I am just getting into precision reloading and couldn't find a meaning for "no-turn" chamber. Could someone give me a quick answer.
Thanks for your help.
Thanks for your help.
What is a "no-turn" chamber?
- Thread starter SSC
- Start date
Re: What is a "no-turn" chamber?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rb85cj7</div><div class="ubbcode-body">I am just getting into precision reloading and couldn't find a meaning for "no-turn" chamber. Could someone give me a quick answer.
Thanks for your help. </div></div>
It's a chamber with a larger throat, so one does not have to turn the necks of commercial cases to get them to fit.
I've read where tight match chambers like to have .001" of space between the neck wall and the throat wall of the chamber. With this tolerance, one generally will turn the necks down and remove the high spots.
Contrst this with a factory chamber, like my Savage, which blows out my necks to ~.344" and yields ample room around the brass.
Chris
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rb85cj7</div><div class="ubbcode-body">I am just getting into precision reloading and couldn't find a meaning for "no-turn" chamber. Could someone give me a quick answer.
Thanks for your help. </div></div>
It's a chamber with a larger throat, so one does not have to turn the necks of commercial cases to get them to fit.
I've read where tight match chambers like to have .001" of space between the neck wall and the throat wall of the chamber. With this tolerance, one generally will turn the necks down and remove the high spots.
Contrst this with a factory chamber, like my Savage, which blows out my necks to ~.344" and yields ample room around the brass.
Chris
Re: What is a "no-turn" chamber?
It's not throat clearance, it's chamber neck clearance. But other than that Chris is right. It's the radial clearance measurement of the chamber to the unfired brass at the neck.
It's not throat clearance, it's chamber neck clearance. But other than that Chris is right. It's the radial clearance measurement of the chamber to the unfired brass at the neck.
Re: What is a "no-turn" chamber?
The way this is set up, is thus.
You load a few "dummy" rounds and mike the necks. With good brass (Lapua) they should be almost exactly the same. Send them to your gunsmith and he will cut a chamber for about .001 or .002 over the largest case Dia. Then, in theory, you can just buy the chosen brand of brass and load it "tight necked" without the hassle of turning and also not work hardening the necks, which should lead to longer case life. Many of the guys doing these chambers will engrave on the barrel the actual neck dia. along with the cal.
I have had several done like this but it is more of a long range BR type thing rather than tactical. Also if you set up your dies correctly, you can load without resizing, or with very minimal sizing. I have had cases that I have done this with and loaded 50 times and then thrown them away with more life left. I think it would not be the best thing for a real rough and tumble tactical rig. One bit of dirt and pressure could skyrocket. I use mine in the field, but am very careful with my ammo, to keep it clean. I have had these chambers cut by Mike Lau and Greg Tannel at Gre-Tan.
Hope this helps
RTH
The way this is set up, is thus.
You load a few "dummy" rounds and mike the necks. With good brass (Lapua) they should be almost exactly the same. Send them to your gunsmith and he will cut a chamber for about .001 or .002 over the largest case Dia. Then, in theory, you can just buy the chosen brand of brass and load it "tight necked" without the hassle of turning and also not work hardening the necks, which should lead to longer case life. Many of the guys doing these chambers will engrave on the barrel the actual neck dia. along with the cal.
I have had several done like this but it is more of a long range BR type thing rather than tactical. Also if you set up your dies correctly, you can load without resizing, or with very minimal sizing. I have had cases that I have done this with and loaded 50 times and then thrown them away with more life left. I think it would not be the best thing for a real rough and tumble tactical rig. One bit of dirt and pressure could skyrocket. I use mine in the field, but am very careful with my ammo, to keep it clean. I have had these chambers cut by Mike Lau and Greg Tannel at Gre-Tan.
Hope this helps
RTH
Re: What is a "no-turn" chamber?
gets a good seal when the round is fired thus uping speed a little bit, easier on brass because its not expanding and contracting as much, most time the chambers are setup to shoot a certain bullet.
gets a good seal when the round is fired thus uping speed a little bit, easier on brass because its not expanding and contracting as much, most time the chambers are setup to shoot a certain bullet.
Re: What is a "no-turn" chamber?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rb85cj7</div><div class="ubbcode-body">What is the advantage of having the chamber so tight? </div></div>
Case life and accuracy.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rb85cj7</div><div class="ubbcode-body">What is the advantage of having the chamber so tight? </div></div>
Case life and accuracy.
