  | 300RUM to 338 EDGE then back |
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02-12-2007, 04:44 PM
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Join Date: Jun 2004
Location: Fort Shaw, Montana
Posts: 6,162
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Re: 300RUM to 338 EDGE then back
Roy,
Torque values will vary from smith to smith. Some get very critical about this. I generally do not. I screw down a receiver until it bottoms out, work it back and forth several times to really work in the assembly thread lube and then give it a good torque and leave it.
I used to measure the barrel torque and have heard numbers anywhere from 80 ft/lbs to 40 ft/lbs is correct. TO he honest, the better the thread fit, the less torque you really need to keep them in place.
Things to consider however are, what velocity is your chambering likely to be getting, what bullet weight are you using, what twist are you using and such.
The lighter the bullets and slower the twist the less stress there is placed on the threads. If your driving a really heavy bullet in a fast twist barrel to high velocity, there will obviously be more stress on the thread torque level to keep that barrel in place.
All that said, I would say I probably torque my barrels to around 40 to 50 ft/lbs on average. Just a good pull on the receiver wrench.
Some BR shooters use much less then this and still have no problems with barrels turning out but comparing a 22 PPC with a 52 gr match bullet to a 338 AM with a 300 gr pill are totally different stories.
Critical thing is thread fit and even square, 100% contact on your barrel shoulder to the receiver or recoil lug. If you have that, you will need much less torque to keep a barrel in place.
The reason some Rem 700 barrels are so damn tight is because the thread fit is so bad that they fill the space between the threads with a thread locking agent and it can at times be a real pain to break loose. Especially with that damn taper right from the receiver like Remington does. Not a problem though, there are ways around that!! [img]/ubbthreads/images/graemlins/grin.gif[/img]
I have had two barrels that simply would not break loose no matter what I did, 15 minutes after the 5300 lb lathe got ahold of them the threads were clean and clear!!! [img]/ubbthreads/images/graemlins/grin.gif[/img]
Also, some firearm companies have a sad way of indexing flutes or bring headspace into adjustment. That is by torquing the living hell out of a barreled receiver. This is simply poor machining and the WRONG way to do it.
You may be suprised to find out that Ruger rifles for me at least are by far the most consistant barrels to easily brake free. Winchesters are by far the worst in my opinion, Rems are in the middle of the pack.
Kirby Allen(50)
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Kirby Allen(50)
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
Farther, Faster and Flatter then ever before.
Web Page: www.apsrifles.com
allenmagnum@gmail.com
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02-12-2007, 06:18 PM
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Join Date: Jun 2007
Location: North Idaho
Posts: 1,811
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Re: 300RUM to 338 EDGE then back
Dennis,
I built a mold box and used casting sand to make each half of the block using an old barrel to mold the barrel taper.
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02-12-2007, 06:51 PM
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Silver Member
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Join Date: Dec 2005
Posts: 181
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Re: 300RUM to 338 EDGE then back
I have had two barrels that simply would not break loose no matter what I did, 15 minutes after the 5300 lb lathe got ahold of them the threads were clean and clear!!! [img]/ubbthreads/images/graemlins/grin.gif[/img]
Kirby, you got me beat by a long shot with that equipment. Mine is just a Turnmaster 15"x50". She weighs in at 3300lbs. But anyhow, could I just machine a piece of aluminum maybe 5k overbore with a slot cut longways and chuck it and the barrel up in the three jaw. I would position the slot between the jaws and give it a squeeze. You think that would work. [img]/ubbthreads/images/graemlins/wink.gif[/img]
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02-13-2007, 10:31 AM
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SPONSOR
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Join Date: Jun 2004
Location: Fort Shaw, Montana
Posts: 6,162
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Re: 300RUM to 338 EDGE then back
Tim,
I never recommend using the lathe to remove any barrel. This is relatively common practice amoung many smiths but I look at my lathe as about second place only to my family as far as importance to me.
Once you get the barrel broke loose it would be better but I do not recommend putting that much force on your lathe gears. It is not designed for it and as such bad things can happen.
A barrel vice and receiver wrench are pretty cheap compared to preplacing the gears on a lathe!!!
Just my opinion. Yes it may be done but it may bite you in the rear down the road!!
Kirby Allen(50)
__________________
Kirby Allen(50)
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
Farther, Faster and Flatter then ever before.
Web Page: www.apsrifles.com
allenmagnum@gmail.com
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