Contour - Hunting Rifle - Threaded Barrel

[uncle fester]

I am In the process of building a hunting rifle in 7mm Rem Mag on a Bighorn Origin Action. With a long action and barrel, it certainly won't be a lightweight mountain rifle. Nevertheless, I do intent to carry it and want to keep it reasonably lite.

Question: What is the lightest barrel contour that can reasonably used with a threaded barrel?

 

[Will Henry]

Are you speaking of threading the barrel for a compensator or a brake? If so, in 7mm, .550 at the muzzle is as small as I would go. WH

 

[Judd]

Hard to answer without knowing how long you’re wanting the barrel and which thread. Example, 24” and 5/8-24…I recommend a Bart 3b or Brux #5...but if you drop down to 20” then a #4 and 16” a #3

Good luck.

 

[CJ6]

The smallest muzzle dia. I have a brake on is .720

 

[uncle fester]

Are you speaking of threading the barrel for a compensator or a brake? If so, in 7mm, .550 at the muzzle is as small as I would go. WH

90% of the time for a brake. Occasionally, I might want to add my Dea Air Nomad can.

I want a finished length of 24".

 

[tobnpr]

It's indirectly related to contour- it has everything to do with a minimum diameter at the muzzle, where the tenon will be threaded.

General rule of thumb is minimum .100 barrel wall thickness.
.284 + .200= .484.
This would be a typical 1/2"-28 tpi tenon. Particularly with a magnum, more is better to avoid bell-mouth at the muzzle.

Commercial brakes typically seat on a shoulder- again, .100 minimum shoulder- which brings you to a minimum muzzle diameter of approx. .700. As long as the barrel is minimum .700 at the muzzle it will support the 1/2"-28 tpi brake. With a custom brake designed to bear on the muzzle and not barrel shoulder, you don't need to be any larger than the 1/2" tenon.

.750 at the muzzle, and a 9/16" brake would be my recommendation for this. If I need to "push" it, I prefer to keep barrel wall thickness as much as possible and skimp on the torque shoulder. Brakes can seat on a lesser shoulder/less torque with Rocksett to secure them.

ETA:
Just noticed you mentioned a can- then forget about a lesser shoulder. I wouldn't do a can on anything less than a .100 shoulder- check the tenon specs for your suppressor to be sure.

JMO, YMMV.

 

[WSnyder]

I haven't kept up with it or kept track of who is doing it but I've seen mentions of light contours turned with custom larger flared muzzles for suppressor use. Might want to search the various forums and see which barrel manufacturers might do this type of contour.

For reference this is a pretty good discussion on this topic:

Optimum Lightweight Barrel for Suppressor

I'm looking for some input on ultralight rifles with suppressors. Since this is a LR forum, lets begin the discussion by saying we are using a magnum cartridge for LR hunting on elk sized game to 1000 yards. I'd like the weight to be

www.longrangehunting.com

 

[Will Henry]

Again, mounting of a can is a whole different matter and I wouldn't want to be any less than .700 for this. For a brake, a diameter of .550 is workable for a brake with a 1/2 x32thread, this for 30 caliber and under. WH

 

[uncle fester]

Thank you everyone, You convinced me to get the barrel sans threading and brake.

 

[X Count]

Run some numbers on length vs fps and weight. I did recently and ended up with a 20" heavy Palma. Balances really well and only lost about 100fps which is virtually nothing out to about 350. Out to 1000 it was about .5moa more drift and 3moa more drop.

 

[Edd]