MartinDWhite
Member
- Joined
- Jun 10, 2015
- Messages
- 3
Search and search and I can only find a very few references to tensioned barrels on rifles. Most of the posts I read are armchair gunsmiths na saying the idea for various non-technical, or unsubstantiated reasons. Or someone saying they are going to do it, without any followup. Does anyone have a source of objective information for a tensioned barrel setup? The only few posts I find with completed setups say they increase accuracy and are lighter than a comparable sized thick/bull barrel. For me (as a machinist) it is way cheaper than a new barrel.
There is a patent http://www.google.com/patents/US4211146 that could be the reason it is not commercially available.
It could also not be commercially available because it costs. more because it still requires a conventional barrel manufacture to make a barrel to be modified.
I have a Remington 700 in .308 with a light/thin barrel. I can turn down the barrel at the receiver to press fit a piece of 1.25 x 0.83 steel tubing on to it. Then at the muzzle end I thread the last .600 inches 5/8x24 (for a suppressor), then thread the .750 inches before that to some larger thread with higher TPI, like 11/16x32. Then make a nut to go over the 11/16x32 to tension the barrel against the tubing. Since the barrel and tubing are both steel they should expand at the same rate if heat is effectively transferred to the sleeve.
If aluminum was used for the outer sleeve, which a lot of the na sayers ridiculed, the difference in expansion length for a 18 inch barrel between 70*f and 200*f is only 0.03 % between a steel barrel and aluminum outer sleeve. I can't find any numbers on overall barrel stretch in tension setups, so the difference in expansion is difficult to quantify for effect on tension. If the receiver end and mating sleeve end were threaded (1.125x32, same TPI as tensioning nut), it would be easy to test the difference by just swapping out the outer tube.
In steel is should add less than 26 oz to the rifle on an 18 inch barrel. In aluminum is should add less than 11 oz. Putting the suppressor on is an additional 16 oz. Not a super light rifle, but lighter than a big thick barrel.
Any real world feed back would be appreciated.
There is a patent http://www.google.com/patents/US4211146 that could be the reason it is not commercially available.
It could also not be commercially available because it costs. more because it still requires a conventional barrel manufacture to make a barrel to be modified.
I have a Remington 700 in .308 with a light/thin barrel. I can turn down the barrel at the receiver to press fit a piece of 1.25 x 0.83 steel tubing on to it. Then at the muzzle end I thread the last .600 inches 5/8x24 (for a suppressor), then thread the .750 inches before that to some larger thread with higher TPI, like 11/16x32. Then make a nut to go over the 11/16x32 to tension the barrel against the tubing. Since the barrel and tubing are both steel they should expand at the same rate if heat is effectively transferred to the sleeve.
If aluminum was used for the outer sleeve, which a lot of the na sayers ridiculed, the difference in expansion length for a 18 inch barrel between 70*f and 200*f is only 0.03 % between a steel barrel and aluminum outer sleeve. I can't find any numbers on overall barrel stretch in tension setups, so the difference in expansion is difficult to quantify for effect on tension. If the receiver end and mating sleeve end were threaded (1.125x32, same TPI as tensioning nut), it would be easy to test the difference by just swapping out the outer tube.
In steel is should add less than 26 oz to the rifle on an 18 inch barrel. In aluminum is should add less than 11 oz. Putting the suppressor on is an additional 16 oz. Not a super light rifle, but lighter than a big thick barrel.
Any real world feed back would be appreciated.
