?To nut or not to nut?

[Pdvdh]

+1

The Nut is not for accuracy but for ease of assembly.

This post has drifted in all directions but by now I'm sure the original poster has his answer.

J E CUSTOM

I think bigngreen knew where he was headed with his own rifle at least one week ago. Rumor is his Savage nut will be posted in the classifieds. From the Posts within this Thread, there should be quite the demand. Might be able to purchase the custom barrel with the proceeds from one of these nuts. Ouch

 

[Trickymissfit]

Wow. Now you've cleared it all up for all of our readers with your condescending response. That'll gain you a lot of credibility. Most people that truly know what they're talking about are able to explain it. Maybe you know what you're talking about. You're definitely not explaining it in any manner the majority could understand. You're jumping around to non-relevant items, as if you feel the need to provide us with the credentials of your understandings of all theoretical aspects of mechanics, physics, and the art of marksmanship. Where's the focus on the subject of this Thread? Which is a barrel nut.

I follow your discussion on two different barrel lengths. What's it got to do with whether a NUT is or isn't used. The same issues apply to the mega-long barrel versus a short barrel whether the nut is used in mounting the barrel to the action or not.

You've talked about the benefits to the nut when it comes to stretching the threads so that the threads on the barrel tenon make better (fuller) contact with the threads in the action. This is the second time I've asked this. What difference does it make if the force used to create the tensile force between the action threads and the barrel threads is the nut on an extended threaded barrel tenon, or the shoulder of the barrel at the end of the threaded tenon? Either system is acting to pull the threaded tenon back out of the threaded action. Where's the magic in using a nut to create this force versus the use of the shoulder on the barrel itself? How do the threads know whether the tension they're experiencing is due to the shoulder on the barrel, or a NUT?

How does the tensile force from the use of the nut improve the percentage of action/barrel thread contact compared to the use of the shoulder at the end of the threaded tenon on the barrel, provided that equal quality threads have been cut in both examples. That explanation cannot be so difficult that you're unable to articulate it?

talk about the pot calling the kettle black!

There was a small error in your post that really needs to be rectified. The reason the thread would normally be put in a stretched position is to make it strait and stress it to the point that it is ridgid. In otherwords your stressing the thread to create a condition that in this case is conductive to ridgitity. The practice is not new, and is rather common in the machine tool industry as well as super precision gauging. The stretched thread here just happens to be there, and to the shooter's benifit.. Once again full contact of any thread is impossible, and cannot see any argument there. But to make the first series of threads come into contact with the female as well as the last set puts you a leg up. And then to literally force things together under a predetermined stress just helps the situation.

** the nut is under compression once it's put under torque. The barrel threads are stressed, and tus stretched to make full contact. If you had read my previous posts with an open mind you'd have picked up on the fact. Not alot of stress, but enough to matter. When you seat the shoulder, you really have no accurate way of controlling thread contact. Certainly you are tight at the shoulder, but are you tight 1/2" into the thread? Even a quarter inch into the thread? You just don't know and your guessing. There is no guess in a stretched thread; otherwise nobody would bother to use the concept. You once spoke of a 95% thread contact, and I'll give you that. Have you ever calculated the stated clearence. Kinda scarey isn't it? I suspect you really talking something like 99% or better, and I suspect it was just hitting the wrong key that day. But it dosn't matter anyway. You stated you don't have 100% thread contact. A thread with 99.5% contact will still have about .005" clearence on a 1.050-20 thread, but I guess you could be very carefull and get the end play down to about .0025. So yet get it down to .0025", and manage to thread the parts together without damage to the thread form. You got a near perfect thread going into a near perfect female thread (we all know better than that). After the shoulder is seated and maybe has 120 ft. lb. of torque (bringing in an undiscussed problem); how does one secure the barrel thread in the action? Or better said how does one controll what goes on inside the reciever bridge? You have no controll, and only hope for the best! In otherwords you probably have a half inch of barrel thread hanging out there doing nothing.
gary

 

[Pdvdh]

talk about the pot calling the kettle black!

**There was a small error in your post that really needs to be rectified.

If you had read my previous posts with an open mind you'd have picked up on the fact.

You once spoke of a 95% thread contact, and I'll give you that. Have you ever calculated the stated clearence. Kinda scarey isn't it? I suspect you really talking something like 99% or better, and I suspect it was just hitting the wrong key that day. But it dosn't matter anyway. You stated you don't have 100% thread contact. A thread with 99.5% contact will still have about .005" clearence on a 1.050-20 thread, but I guess you could be very carefull and get the end play down to about .0025. So yet get it down to .0025", and manage to thread the parts together without damage to the thread form. You got a near perfect thread going into a near perfect female thread (we all know better than that). After the shoulder is seated and maybe has 120 ft. lb. of torque (bringing in an undiscussed problem); how does one secure the barrel thread in the action? Or better said how does one controll what goes on inside the reciever bridge? You have no controll, and only hope for the best! In otherwords you probably have a half inch of barrel thread hanging out there doing nothing.
gary

TM,
I'm looking to understand the concept behind your contention that the barrel nut will set the threads on the tenon to the threads within the action in a manner that will yield better accuracy from a rifle. Simple as that. If you are able to explain it, I'm open to your discussion - no matter what color you place on the kettle.

A point of clarification: I never specified a magnitude of any percentage of thread contact in any of my previous posts. You may be confusing my posts with those of another Forum member or members.

I'm not following the "small error in my post that needs to be rectified". You could be right, but I don't know what error you speak of so I can't really work with that and respond.

The use of the nut makes the nut an additional contact face in the assembly of the barreled action, and a key part in maintaining the concentricity within the barreled action assembly. I can understand that with the use of a nut, the threads are positioned within the barreled action first, and then placed under tensile force with the use of the nut without any further turning of the barrel threads into the action threads. The thread contact surfaces can remain stationary while the nut is tightened down. But tightening the nut down to generate the tension force on the barreled action places the nut thread to barrel thread contact in the same situation the barrel threads and action threads are placed under if the barrel is threaded into the action and tightened against the shoulder without the use of the nut. The threads are being turned (the contact surfaces are rotating) at the same time the tightening torque is being developed. So if that's a bad thing for the barrel thread to action thread fitment while torquing (tightening) of a non-nutted barreled action, it should likewise be a bad thing for the nut thread to barrel thread fitment when the Savage-style nut is torqued down.

Your contention that the use of the nut is a more controlled method of placing the barreled action thread assembly under tension seems to have merit. But your contention that the method will improve the accuracy of a rifle is up in the air. It seems to have neglected the inclusion of an additional set of threads (nut to extended barrel tenon threads) that have to be precisely cut and the additional mating surface of the face of the nut to the face of the action. I'm not a machinist, but I can envision that squaring up the face of a threaded nut in a lathe so that the action mating face is exactly perpendicular to the thru-bore of the threads in the nut is a headache - compared to squaring up the shoulder on a 20" plus long barrel that can be easily chucked up in the lathe. But I'm sure a good machinist would find a way.

I do appreciate your effort to explain yourself. Perhaps its just me. The jump from employing the barrel nut to improved accuracy is getting lost in the fog.

I can fully appreciate the ease with which barrels can be swapped out using the Savage-style nut.

I am confident of this. If the day comes where the competitive shooters setting the 1000 yd world records all consistently using Savage-style barrel nuts, then it will have been handily demonstrated that the non-nutted action competitors are at a disadvantage. I'm talking the guys shooting off the bench, eeking out the best accuracy their rifles have to offer. Not the fellows shooting prone off the ground. If the action nut adds anything substantial to accuracy, I believe we will eventually see it become THE standard method of competition rifle assembly. No? Then we could have some reason to believe that action nut accuracy theory, and reality, are one in the same.

Good shooting, with or without the nut.

 

[Trickymissfit]

TM,
I'm looking to understand the concept behind your contention that the barrel nut will set the threads on the tenon to the threads within the action in a manner that will yield better accuracy from a rifle. Simple as that. If you are able to explain it, I'm open to your discussion - no matter what color you place on the kettle.

A point of clarification: I never specified a magnitude of any percentage of thread contact in any of my previous posts. You may be confusing my posts with those of another Forum member or members.

I'm not following the "small error in my post that needs to be rectified". You could be right, but I don't know what error you speak of so I can't really work with that and respond.

The use of the nut makes the nut an additional contact face in the assembly of the barreled action, and a key part in maintaining the concentricity within the barreled action assembly. I can understand that with the use of a nut, the threads are positioned within the barreled action first, and then placed under tensile force with the use of the nut without any further turning of the barrel threads into the action threads. The thread contact surfaces can remain stationary while the nut is tightened down. But tightening the nut down to generate the tension force on the barreled action places the nut thread to barrel thread contact in the same situation the barrel threads and action threads are placed under if the barrel is threaded into the action and tightened against the shoulder without the use of the nut. The threads are being turned (the contact surfaces are rotating) at the same time the tightening torque is being developed. So if that's a bad thing for the barrel thread to action thread fitment while torquing (tightening) of a non-nutted barreled action, it should likewise be a bad thing for the nut thread to barrel thread fitment when the Savage-style nut is torqued down.

Your contention that the use of the nut is a more controlled method of placing the barreled action thread assembly under tension seems to have merit. But your contention that the method will improve the accuracy of a rifle is up in the air. It seems to have neglected the inclusion of an additional set of threads (nut to extended barrel tenon threads) that have to be precisely cut and the additional mating surface of the face of the nut to the face of the action. I'm not a machinist, but I can envision that squaring up the face of a threaded nut in a lathe so that the action mating face is exactly perpendicular to the thru-bore of the threads in the nut is a headache - compared to squaring up the shoulder on a 20" plus long barrel that can be easily chucked up in the lathe. But I'm sure a good machinist would find a way.

I do appreciate your effort to explain yourself. Perhaps its just me. The jump from employing the barrel nut to improved accuracy is getting lost in the fog.

I can fully appreciate the ease with which barrels can be swapped out using the Savage-style nut.

I am confident of this. If the day comes where the competitive shooters setting the 1000 yd world records all consistently using Savage-style barrel nuts, then it will have been handily demonstrated that the non-action nutted competitors are at a disadvantage. I'm talking the guys shooting off the bench, eeking out the best accuracy their rifles have to offer. Not the fellows shooting prone off the ground. If the action nut adds anything substantial to accuracy, I believe we will eventually see it become THE standard method of competition rifle assembly. No? Then we could have some reason to believe that action nut accuracy theory, and reality, are one in the same.

Good shooting, with or without the nut.

look I'm not trying to start a fight! All the stuff I've posted is what I've learned thru about twenty years of fooling around, plus another twenty five on the job. There are things I like about both concepts and things I don't like. To a certain extent I think both systems are over rated. I was a shoulder person up and untill about the year 2000 even though I knew about the stretched thread concept long before that (never put the two together). But I was also unaware that a barrel acts like a coiled spring when a bullet passes thru it (in two directions 180 degrees apart) then I picked up on some stuff that Bill Calfee put in print, and used it. It worked! What I'm trying to say is gather in all the data you can find and put it to work for you. Most guys look at a barrel as ease of use (and we all will buy into that). But if done right the headspace will be just as good with a shoulder. What I found out was in what happens after all this becomes a set dimension (there is a catch here), and the nut can be your friend.
gary

 

[Pdvdh]

look I'm not trying to start a fight!
gary

I never claimed or stated that, because I never interpreted you to have any such intent.

I requested an explanation of your contention that barrel-nutted action assembly of the barreled action resulted in an improvement in rifle accuracy compared to non-barrel-nutted assembly of the barreled action.

Again, good shooting to you.

 

[Coyboy]

Well let me throw in somthing to think about! Not that this post hasen't made us think of plenty already.

I have been workin on a nutted remington reciever. Not conventional in any sence of the savage nut.

The remmy action has no internal threads(bored out) but external threads 20 tpi. the barrel has no threads but will be machined for a tight slip fit into the reciever. Along with the bolt nose counterbore it will also need a counterbore to accept the lugs, as the barrel "tennon" will actually extend back to the reciever lug abutments. The barrel will have a shoulder that mates to the reciever face and a mating nut that is slid over the barrel and tightened to the reciever. This nut also acts as the recoil lug with a double shoulder.

This required adding a new scope base hole in the front reciever ring as the nut covers the front one up.

Kind of ar-15 style barrel fitting but no seperate thread extension.

Allows barrel indexing 360 degrees with the twist of a nut, and no headspace changes. Multiple barrels can be fit to the reciever and swapped out quickly. The 3 "rings of steel" just turned into 4.

Nate has seen this one off creation when he timed and tigged a new handle on, When customers work gets caught up I will get this thing barreled up for a short range f-class rig in 6br for next season.

This will likly only be a one of it's kind as it was somthing to satisfy my curiosity and help me sleep better at night!

 

[Pdvdh]

Interesting. All the threads do is keep the barrel shoulder tight to the receiver face.

If that 'machined... tight slip fit' of the mating surfaces of the barrel tenon into the receiver is snug enough, long enough, and strong enough (supported with enough steel in the thickness of the surrounding receiver), I suspect it will be a shooter.

Having the bolt lugs lock into the barrel rather than the receiver could be beneficial to accuracy. Again provided there's enough mass of steel where the bolt lugs engage the barrel to endure the stress of repeated fire and use.

One question. Is the hardness of the steel used in barrels equal to the hardness of the steel used in the manufacture of bolts and receivers? I don't know the answer to that, but one of you gunsmiths will. If barrel steel is softer than receiver steel, then the bolt lugs might set back the barrel steel under recoil - where the bolt lugs make contact with the barrel.

You ought to post some pics!

 

[James H]

Well let me throw in somthing to think about! Not that this post hasen't made us think of plenty already.

I have been workin on a nutted remington reciever. Not conventional in any sence of the savage nut.

The remmy action has no internal threads(bored out) but external threads 20 tpi. the barrel has no threads but will be machined for a tight slip fit into the reciever. Along with the bolt nose counterbore it will also need a counterbore to accept the lugs, as the barrel "tennon" will actually extend back to the reciever lug abutments. The barrel will have a shoulder that mates to the reciever face and a mating nut that is slid over the barrel and tightened to the reciever. This nut also acts as the recoil lug with a double shoulder.

This required adding a new scope base hole in the front reciever ring as the nut covers the front one up.

Kind of ar-15 style barrel fitting but no seperate thread extension.

Allows barrel indexing 360 degrees with the twist of a nut, and no headspace changes. Multiple barrels can be fit to the reciever and swapped out quickly. The 3 "rings of steel" just turned into 4.

Nate has seen this one off creation when he timed and tigged a new handle on, When customers work gets caught up I will get this thing barreled up for a short range f-class rig in 6br for next season.

This will likly only be a one of it's kind as it was somthing to satisfy my curiosity and help me sleep better at night!

Jim,
Sure would like to see some pictures, it sounds interesting. Do you really think it's going to help you sleep at night or just give you more things to think about?

 

[Coyboy]

Interesting. All the threads do is keep the barrel shoulder tight to the receiver face.

If that 'machined... tight slip fit' of the mating surfaces of the barrel tenon into the receiver is snug enough, long enough, and strong enough (supported with enough steel in the thickness of the surrounding receiver), I suspect it will be a shooter.

Having the bolt lugs lock into the barrel rather than the receiver could be beneficial to accuracy. Again provided there's enough mass of steel where the bolt lugs engage the barrel to endure the stress of repeated fire and use.

One question. Is the hardness of the steel used in barrels equal to the hardness of the steel used in the manufacture of bolts and receivers? I don't know the answer to that, but one of you gunsmiths will. If barrel steel is softer than receiver steel, then the bolt lugs might set back the barrel steel under recoil - where the bolt lugs make contact with the barrel.

You ought to post some pics!

The lug abutments of the reciever are still in use the actual barrel steel will be capable of bumping up against them, weater I bump the lugs or not is another experiment in itself. I have thought about that extensivly and will likly leave a .002 clearance from abutments to barrel.

 

[Coyboy]

Jim,
Sure would like to see some pictures, it sounds interesting. Do you really think it's going to help you sleep at night or just give you more things to think about?

James, I am not sure? I was thinking about this for a few months and one night it kept me up. The next day I pulled a new sps off the shelf and bored the threads out of it, made a nut and threaded the OD. The barrel I am using is CM and I had Brux contour it to save a bit on my machine time with the shoulder and such. It showed up a couple weeks ago. If I wasn't in the fall "rush" I would barrel it tommorow.

 

[James H]

Jim,
Sorry I thought you had the project finished, now you're going to keep me awake at night.
I see no reason this won't work and am wondering why it hasn't been tried before. Maybe it has and just havn't heard of it.
Did you happen to cut an angle to the barrel seat in the receiver. It seems to me that would ensure that the tenon had no oppertunity to move at all since there needs to be some kind of clearence to fit the barrel into the receiver unless it is a press fit. It sure is a simple way to play with effects of barrel indexing.lightbulb
Good luck with the project and please keep us posted.

James

 

[specweldtom]

phorwath, Remington and Weatherby MK V bolts are harder than the barrels. I haven't tested the receivers, but my impression is that they are in between the bolts and barrels in hardness. Good question, particularly in the case of bolt lock-up in the barrel instead of the receiver.

Jim, the separate barrel extensions on the AR's also seem to be harder than the barrels. Question: does one of the recent Remington factory rifles have the lock-up in the breech of the barrel? I haven't seen one, so I don't know if or how they did it, but I do know that the AR system works very well, so why not?

Tom

 

[Coyboy]

phorwath, Remington and Weatherby MK V bolts are harder than the barrels. I haven't tested the receivers, but my impression is that they are in between the bolts and barrels in hardness. Good question, particularly in the case of bolt lock-up in the barrel instead of the receiver.

Jim, the separate barrel extensions on the AR's also seem to be harder than the barrels. Question: does one of the recent Remington factory rifles have the lock-up in the breech of the barrel? I haven't seen one, so I don't know if or how they did it, but I do know that the AR system works very well, so why not?

Tom

Not sure how the new remington modular system works. Machining lug abutments into the barrel breach was never in the cards for this particular test. I seen it more as a way to prevent threading the barrel all together.

 

[Will83]

Whatever you decide, just always cover your barrel!