I need info.. help. Thread tightness survey, please post//

K

Kirk Ethridge

New member
How tight are your barrel threads compared with the descriptions below.? I need some data for future reference.

A. I can screw my barrel all the way to the action shoulder easily by hand.

B. I can screw my barrel all the way to the shoulder. but use an action wrench for the final tension.

C. My threads are tight, I must use an action wrench to screw the barrel up to the action shoulder.

D. The name of your Gunsmith? (as long as you don't think he would care)

Thanks Guys!!!!

Kirk Ethridge
 
Barrel Thread Compound

One important factor with barrel threads mating and torquing properly in an action, is lubrication. A good anti-seize/anti-galling compound distributes the thread contact and torque forces evenly. Full contact can be achieved with a 10-20% torque reduction. Also eliminates galling or seizing.

These compounds should contain at least 5% solids, and not just plain grease or oil.

Never had a barrel not lock up or break loose with anything more than a wrap of the palm on the action wrench.

My gunsmith, Billy Stevens, uses the same compound - Tru-Gard Barrrel Thread Compound.

...Dave
 
I strive for "B". I do all my BR rifles and send out my customs. I am talking woodstock and Mauser. I do my glass stocked hunting rifles.
Custom Gunmakers:
David Christman
Reto Buehler
Jim Kobe
James Anderson
These guys are ACGG members
Butch
 
The force needed will also depend on how good the shoulder of the barrel & face of the receiver are done, too. When it's all good, I can put a barrel on by hand (no wrench) with a final wrist snap , but need a wrench to take it off. But that's just the fit, I always use a wrench to tighten the barrel, esp. if the scope is mounted on the receiver.
 
I strive for "B"

For my SS Viper that has a 1.0625" x 18TPI Tennon, I cut it to 1.061" and thread for a depth of .046" to .048". I use the compound dial for this depth measurement and start checking the fit around .045" deep. I stop threading when the receiver will screw on by hand and the receiver face and barrel shoulder makes contact.

Remington 700's, I open the receiver to 1.072" and use a Tennon diameter of 1.070" x 16TPI. Thread Depth of .054" and I start checking the fit at .050"-.052" deep. I fit these the same as I do my Viper.

Gunsmith, self
 
Our Pandas have been done by Scott and Pierce. Our Panda barrels fit into the "B" description you have Kirk.

Paul
 
Kirk

Since I am a machinist, I can make the threads any way I want. I choose to make them where the barrel screws on all of the way and seats against the shoulder by hand.
Just before it seats, you can shake the muzzle end about 1/8 inch. In actuallity, the pitch diameter has about .001 clearance.
I do tighten barrels a little more than some. I have seen my share of Rifles that would not shoot suddenly come to life when the shooter finally got the barrel tight enough.
There are misconceptions about threads. The first requirement of a Benchrest Rifle's thread is it hold the barrel secure enough so it cannot move any what so ever under firing. In order for a thread to hold properly, it must be placed in tension. That means, you need to tighten the barrel to where the metal is actually stretched. If the metal is not put in tension, you will not have a secure joint. I figure I am stretching the barrel joint on my Rifles about .002 inch.

Many innovations have cropped up trying to tighten up the radial alignment of a barrel. I consider all of these solutions to problems that do not exist, as a properly fit 60 degree thread is self centering.

A good example of tensioning is a typical bolt such as found in a cylinder head of an engine. In todays modern large capacity engines, (big diesels), mechanics actually measure the stretch of the bolt to a predetermined length, so the load produced will secure the head properly. Similiar methods are used with connecting rod and main bearing bolts.
When I install a barrel on my Farleys, I seat it securly against the shoulder, place a mark between the barrel and the action, and tighten the action to where it advances that mark about 3/32 inch past the first. This takes about 130 or so ft pounds of torque. I use the marks because I want to be sure that the barrel did indeed advance on the thread.
Your "c" is an open invitation to disaster. You only have to gall a Stainless Barrel in an action once to see why........jackie
 
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"B"

"C" is absolutely a disaster............ no invitation needed, stainless to stainless I'll predict a locked up action to barrel 9 times out of 10 unless the threads are EXTREMELY smooth....... then I'd drop down to 7 out of 10 :D


al
 
Anybody using "C" will change his ways rather quickly. I use thread wires or a thread mic' and "B", torque to 90 pounds but Jackie has me considering going to a higher torque number. I use Dow "Molykote G" paste as a thread lube.
 
It's "B" for me.

TOO TIGHT= TOO BAD
Too Loose= OK
LITTLE LOOSE= JUST RIGHT

Jackie

I've been down that road twice. I did it once and when I had help here he did it once, never again. I use Jet Lube 550 on my threads and shoulders. As easy as they break loose I know I'm putting more torque on the barrel/threads than I ever did when I was using syn grease.

Dave
 
Language may be getting in the way here. I'm sort of an A and B guy. That is, when I get it what I think right, I can screw the barrel on easily by hand (That's A). But I use a wrench for the final torque (That's B).

Even "B" scares me, if you mean "a robust 30-year old male can get it on without a wrench and not grunt much."

Having said that, I think A+B is what Dave & Jackie & most everybody else is saying.
 
Dave, Charles

I just caught that. I suppose there are shooters who thing that just snapping the barrel against the shoulder is sufficient to hold it in place. I strongly disagree with that.
As I said before, a threaded joint must be placed in tension in order to function as it should.........jackie
 
Barrel Torque

Jackie,
You're absolutely correct in what you're saying about needing to be in tension. But it only needs to be just a little bit more than the stress put on the joint with a bullet firing such that you never unload the shoulder compression. I calculated and use 60 ft-lb's with a smooth turning threads with anti seize compound.

I think 70 ft-lbs would handle even your LOADS!!!!:D
 
wnroscoe said:
I strive for "B"



Remington 700's, I open the receiver to 1.072" and use a Tennon diameter of 1.070" x 16TPI. Thread Depth of .054" and I start checking the fit at .050"-.052" deep. I fit these the same as I do my Viper.

Gunsmith, self
Click to expand...

As I read it, this is a slip fit!
 
Kirk, I can't remember what action you shoot but if it is a Stolle Panda for example, get a brochure from Kelblys that shows the thread diameter "over wires". What it shows for their 1-1/16-18 tenon is that the finished thread should mike 1.0715 +/-0.002" over 0.032" diameter wires. You can get some 1/32" diameter straight shank drill bits from the local hardware or from Travers, MSCdirect, etc. You will need 3 wires so get 4-5 in case you lose one.

http://www.jjjtrain.com/vms/eng_mhandbook/eng_mhandbook_07.html

Notice that they recommend that diameter +/-0.002" (that is 0.004" total tolerance). That means there is some leeway on thread tightness, as long as it is not too tight.

Threading a barrel for a Panda to the exact dimension shown above will give you a good feel for the needed tightness of barrel threads.

On barrel tightening, use a good antiseize and about 150 ft/lb. Just snapping for tightness has given the scope lockers and Cecil Tucker a lot of business.
 
jerry and jackie,

i am assuming you use an action wrench and a bbl vice to tightten with.

what type of vice/jaws do you use to hold for a 100 plus lb torque ?

thanks

mike in co
 
Barrel tension

With Shoulder to action fit I use a "2B" fitting hand tight until shoulder contact. 65-90 pounds.

With actions using barrel nuts(Savage) hand fit them, then tighten the barrel nut 50 50-60 pounds.

I am with Dave and Jackie there is nothing worse than a galled barrel in an action.

I use a high temperature molly grease. Have never seen that the high dollar anti-seize did any better. I have never had a barrel that I greased up the threads and the points of contact ever seize up.

Rustystud
 
mike in co said:
jerry and jackie,

i am assuming you use an action wrench and a bbl vice to tightten with.

what type of vice/jaws do you use to hold for a 100 plus lb torque ?

thanks

mike in co
Click to expand...

(not Jerry or Jackie) I have a number of aluminum blocks bored to barrel diameter or taper and then cut into two pieces. A dusting of rosin (Brownells) on the contact surfaces and clamp the two blocks in a heavy machinists vise or in a barrel vise and tighten away. I'ver read that sugar works if you don't have any rosin. Some folks use hardwood instead of aluminum.

Jay, Idaho
 
Thanks for the info guys....

I had a rifle (k-15 american) 3 lug hunting rifle i sent to Arnold arms a number of years ago for installation of a 277 Arnold barrel. (It was originally a 257 Weatherby mag. The Arnold shot better and was a little faster, However i now find i'd rather own this type rifle where at least some factory loaded ammo might be found. I went to take off th Arnold barrel , finally got it off by placing sand paper strip between barrel and block. (it was too slick before a lot of pressure it still turned... finally got it off. the fit was so tight, i had to use the wrecnch to spin off the barrel with considerable pressure... I cleaned up the threads and went to put the 257 Weatherby back on...It was just as tight.. I had to use the wrench all the way to the shoulder! I was just waiting for it to "lock up" (moly paste) It finally came to a dead stop at the shoulder....

this is of course a chrome moly actiona nd barrels... Are they done this way as the norm!

Kirk
 
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