Gunsmithing Threading Barrel ?

Victor N TN

Retired civilian fart
Full Member
Minuteman
Feb 16, 2002
4,025
11
68
Knoxville TN
Re: Threading Barrel ?

It's better to discuss what is and isn't done with the 'smith that's doing the job. Different people do it different ways. But I always do it seperately.
 

eddieharren

Sergeant
Full Member
Minuteman
Aug 4, 2007
320
1
74
Ijamsville, Maryland
Re: Threading Barrel ?

I would advise re-crowning when threading for a can or brake if, the round count was over 500-600 rounds. While the g-smith has the barrel trued up, it would be a perfect time for a fresh crown. JMHO.
 

300sniper

Gunny Sergeant
Full Member
Minuteman
Jan 17, 2005
3,438
17
Greenwood, Ca
Re: Threading Barrel ?

it probably depends on who's doing it for you. i always touch up the crown when threading a muzzle since i already have spent the time to get the barrel running as close to true as possible in the lathe. touching up the crown only takes a couple minutes.
 

wnroscoe

Gunny Sergeant
Full Member
Minuteman
Jun 12, 2006
3,908
54
NW Louisiana
Re: Threading Barrel ?

It only makes good sense to touch up the crown once the muzzle has been indicated in, at least touch up the chamfer if nothing else.
 

BlackOps Tech

Still The Head Skunk
Commercial Supporter
Full Member
Minuteman
Re: Threading Barrel ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">It only makes good sense to touch up the crown once the muzzle has been indicated in, at least touch up the chamfer if nothing else. </div></div>

+1....
 

SmallBoreSnipers

Gunny Sergeant
Full Member
Minuteman
Aug 15, 2009
1,204
0
41
Troy, NY
Re: Threading Barrel ?

Ok. So it looks like taking care of the crown is the way to go. What if the O.D. of a brake is larger or smaller than a O.D. of a barrel? Have does it have a nice flush fit to the barrel?
 

wnroscoe

Gunny Sergeant
Full Member
Minuteman
Jun 12, 2006
3,908
54
NW Louisiana
Re: Threading Barrel ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SmallBoreSniper</div><div class="ubbcode-body"> What if the O.D. of a brake is larger or smaller than a O.D. of a barrel? <span style="text-decoration: underline"><span style="font-weight: bold">How does it have a nice flush fit to the barrel? </span></span></div></div>

This is addressed by having a competent gunsmith install it.
 

Victor N TN

Retired civilian fart
Full Member
Minuteman
Feb 16, 2002
4,025
11
68
Knoxville TN
Re: Threading Barrel ?

If the person doing your work is a competitant machinist and gunsmith, he / she can make a bushing / adapter to fit whatever is available.

Edited to add: For my own barrels I touch up the crown every time I have the barrel off.
 

shooter53

Private
Full Member
Minuteman
Oct 29, 2008
55
0
66
Florida
com
Re: Threading Barrel ?

I always clean up the crown when shortening a barrel for the client. As for a mismatch in brake vs. barrel diameter, I ask the client if they prefer a tapered mating or the stepped look.
We also determine what finish will be used on the brake..

All this is cleared up with the client before the barrel ever gets mounted in the lathe.

Hope this helps.
 

Texar2

Sergeant
Full Member
Minuteman
Aug 9, 2008
447
2
Texas
Re: Threading Barrel ?

I always recess the bore just a touch deeper than the length of the threads. If your threads are .5 inch long i would recess the bore about .510. Once you thread a barrel the barrel wall can be very thin. Never made sense to me to have a bull barrel taper to a small diameter under the brake. When that wall heats up it can walk (especially with the constant exterior force from the threads pulling at each other). For a .308 i use a .325 reamer. You might lose .5 inch of bore but at least you know your muzzle is good.
 

LongRifles Inc.

Lance Criminal
Full Member
Minuteman
  • Mar 14, 2010
    5,860
    4,579
    50
    Sturgis, S. Dakota
    www.longriflesinc.com
    Re: Threading Barrel ?

    I too have always made it a practice of cutting a crown whenever threading or working on a muzzle. It's set up anyway and I've done enough of them to know my way works.

    Nothing would suck more than taking a completed rifle (coated, blued, painted, etc) to the range only to find out the crown sucks and gun won't shoot.

    Now what? You have several more hours (dollars) invested into trying to fix a mistake with a rifle barrel that has finish on it. Now how do you hold onto it without fuggering anything up?

    Its darn near impossible.

    Even if you don't charge the guy for it, I'd still do it just to avoid a potential headache later.
     

    x ring accuracy

    Gunny Sergeant
    Full Member
    Minuteman
    Mar 28, 2008
    1,144
    3
    58
    Parrish, Fl.
    www.xringaccuracy.com
    Re: Threading Barrel ?

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Dixon</div><div class="ubbcode-body">I too have always made it a practice of cutting a crown whenever threading or working on a muzzle. It's set up anyway and I've done enough of them to know my way works.

    Nothing would suck more than taking a completed rifle (coated, blued, painted, etc) to the range only to find out the crown sucks and gun won't shoot.

    Now what? You have several more hours (dollars) invested into trying to fix a mistake with a rifle barrel that has finish on it. Now how do you hold onto it without fuggering anything up?

    Its darn near impossible.

    Even if you don't charge the guy for it, I'd still do it just to avoid a potential headache later.
    </div></div>
    Makes for good repeat customers. Standard proceedure in my shop.