Home Forums Hunting & Shooting Gunsmithing Muzzle Threading

Why use a dead center at all? With an extended live center that's turned down you have the perfect tool. The dead center having zero effect on accuracy depends on the person doing to job too. If he doesn't use enough grease on it or overheats the area and the grease runs off there is a potential for galling. I see no need to chance any of that.

We've pretty well beat the subject to death, but I thought I'd share the anecdote of a rifle just brought to me last week...a new Weatherby Camilla, 7mm08. Guy bought it for his daughter, it shot well with factory ammo, but she complained about recoil and started flinching. Without further thought (like loading down) he hauls it off to a gunsmith in the city for a muzzle brake. 250 bucks later it comes back, will not group, 3+ inch groups. So he hauls it to the village blacksmith...me. I am curious as to what went wrong so I started measuring stuff. The bore is not concentric with the bbl OD. Not horrible but around .0015. Lot's of bbls like that, no big deal, right? Measuring the screw on 1/2-28 brake (no brand name on it), the [bleep] thing is non concentric bad, like .004 out.
And now I suspect the 'gunsmith' cut the male thread on the bbl concentric with the bbl OD instead of the bore center. And then the 'gunsmith' cut the male threads pretty deep in the barrel...I'm estimating a hardware store fit of 60%...lots of wobble clearance. I don't know what's right, but if I was doing it I'd like to feel some interference as the brake was screwed on.
I guess this is a long way of saying little things matter, a thou here, a thou there...they don't add up, they multiply exponentially. So IMO there is nothing wrong with hashing it out in detail on a forum like this...to get better jobs in the end.
What am I going to do for my customer? Make a thread protector, develop a 120 gr light load that is accurate, and tell him to forget the brake.

Another simple work around is to turn a bushing to press onto the barrel and use that for steady rest contact.

If you want a low clearance threading tool, use a parting tool and gring to profile.....just dont get greedy on the cuts as it lacks side to side rigidity.

You can turn a "pipe" with two sets of set screws to allow jacking into square/concentric. Grab that with your 4 jaw and a steady....rock on.


Lots of ways to burn the hair off this cat.

They do add up. That's why learning to work to the utmost in perfection is just a good work habit to develop.

This is similar to the route I plan to take. First, I'll make new brass bearing surfaces for my steady rest. That is, if I can't find roller bearings that will fit it.

This is where I got mine.
https://www.mcmaster.com/products/bearings/

Been away working up north. Thought I'd asked at the time, apparently didn't. Pure curiosity.

When one is set up like shown in this picture and the threads are complete, what about the crown? Have you cut the crown previously, doing it afterwards or what? Of course I am not talking about a thread only job. Say you were to cut to length, crown and thread. Say a recessed target crown or even an 11°.

Understanding there's many ways and often things can be plenty good enough to get'r done for the intended purpose.