A few questions

K

kapac

Guest
Hey fellas, been lurking in here for some time and have only posted a few times. I have been trying to get some machines and tooling and have accomplished most of that (to start).

So here is a question, I have a Rem. LA that I will be truing up and I have not ordered a barrel yet but will in the next few days. I had the action out looking it over and seen a thread relief cut inside the action. So can I put a thread relief on the tenon as well? If not, why?

Another question is recoil lug to tenon fit what kind of fit am I looking at? I was thinking like a thou. slip fit? More or should be a slight press fit? Please give explanation.

Thanks for your help, I await your responses.

Kapac
 
Could you elaborate on the thread relief found inside the receiver (you said action but I am thinking receiver)? I am not following you here.
 
The recoil lug should turn freely on the barrel shank... it allows you to line the recoil lug up easier. If I am adding an after market recoil lug I like the Holland lugs... not too thick and the same diameter as the action and they look real good installed. The factory 700 lugs will work fine, despite not being machined to the 10 thousands of an inch. I don't think anyone has documented an accuracy gain by using a fancier lug.... at least I have not seen it.

The thread on the barrel shank can follow through under the lug area so a relief cut is not required in the action nor on the barrel. Some prefer to cut a relief on the barrel. It doesn't matter which way you prefer to do it...
 
Ok... the "receiver" has a thread relief (inside) as in all Rem. actions (receivers). So the question is "What is the reason for not having a thread relief on the tenon"? Or can you put a thread relief on the tenon? If not, why?

And the question still remains for the recoil lug.
 
Dennis

I'm trying to follow what are you describing here and if I can see the right picture it seems to me like if some accuracy conscious freak used the inside thread relieve to center the barrel as it's done in many other accuracy orientated actions. That would be the most logical explanation, to me anyway. Practically one would think that it will help to center the barrel and improve the accuracy. Since the relieve is already there use it to your advantage.

Shoot well
Peter
 
PPP MMM said:
I'm trying to follow what are you describing here and if I can see the right picture it seems to me like if some accuracy conscious freak used the inside thread relieve to center the barrel as it's done in many other accuracy orientated actions. That would be the most logical explanation, to me anyway. Practically one would think that it will help to center the barrel and improve the accuracy. Since the relieve is already there use it to your advantage.

Shoot well
Peter
Click to expand...

The inherent design of 60 degree V threads automatically aligns the barrel thread with the action thread. I don't think it is very common to machine shoulders and diameters to try and assist in centering the assembly... I think the majority of the top Benchrest shooters use accurately fitted 60 degree V threads with a flat action face and a flat shoulder on the barrel... and I also think they are the most accuracy conscious freaks around... :D

Usually relief cuts in actions and on barrel tenons are so you do not get thread interference when you can not physically thread completely up to a shoulder.... Mauser 98's as an example.
 
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Kapac

FWIW, IMHO, a relief cut on the tenon, at the shoulder, does nothing one way or tuther as far as accuracy is concerned.

On the up-side, it does give you room to disengage the half nuts without running into the shoulder which, in turn, results in a slightly lower pucker factor.

On the down-side, if you ever want to set the barrel back it could place that cut right in the middle of the new thread. But I haven't found that to make any difference either. Just don't let your buddies see it.

Again, JMHO

Ray
 
kapac said:
Ok... the "receiver" has a thread relief (inside) as in all Rem. actions (receivers).
Click to expand...
I've looked and and felt the threads in many Remington actions and have not seen a thread relief. The threads appear to be milled or tapped. There is no need for a relief, the barrel does not need threads much deeper than 3/4". Am I totally missing something here???? Are you saying that receivers have the first thread or so removed?
Yes, I realize that a small relief helps when re-cutting the threads but nothing more than a "v" that is a bit deeper than .032 per side is required. Starting the cut at the "v" and coming out with the threading tool works best.
We all have opinions.
 
Jay

I have seen M700 actions with and without a relief cut. The only bare action I have available right now has one about .075" deep but, to be honest, I may have put it there myself, I don't remember. When I true a receiver I usually clean up the beginning of the threads in just that way. The Pandas have a very big relief cut and George Kelbly used to also put a big relief cut on his barrels back when he was making a lot of them.

I really don't see that it's a big deal. If you like to cut the tenon threads without a relief it does help to have a slight relief inside the receiver.

Ray
 
Dennis

You'r right that the squarenest of the contact shoulder makes the important joint, however all my actions are relieved by 3mm deep and the barrels are left with 2.5mm solid portion of the tread shank. That portion is 0.01mm or 0.00393" undersize. I'm my not be an accuracy freak fanatic but my inhereted nature always makes me to do everything as good as it possibly can be. I can be sure that if there is a movement that movement can only be 0.01mm or less and that gives me far more confidence than to relly purely on the fitted thread alone. I've never done it, but if one could measure a thread of an action where the thread runs to the end I wouldn't be slightest surprise if the part of the first thread would be lifted up and crushed back against the barrel shoulder. Just my 2c worth.

Shoot well
Peter
 
That has answered my questions (I think)?

Jay, yes... that is what I am saying. This is a brand new action I just pulled off and it has a relief cut just as you say, the first few threads.

Dennis, last sentence is the same idea I was speaking of. Oh and thanks for clarifying the recoil lug.

The reason for the thread relief on the tenon was just as Cheechako describes as the pucker factor.

PPP, I like your thinking!!

Thanks for the help fellas!
Kapac
 
PPP MMM said:
You'r right that the squarenest of the contact shoulder makes the important joint
Click to expand...

Wrong,

Dennis said: "The inherent design of 60 degree V threads automatically aligns the barrel thread with the action thread. I don't think it is very common to machine shoulders and diameters to try and assist in centering the assembly... I think the majority of the top Benchrest shooters use accurately fitted 60 degree V threads with a flat action face and a flat shoulder on the barrel"

and he is correct, it is the "threads" that do all the centering work, assisted by the action face and flat shoulder in making a true and correct joint.

Anyone who has trued actions sees proof of this joint correction every time..........Don
 
Misconceptions

Most of those that insist on creating solutions to problems that do not exist do so because they are ignorant of the originol concept's function.
A properly fitted, and tightened, 60 degree thread joint is all that is needed to secure a barrel with 100 percent efficiency.
Now, I did qualify this statement with "properly fitted and tightened". Many of these "fixes" that are thought up are generally the result of one of these two functions being poorly performed..............jackie
 
Jackie

Let's put it simply if a perfectly square tightly fitted 60V thread with square shoulder on both contact parts will automaticaly center the barrel the extra relieve in the the receiver and tightly 0.01 mm fitted solid shank of the barrel won't do any harm. That way at least one knows exactly what he is dealing with. Any competent machinist should know that every thread will pull once tightened up.

Shoot well
Peter
 
Let's revisit this "thread relief" again. I believe he stated that it was at the "first thread"? To me this would imply the thread relief is at the front or beginning of the thread in the receiver. I have taken apart a bunch of Remington receivers and have never found a thread relief on the inside of one. They are all cut with a tap and no thread relief is needed. It may be that someone earlier had cut one in there to facilitate rethreading the receiver in reverse,from inside out. Am I missing something here?
 
Jkob said:
Let's revisit this "thread relief" again. I believe he stated that it was at the "first thread"? To me this would imply the thread relief is at the front or beginning of the thread in the receiver. I have taken apart a bunch of Remington receivers and have never found a thread relief on the inside of one. They are all cut with a tap and no thread relief is needed. It may be that someone earlier had cut one in there to facilitate rethreading the receiver in reverse,from inside out. Am I missing something here?
Click to expand...

I agree with you - factory actions are not relieved.

I have cut a relief (when rethreading actions) just removing the thread for about 60 thou in length, so in the future there would be an easy measurement for the not standard thread diameter... but I have never seen a Remington 700 action relieved from the factory.
 
jkob

I don't think anyone has suggested that there is a factory relief cut deep inside the receiver, close the lug abutments. Any such cut would have been made as part of a truing process, as you suggested. Like Dennis, I do make a very light cleanup cut at the receiver face. But, there are actions, such as the Panda, that have a very long factory made relief cut at the action face.

I said it earlier, and I will say it again, this is all a lot to do about nothing, IMHO.

Ray
 
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And I agree withthe both of you. To my way of thinking, the "relief" would be at the end of the thread to allow a spot for the tool to stop to relieve the pucker pactor. I also cut a "counterbore" as I call it in the beginning of the thread to assist it measuring the major diameter of the tenon.

Thanks

Jim
 
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