were to snug, he then explained this to me, it works either way.

 

[butchlambert]

Kiff sells a little kit with a center and collars specifically for turning the front of the one piece bolt handle to fit to an action, takes way less time to make a small adjustment to a none critical surface than to set up, dial in then cut a critical surface. I can just pop a bolt in the three jaw trim the front of the bolt handle of, check it and make sure I like it then rally, far easier then taking measurements, setting up the bolt in a truing jig, dialing it in, especially with flutes, then cutting the back of the lugs, if you messed up your measurement and it's just a little snug still then you have to repeat the whole process. The only reason I started doing it this way was I called Kiff and was pissed, cause bolts were to snug, he then explained this to me, it works either way.

I'm a little confused?? Are you saying the bolt will not cycle until it is machined? This must also before a barrel is fitted to it? Tell me more.

 

[DrPark]

Apologies, I've been away for most of the weekend and didn't realize that my question would generate such a discussion.

In the end, I think it is a more mundane reason for the bolt not closing - the bolt body is slightly oversized, perhaps by 0.0015 and is binding when I am attempting to close it. The measurements (lug to handle) show that the bolt should fit. So now I think I need to polish down the diameter til it fits.