New barrel insufficient counterbore

[Chickentoast]

Just received a new barrel for a 700 w/ LRI short magnum bolt - M16 extractor, and she won't snap over the case head. I measured the counterbore and it's 0.71. I had requested 0.715, or to discuss if a different counterbore was recommended (figured the smith should know). So, question is whether I can buy and install a thinner extractor so that 0.71 would work, or if I need to send the barrel back.

I've already messaged the smith, but have yet to hear back. After waiting 4.5 months for the barrel, I was hoping to not have to send it back out into the abyss of time... Also, since it was done incorrectly the first time, I would like to figure out exactly how much counterbore I should request for this go-around, if I do send it back. Measuring with a caliper seems less that exact, since the extractor can pivot more than what's necessary to make it over the case. Anyone rebarrel with a short magnum LRI bolt know the minimum spec?

 

[AllenOne1]

What part of the chamber are you calling a counterbore? Are you using factory rounds to check the extractor or new unfired, unloaded brass?

 

[Chickentoast]

I have dummy rounds and new brass. I'm referring to the part of the barrel which corresponds to the 0.13" or so of bolt in front of the lugs. The bolt has a diameter of 0.7", but the M16 extractor increases that diameter when snapping over the case rim. Since that part of the barrel is 0.71, it does not have enough clearance to make it over the rim.

 

[spife7980]

What part of the chamber are you calling a counterbore? Are you using factory rounds to check the extractor or new unfired, unloaded brass?

Counter bore isnt part of the chamber... its the counter bore.

@Chickentoast if you requested it be .715 in your barrel order and it came back as not that then Id send it back to the smith and tell them to fix their fuck up and quick or to give me my money for the whole thing back. Counterbore is one of those too much doesnt hurt a thing and too little makes it nonfunctional so I see zero reason for skimping on that dimension.
That said, .710 usually would be adequate on a factory rem so Id make sure you had the request in writing first.

Calipers is fine for measuring that. Might be able to file on the extractor a smidge too so itll fit.

 

[Chickentoast]

Counter bore isnt part of the chamber... its the counter bore.

@Chickentoast if you requested it be .715 in your barrel order and it came back as not that then Id send it back to the smith and tell them to fix their fuck up and quick or to give me my money for the whole thing back. Counterbore is one of those too much doesnt hurt a thing and too little makes it nonfunctional so I see zero reason for skimping on that dimension.
That said, .710 usually would be adequate on a factory rem so Id make sure you had the request in writing first.

Calipers is fine for measuring that. Might be able to file on the extractor a smidge too so itll fit.

Thanks, yes I have it in writing: "I have an upgraded bolt with M16 extractor. Please counterbore .715 to accomodate. If you normally do something else for M16 extractor, please just give me a call (xxx) xxx-xxxx. Thanks!"

I'm going to try and estimate how much more counterbore I need - hoping to file the extractor instead - sucker is thick... any worry about the integrity/strength if I file it down?

As an aside, if this were a thread about what color camo I should get, it would be 34 pages by now.

 

[BuildingConceptsllc]

Thanks, yes I have it in writing: "I have an upgraded bolt with M16 extractor. Please counterbore .715 to accomodate. If you normally do something else for M16 extractor, please just give me a call (xxx) xxx-xxxx. Thanks!"

I'm going to try and estimate how much more counterbore I need - hoping to file the extractor instead - sucker is thick... any worry about the integrity/strength if I file it down?

As an aside, if this were a thread about what color camo I should get, it would be 34 pages by now.

Seems to me you should be able to just say "it won't extract".... fix it. But, you may br right in stating an exact amount I guess. I would think the fact that it won't extract is sufficient evidence that it needs to be corrected and done so quickly. If it's a reputable guy, that shouldn't be an issue.

 

[Chickentoast]

Seems to me you should be able to just say "it won't extract".... fix it. But, you may br right in stating an exact amount I guess. I would think the fact that it won't extract is sufficient evidence that it needs to be corrected and done so quickly. If it's a reputable guy, that shouldn't be an issue.

Yes, I'm sure he'd fix it - just don't know how long that will take, and prefer to go an easier route like buying a thin extractor or filing mine down - if there is no downside. I've searched inconclusively, and don't have the experience to have seen the issue before. It has only been a day since I emailed him, so not going to call until after Easter.

 

[Ksracer]

I'm not sure that .005 will be the difference between functioning and not.

You should be able to ESTIMATE the needed counterbore by measuring the radial thickness of the extractor from the hook to the outside, multiplying the thickness X2 and adding it to the diameter of your case rim. Add another .015 for clearance.

Or just call LRI and ask...

 

[Average guy]

Honestly any competent machine shop should be able to open the counter bore in an hour tops, if you are worried about turn around time. I’d see what the smith says.

 

[BuildingConceptsllc]

Yes, I'm sure he'd fix it - just don't know how long that will take, and prefer to go an easier route like buying a thin extractor or filing mine down - if there is no downside. I've searched inconclusively, and don't have the experience to have seen the issue before. It has only been a day since I emailed him, so not going to call until after Easter.

Just politely but firmly ask him when you could expect it to be corrected by? If that answer doesn't work, then say "well I've waited for 4.5 months to get the barrel and now have to send it back, so don't you think it's fair that this gets moved to the very front of the line and fixed and sent back to me in a weeks time?"

It's definitely not an issue of how long it takes to do it, so the place in line is the only question, and since it's their mistake, it's quite normal for that correction to be first and foremost, especially with something he himself can fix and do so in less than 10 min.

 

[Ksracer]

Was this a prefit? I'm assuming not since it's a 700, unless it's a remage.

 

[Chickentoast]

Was this a prefit? I'm assuming not since it's a 700, unless it's a remage.

Yes, prefit, not a remage - one of the few doing 700's without a nut.

 

[Ksracer]

Yes, prefit, not a remage - one of the few doing 700's without a nut.

That's the first I've heard of that. 700's tend to have a range of headspace measurements from the factory, throw in an aftermarket bolt and a recoil lug and I'm not sure how you would determine the headspace spec without the action in hand. I'd be curious to know how it works out.

 

[dimar1492]

Just to confirm, the bolt cycles without interference when not engaging a round?

 

[Chickentoast]

I have not installed the barrel, but yes, the bolt is fine. I have a few different recoil lugs, so will see where she's at when I do install, and adjust if necessary. Remington used different recoil lugs to compensate for their lack consistency back in the day. Mine is an RR, so not "old", but I can't check it unless the bolt snaps over the case head

 

[AllenOne1]

Can't you just clip the case to the bolt and push it into the barrel rather than making it click over the case rim inside the counterbore area?

 

[Chickentoast]

Can't you just clip the case to the bolt and push it into the barrel rather than making it click over the case rim inside the counterbore area?

Yes, that works fine, bolt is GTG.

 

[AllenOne1]

Yes, that works fine, bolt is GTG.

So you could verify head space prior to sending it back just incase you have a second issue that needs to be addressed.

 

[fdkay]

Did you make sure the smith understood you were talking about ID of the counter bore and not depth?

 

[Terry Cross]

Just received a new barrel for a 700 w/ LRI short magnum bolt - M16 extractor, and she won't snap over the case head. I measured the counterbore and it's 0.71. I had requested 0.715,

Question: Where did you come up with the 0.715" dimension in the first place?

Anyone rebarrel with a short magnum LRI bolt know the minimum spec?

Stop and think about this....
Why would you ask a forum and chance a wrong answer when you already are an LRI customer?

Asking your barrel supplier to recommend the correct counterbore for a 3rd party bolt mod is out of bounds. It should not be on them to take on that responsibility.

As @Ksracer mentioned, you need to think twice about your 0.715" mandate.
If you return the barrel or have a 3rd party take you from 0.710" to 0.715", you still may not have the necessary clearance.

Increasing the diameter by 0.005" (if your 0.710" measurement is accurate) will only give you 0.0025" more clearance for the extractor to pivot.
If your barrel supplier accommodates your request and it still does not function with complete clearance, where would that put you in resolving this?

You mentioned that the barrel was a "Pre-fit".
Just like a previous post above, I would be skeptical about a Pre-fit for a Rem 700. Even the RR Serial Numbers are not consistent not to mention their shitty recoil lugs being all over the place as well. WAY, WAY lots of room to be wrong on a PreFit shouldered barrel for Rem700.
Headspace gauges FOR SURE.

Another observation, . . .
The moment you started spec'ing any dimension change from a stock pre-fit, you are torpedoing the maker's intent of a Pre-fit.

Another observation, . . . .
I disagree with going back to the barrel supplier and putting the "It won't extract. Fix it" thing on his back.
This situation is a pitfall of sourcing separate parts from separate suppliers while at the same time requesting non-standard changes on dimensions that you aren't even in possession of.


My 2 cents could be to stop everything.
Contact LRI in writing and request their recommended counterbore dia.
If they recommend more than 0.715" counterbore (and I bet they do), you were most certainly on the wrong trail to begin with.
PAY someone to open the counterbore of your "Pre-fit" barrel to LRI's recommended dim then go wear this barrel out (AFTER CHECKING THE HEADSPACE)


./

 

[Ksracer]

@Terry Cross Well said. This was a recipe for failure from the start on both parties. The OP should have given better info and the smith never should have taken the job without asking more questions and having the action in hand.

 

[Chickentoast]

Question: Where did you come up with the 0.715" dimension in the first place?


Stop and think about this....
Why would you ask a forum and chance a wrong answer when you already are an LRI customer?

Asking your barrel supplier to recommend the correct counterbore for a 3rd party bolt mod is out of bounds. It should not be on them to take on that responsibility.

As @Ksracer mentioned, you need to think twice about your 0.715" mandate.
If you return the barrel or have a 3rd party take you from 0.710" to 0.715", you still may not have the necessary clearance.

Increasing the diameter by 0.005" (if your 0.710" measurement is accurate) will only give you 0.0025" more clearance for the extractor to pivot.
If your barrel supplier accommodates your request and it still does not function with complete clearance, where would that put you in resolving this?

You mentioned that the barrel was a "Pre-fit".
Just like a previous post above, I would be skeptical about a Pre-fit for a Rem 700. Even the RR Serial Numbers are not consistent not to mention their shitty recoil lugs being all over the place as well. WAY, WAY lots of room to be wrong on a PreFit shouldered barrel for Rem700.
Headspace gauges FOR SURE.

Another observation, . . .
The moment you started spec'ing any dimension change from a stock pre-fit, you are torpedoing the maker's intent of a Pre-fit.

Another observation, . . . .
I disagree with going back to the barrel supplier and putting the "It won't extract. Fix it" thing on his back.
This situation is a pitfall of sourcing separate parts from separate suppliers while requesting non-standard changes on dimensions that you aren't even in possession of.


My 2 cents could be to stop everything.
Contact LRI in writing and request their recommended counterbore dia.
If they recommend more than 0.715" counterbore (and I bet they do), you were most certainly on the wrong trail to begin with.
PAY someone to open the counterbore of your "Pre-fit" barrel to LRI's recommended dim then go wear this barrel out (AFTER CHECKING THE HEADSPACE)


./

Again, what I wrote to smith: "I have an upgraded bolt with M16 extractor. Please counterbore .715 to accommodate. If you normally do something else for M16 extractor, please just give me a call (xxx) xxx-xxxx. Thanks!"

I don't see this as a huge deal, we all screw up - I bet the smith just didn't read my note. The 2 original questions I asked here were: can I buy a thinner extractor so I don't have to send it back, and does anyone know the proper counterbore from experience.

Of course I have headspace gauges, and already posted that I have a few different recoil lugs to do some trial and error if it isn't where I want it. I also expected a call from the smith to discuss counterbore, as I've read up to 0.785 as recommended. This is not a big deal, nor should it be rocket science. If he didn't read my note, and wants to charge for a custom counterbore, I also have no problem with that.

 

[Chickentoast]

@Terry Cross Well said. This was a recipe for failure from the start on both parties. The OP should have given better info and the smith never should have taken the job without asking more questions and having the action in hand.

Better info? I sent a spec and it wasn't followed. That's it. And I'm not bashing the smith for it - we all screw up, probably just an oversight.

 

[Skeptic1]

Terry Cross is one of the best there is. I'd read his response again.

 

[Chickentoast]

Thread getting really gay, really quickly.

For those searching in the future, I talked to LRI, and they said they run 0.75 counterbore. I will be sending my barrel back to get it opened up, but will check headspace first, to make sure I don't have a 2ndary issue.

 

[Chickentoast]

Update: Barrel is back and installed, 0.75 counterbore works perfectly. Headspace was also perfect on a shouldered 700 prefit - my action is an RR from a Gen1 5R.