?To nut or not to nut?

[J E Custom]

I'm getting ready to build two 338's on Savage long actions, I was thinking that with the longer 30in+ heavy barrels that shouldering the barrel conventionally and not using a nut would support the barrel better but I know some of you guys are rocking monster tubes with the nut, I need some pro and cons here.
Barrel swapping is not a prime concern, consistency and accuracy are!!!

Obviously this will never get resolved because there is nothing wrong with ether type
of thread connection of the barrel to the action "SO" to help answer your original question
let me explain why I "Prefer to use the shoulder method"

Thread barring surface has not been agreed upon so we will fore go that and simply look at
the total bearing surface error= with a shoulder type joint you have ''2'' parts to assemble
and any slack/thread fit is plus 2.

With the Nut there is a third piece with the same error if the threads are cut the same.
"SO" now you have added 33.3% error to the make up.

So by eliminating the nut you have improved the chances of a better fit/ True by1/3.

Next as to the cantilever effect think about a 1.250 shank supported by a 1.250 shoulder
as compared to a 1.062 shank supported by a nut that only adds .078 to the shank because
the cross section between the root of the threads and the groves in the nut for removal
measures .076 on the one I am using to get this thickness readings. so when added to the
shank of the 1.062 shank the effective shank diameter is 1.138 and only for 1/2" .

This means that when I do a shoulder type connection i have a shank diameter of 1.250
(Standard blank diameter) that is 2.500 long from the shoulder as opposed to 1.138 for
one half inch with the nut type connection. PS; The front of the nut that is tapered down
for looks does not touch the barrel and offers no support.

So you be the judge. "TO NUT OR NOT TO NUT" That was the question.

This is the reason I elect to use the shoulder and loose the nut.

J E CUSTOM

 

[Pdvdh]

So you be the judge. "TO NUT OR NOT TO NUT" That was the question.

This is the reason I elect to use the shoulder and lose the nut.

J E CUSTOM

+1

I've read all the posts and I would do the same. Use the 'nut' for a bullseye on the target. About all it's good for.

 

[Coyboy]

skip the nut,

and when you build a pee shooter on the target action skip the recoil lug as well.

Mill a flat on the bottom of the action via Bat style.

My 6mmbr with a 1.250" straight shank likes it that way.

 

[Trickymissfit]

skip the nut,

and when you build a pee shooter on the target action skip the recoil lug as well.

Mill a flat on the bottom of the action via Bat style.

My 6mmbr with a 1.250" straight shank likes it that way.

I've long felt the whole concept of using a recoil lug was dated technology, but I did see a couple of interesting things when ran thru a mechanical CAD program that will show stress and flex in micro seconds. The whole action simply flexes all over the place in a twisted fashion that is revelant to the twist in the barrel as well as entry. The faster the twist rate the more induced reaction behind the bolt lugs, and this sorta proves itself out with the 1:17 twist 30 caliber barrels. It showed me that round actions are a major fault factor, and that an octagon shape was far better. But the real solution was an octagon shaped action using a three lugged bolt was the right direction. Then you nitride the outside of the action for a minimum of .040" case using two lugs and three bedding screws pulling the action flat against a steel bedding block. A round entering the barrel with a fast twist will actually push the barrel shoulder off the reciever face, and then spring back (all styles do this)

Still your thoughts are with a custom action, and thread was with factory actions. We should be more worried about the harmonics of the barrel and action than worrying about a shoulder or a nut seating on the shoulder. The harmonics created by the shock wave might want to make a lot of folks put the beloved actions up on the shelf forever. The 22 rim fire guys prove this every weekend, and the groups that Calfee and the boys shoot just leave me dumbfounded everytime I see a target.
gary

 

[Trickymissfit]

Obviously this will never get resolved because there is nothing wrong with ether type
of thread connection of the barrel to the action "SO" to help answer your original question
let me explain why I "Prefer to use the shoulder method"

Thread barring surface has not been agreed upon so we will fore go that and simply look at
the total bearing surface error= with a shoulder type joint you have ''2'' parts to assemble
and any slack/thread fit is plus 2.

With the Nut there is a third piece with the same error if the threads are cut the same.
"SO" now you have added 33.3% error to the make up.

So by eliminating the nut you have improved the chances of a better fit/ True by1/3.

Next as to the cantilever effect think about a 1.250 shank supported by a 1.250 shoulder
as compared to a 1.000 shank supported by a nut that only adds .078 to the shank because
the cross section between the root of the threads and the groves in the nut for removal
measures .076 on the one I am using to get this thickness readings. so when added to the
shank of the 1.062 shank the effective shank diameter is 1.138 and only for 1/2" .

This means that when I do a shoulder type connection i have a shank diameter of 1.250
(Standard blank diameter) that is 2.500 long from the shoulder as opposed to 1.138 for
one half inch with the nut type connection. PS; The front of the nut that is tapered down
for looks does not touch the barrel and offers no support.

So you be the judge. "TO NUT OR NOT TO NUT" That was the question.

This is the reason I elect to use the shoulder and loose the nut.

J E CUSTOM

first of all it's a 1.050-20 thread; not a 1.00-20 thread if it matters much. Now here's a test; take a piece of 4150 steel or 4350 steel that is pretreated. Turn the threads on the shaft, and make a nut with the same amount of threads the nut would have. Find a 100 ton arbor press and press them apart. Now take a piece of steel just like the other and turn a nut with .75" of thread and try to press the shaft out of the nut. Guess what? You'll run for your life before it lets go, and the 16 pitch will let go first everytime if your brave enough. The thread in the reciever takes the pressure, not the nut everytime. The only thing the nut does is to act as a jam nut. Draw the thread form up in CAD, and make a measurment accross the pitch diameter, and multiply that times how many threads are in the reciever on both threads. A fine thread is always stronger (you can find that out in that thread standards book). Now you find out what the shear strength is for the type of steel your using and do a little math (you might be just a little scared when you look at 416 stainless steel by the way). But to compound this, if the thread form flexes inside the female thread it is weaker. Once again it's the nature of the beast. There are a couple ways to beat this problem in either setup, but it done wrong they'll be a complete disaster. Yet the best setup is no threads period, and that's easy to do.

The cantaliver effect has been an argument for about 100 years now, yet nobody has ever proved out out without the slightest doubt. Heres why; 3/4" of threads is not enough to support a 22" long medium weight barrel; let along a cylinder (1.25" strait tube). The shoulder becomes a fulcrum actually aiding induced flex by leverage. This has been proven out more than once by the simple addition of a shoulder pilot in the reciever. The problem here is that most all actions have too short a bridge to make this work well (needs to be at least 1.00" long). This is one of the reasons the older 40X Remington works so well when compaired to the 700.
gary

 

[Pdvdh]

The conclusion? Throw the Savage nut in the landfill. It's nothing but solid waste.

 

[bigngreen]

To nut, or not to nut: that is the question: Whether tis nobler to shoulder and suffer the slings and arrows of Savage fans, or take arms against seas of Remingtons And by nutting end them? To nut: to shoulder; No more;and by shouldering we say end.

 

[Pdvdh]

To nut: to shoulder; No more;and by shouldering we say end.

And they all said... AMEN!

 

[Trickymissfit]

To nut, or not to nut: that is the question: Whether tis nobler to shoulder and suffer the slings and arrows of Savage fans, or take arms against seas of Remingtons And by nutting end them? To nut: to shoulder; No more;and by shouldering we say end.

yes but the ugly gun will out shoot pretty boy seven days a week and twice on Sunday.
glt

 

[J E Custom]

yes but the ugly gun will out shoot pretty boy seven days a week and twice on Sunday.
glt

Whoa !!!!!!

I'll Bet that brings on some comments.

J E CUSTOM

 

[Coyboy]

The conclusion? Throw the Savage nut in the landfill. It's nothing but solid waste.

This is a great thread.

I guess I should have kept the nut out of the trash on Chris's build.
It would have shot so much better than this;


http://www.centershotrifles.com/gallery/img/6mmBR_Savage_P1010003_target.jpg

oh but then again it's an 8 twist and not really a br gun.


http://www.centershotrifles.com/gallery/img/6mmBR_Savage_P1010003.jpg

 

[~Ace~]

Every Gunsmith I talk to wants my Nuts ! They hate Nuts because it takes work away from them.... Reality says... Savages with NUTS are Winning every major competition they enter. The hell with improperly applied physics, all that matters is how the **** thing Shoots. They Shoot Just as good With NUTS...

I heard the same Rhetoric about the floating bolt heads.... now folks are making Custom actions with Floating heads and NUTS.... Don't fix it if it ain't broke, and Never let Anyone take your NuTS !

 

[Pdvdh]

The most famous saying involving nuts... is NUMB-nuts.

 

[Trickymissfit]

Every Gunsmith I talk to wants my Nuts ! They hate Nuts because it takes work away from them.... Reality says... Savages with NUTS are Winning every major competition they enter. The hell with improperly applied physics, all that matters is how the **** thing Shoots. They Shoot Just as good With NUTS...

I heard the same Rhetoric about the floating bolt heads.... now folks are making Custom actions with Floating heads and NUTS.... Don't fix it if it ain't broke, and Never let Anyone take your NuTS !

I gonna confess here that up till that last five or six months I was a big proponet of the floating bolt system, but now I have a second thought or two. yet I can't prove out my ideas to be true or false. Just a nagging after thought. And for 99.5% of the shooters here the thoughts would be of no use. I'm a guy who jams bullets all the time in my six millimeter and smaller rifles, and I'm now thinking that the floating bolt head isn't as consistent as the fixed solid one. But with a .002" jump you'd never know what I'm thinking. Can't prove anything, so take it for what it's worth to you.

Let me tell you a little story that has nothing whatsoever to do with a gun. Way back in the early 1960's Ford showed up at Indy with a V8 engine. Placed second first time out, and the next year they did a complete redesign into a four cam motor. The rest is history. But the engine builders and chief mechanics made a push to get the motor banned because it was vastly different, and basicly they didn't understand the inner workings of it. Anybody see a parallel?
gary