Does this gunsmith know something that the rest of us do not?

They react

Basically they shoot the same for the first 5 or 6 rounds. On those that I used addittional torque, they maintained the same level of accuracy for a much longer time. For testing, I don't see a real problem, but as one mentioned, if we could chamber the barrel after it's fitted to the action, I feel the accuracy would be better, as long as you get it right. Sure would like to try that sometime. As far as I can tell, you've come a long ways in the last month.
 
Fred J said:
Basically they shoot the same for the first 5 or 6 rounds. On those that I used addittional torque, they maintained the same level of accuracy for a much longer time. For testing, I don't see a real problem, but as one mentioned, if we could chamber the barrel after it's fitted to the action, I feel the accuracy would be better, as long as you get it right. Sure would like to try that sometime. As far as I can tell, you've come a long ways in the last month.
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You guys have answered a lot of questions, -THANKS-... i been "burning up" the site :D !! Several years back i didn't like computers (old school thinking i guess). A computer is the best learning tool in the wolrd -i would hate to live without one now.

You guys have a very nice -advanced gun school going on here and it's free. I know you don't want to hear it but Mr. Obama would be proud of you guys, even Big Al, lol. Not everyone has enough sense to do the right thing like you guys are doing!

... and i'm kinda proud of what Mr. Jerry and several others have been teaching me about lathe work! I got a few more dumb questions coming to, lol -thanks joe :)
 
jGEE said:
Mr. Charles respectfully i think your comment is a little unfair, you make it sound like i don't trust you guys -i wouldn't be here if i didn't, you guys are very helpful and save my butt a lot, thanks! In the few months i have been here i have already learned years of knowledge.

joe :)
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Joe, I garauntee that Charles meant no disrespect.

His reference to automotive torque standards was brought up because it is one of the most common and widely experienced reference standards that we have documenting torque values used in metal applications similar to rifle barrel/action stuff.

Threaded rifle barrels, to my knowledge, do not have a similar torque standard certified data base to draw from, unless barried in some military archive from one of the small arms military testing facilities.

Also, the reference to auotomotive standards may also have been made since so many other past messageboard discussions, over the years, have contained detailed torque discriptions relating to auto standards...........................Don
 
Barrel Torque Value

I was taught to torque centerfire rifle barrels to 100 Ft-Lbs. using anti-seize compound and that is the way that they leave our shop. If you look in the Machinery’s Handbook for typical barrel threads and torque values; 100 Ft-Lbs. isn’t even close to what those threads would be tightened to if you were holding parts together. I’m sure that the cross section of a receiver is capable of handing much more torque than 100 Ft-Lbs but have I never seen the need to go any higher as I’ve never had a barrel come loose from 100 Ft-Lbs. of torque.

Repeatability is key,
Nic.
 
Niccolo said:
I was taught to torque centerfire rifle barrels to 100 Ft-Lbs. using anti-seize compound and that is the way that they leave our shop. If you look in the Machinery’s Handbook for typical barrel threads and torque values; 100 Ft-Lbs. isn’t even close to what those threads would be tightened to if you were holding parts together. I’m sure that the cross section of a receiver is capable of handing much more torque than 100 Ft-Lbs but have I never seen the need to go any higher as I’ve never had a barrel come loose from 100 Ft-Lbs. of torque.

Repeatability is key,
Nic.
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I agree, 100 ft. lbs. is nothing when we are talking a well lubed 1.062 -16 thread.
 
Yes – I winced when I read this pulp fiction. One of these days somebody will get injured or killed with this hand tight barrel nonsense.

When I’m on the firing line, I sure hope my neighbor has his barrel tighter than hand tight and his action port is not pointed toward me.

In our shop, many rifles have been fixed over a thirty year period by simply tightening the barrel. This method fixes a lot of bad barrels and scopes too...

One late benchrest gunsmith used to fix another benchrest gunsmiths' inaccurate rifles by tightening the barrel. I was told he charged twenty bucks for the job, and kept it a secret for many years

Put ‘em on like a lug nut on your wheel. TIGHT.

One of these days I’d like to come up with an accurate figure. I’m going to get some strain gauges or fiber-bragg grating sensors and mount them from the receiver face to the barrel and acquire the data with LabVIEW and maybe put this topic to rest once and for all.

Greg Walley
Kelbly's Inc.
 
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Greg Walley said:
Yes – I winced when I read this pulp fiction. One of these days somebody will get injured or killed with this hand tight barrel nonsense.

When I’m on the firing line, I sure hope my neighbor has his barrel tighter than hand tight and his action port is not pointed toward me.

In our shop, many rifles have been fixed over a thirty year period by simply tightening the barrel. This method fixes a lot of bad barrels and scopes too...

One late benchrest gunsmith used to fix another benchrest gunsmiths' inaccurate rifles by tightening the barrel. I was told he charged twenty bucks for the job, and kept it a secret for many years

Put ‘em on like a lug nut on your wheel. TIGHT.

One of these days I’d like to come up with an accurate figure. I’m going to get some strain gauges or fiber-bragg grating sensors and mount them from the receiver face to the barrel and acquire the data with LabVIEW and maybe put this topic to rest once and for all.

Greg Walley
Kelbly's Inc.
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Hey Greg,

While you're at it find out at which point "the headspace changes"... :D

BTW, do you still have those Electron Microscope pix of crown damage etc from bronze brushes?

I've got paper copies but if you ever find time to post them again I'd like to print them out on photo paper for my reloading room wall.......

Thanks for taking the time

al
 
BTW, do you still have those Electron Microscope pix of crown damage etc from bronze brushes?
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Wow that's getting down to particulars!! Everything is down to .0001 in "Smithing".... except bbl tightening. I'm suprised you guys don't have a lock or hold close on the bolt if your gonna get into the what ifs!!:D Why no facts for bbl tightening, just stories????? I never realized how many people have been killed by loose bbls, maybe they need to be tigged? joe :D:D:D:D
 
jGEE said:
Wow that's getting down to particulars!! Everything is down to .0001 in "Smithing".... except bbl tightening. I'm suprised you guys don't have a lock or hold close on the bolt if your gonna get into the what ifs!!:D Why no facts for bbl tightening, just stories????? I never realized how many people have been killed by loose bbls, maybe they need to be tigged? joe :D:D:D:D
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plenty of facts available, plenty of testing..... the real Benchrest Gunsmith's all tighten their barrels.

I don't know of any safety issues though with hand tightening....

al
 
Al

The safety issue would be if the shooter was merrilly shooting along, and his barrel turned a tad, creating a headspace problem. (By headspace, I mean too much clearance between the face of the bolt and a resized case). Get enough, and a head separation could occur.

Back in the mid '90s, at an American Shooting Center Match in Houston, a well known shooter could not get anything to work. It was a Panda. Another shooter had some spare Panda Barrels, and offered him one. When they went to remove the bad barrel, it took hardly any pressure on the wrench to loosen it.

So, he just tightened that puppy correctly, and that barrel suddenly started shooting just fine.

Incidentally, that shooter occasionally post on this Forum........jackie
 
jackie schmidt said:
The safety issue would be if the shooter was merrilly shooting along, and his barrel turned a tad, creating a headspace problem. (By headspace, I mean too much clearance between the face of the bolt and a resized case). Get enough, and a head separation could occur.

Back in the mid '90s, at an American Shooting Center Match in Houston, a well known shooter could not get anything to work. It was a Panda. Another shooter had some spare Panda Barrels, and offered him one. When they went to remove the bad barrel, it took hardly any pressure on the wrench to loosen it.

So, he just tightened that puppy correctly, and that barrel suddenly started shooting just fine.

Incidentally, that shooter occasionally post on this Forum........jackie
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I absolutely agree with it shooting better tight.


al
 
My original question was
How much in accuracy am i givin up by "hand tight"?
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I think i can conclude by the post so far in this thread, accuracy does not improve past hand tight.
thanks everyone! joe:)
 
jGEE said:
My original question was


I think i can conclude by the post so far in this thread, accuracy does not improve past hand tight.
thanks everyone! joe:)
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Welll,

While you may CONCLUDE that, that's not what anyone is saying! I will say flat out that accuracy DOES improve from tightening to beyond 100ftlbs. I would not dream of shooting for anything meaningful with a hand tightened barrel..... I have done it for varmints and will again.

al
 
jGEE said:
My original question was


I think i can conclude by the post so far in this thread, accuracy does not improve past hand tight.
thanks everyone! joe:)
Click to expand...

If that is your conclusion, your perception is incorrect. It is the exact opposite.
 
Greg Walley said:
Put ‘em on like a lug nut on your wheel. TIGHT.

One of these days I’d like to come up with an accurate figure. I’m going to get some strain gauges or fiber-bragg grating sensors and mount them from the receiver face to the barrel and acquire the data with LabVIEW and maybe put this topic to rest once and for all.

Greg Walley
Kelbly's Inc.
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Those of you who do not know Greg or have not visited his engineering lab in the Kelbly shop need to visit sometime. For example he has electronic mechanisms set up to measure trigger lock time, etc. Greg does more than a "I think" look at accuracy issues.

This entire Kelbly "compound" is dedicated to developing and making the best.
 
I watched a guy at the Super Shoot a few years ago pulling his hair out trying to get his gun to shoot. He had changed scopes about 3 times and finally figured out the barrel wasn't tight. That gun started shooting after he tightened the barrel up.

Everyone on this board knows this guy, as I won't mention his name, but he has several HOF points.

All I will say about the loose barrel not shooting problem is, been there done that!!

Joe Hynes
 
i don't think anyone will argue that a loose bbl is accurate, it's not. It is pretty much a given if the bbl loosens no telling where the shot will go.

Once you take the slack out of the threads and lock the action shoulder to the bbl. Is there an accuracy advantage to keep on with the torque settings.

I'm into rimfire, not a lot of twisting going on with subsonic ammo. Is it possible to get into "numbers"?

Al's experience tells him more torque adds to accuracy even past 100 ft pounds. Out of 33 post Mr. Al was the first to directly say YES INCREASED TORQUE ADDS TO ACCURACY.

Maybe others were implying the same thing but did not put it direct words. I was getting the feeling more tightening was to insure the bbl never came loose. I was getting the feeling nobody wanted to "commit" more torque increased accuracy like Mr. Al did. I don't know that's why i asked.

I don't want to build my Gun knowledge base by assuming what others might be saying. Mr. Al put it in black and white, in a direct way, thanks! Now i got another accuracy avenue to "ponder" on.

I guess a test could be done, probably has already been done but no-one has offered up specific data. There is data for about everything else.

Maybe a benchrest shooter could try -hand tight, 25' -50' 100' foot pounds and check group size at each setting and see what happens.

It would be nice to see a pic of the tool how torque is measured when tightening a bbl. I know what a torque wrench is -so there has to be some kind of adapter.

I can understand the theory just tighten the snot out of the bbl and go on, that should work every time. I was interested in the bare minimum torque valve and accuracy would not suffer. Nobody seems to wan to go there but maybe 1 person.

I don't want you guys to get mad or upset with me, i'm havin a lot of fun with this rimfire quest. thanks joe:)
 
Here is a picture of Dennis Sorensen's rear entry action wrench.

wrench.jpg


You just put your torque wrench on here and there you have it.


Sorry about borrowing your wrench Dennis.:)


James
 
Joe, there are not degrees of tightness that can be related to degrees of accuracy. There are the extremes we have discussed.

There is loose and loose will not work.

There is tight and tight will work.

Will a barrel tightened to 25 ft/lb shoot better or worse than a barrel tightened to 125 ft/lb? It might or might not depending on factors like, squareness of the tenon shoulder and thread profile and fit. A slightly off square shoulder or threads that are out of the 60-degree profile by 2-3 degrees might require more torque to load the tenon joint than a barrel that has a perfectly square shoulder and exact 60-degree profile thread.

You are asking questions like, on a race car, will it run faster if the wheels are torqued to 50 ft/lb than if the wheels are torques to 90 ft/lb. One thing for darn sure that race car will not run faster if the wheels come off!!!!
 
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