barrel threading & crowning

[trex]

When you have your barrel threaded do you have it crowned or just leave it factory?
Anyone know abought how much it might cost to thread a barrel still on the rifle?

 

[MUP]

Pretty sure the barrel needs to be removed in order to thread it on a lathe.

 

[Wiley]

Pretty sure the barrel needs to be removed in order to thread it on a lathe.

Yep. It has to be centered on the bore, not the outside dimension of the barrel. I sent a Remington 700 barreled action to ADCO in Illinois for my only barrel threading on a centerfire. For gunsmithing such as this, the weapon can be sent by its owner and the gunsmith ships directly back to the owner with no FFL involved. My rimfire rifles that are threaded were done at the factory as production for that particular weapon.

Against my advice, a friend bought a threaded barrel off eBay for his 10/22. It was cheap, as was he, until it destroyed the baffles in his suppressor on the very first shot.

 

[Remi]

When you have your barrel threaded do you have it crowned or just leave it factory?
Anyone know abought how much it might cost to thread a barrel still on the rifle?

Give LRI a call. They don't have to remove to thread

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[Jcalder]

When I had my rifles threaded back in the summer of the barrels were over a certain length they didn't have to remove the barrels.

 

[tahtah]

I have one I'm planning to have threaded. What is crowning?

 

[Wiley]

I have one I'm planning to have threaded. What is crowning?

The crown is the beveled edge of the bore at the muzzle end where the bullet leaves the bore when fired. It's crucial that the crown be evenly cut and maintain whatever angle it has all the way around the bore and without any leftover burrs from being cut. An uneven/damaged or otherwise less than perfect crown will cause issues with accuracy, sometimes minor/sometimes major.

 

[tahtah]

Thanks. Wouldn't a competent gunsmith be sure to maintain that as standard procedure? Or is it something one needs to ask about along with the threading?

 

[Wiley]

A pointed pilot, larger than the bore diameter, and mounted into the jaws of a lathe, has its point inserted into the crown (think of a sharpened pencil here) when threading. This is how the threading is done concentric to the bore instead of based on the outer diameter of the barrel which is most often off center from the bore. So, I would assume that a competent shop doing the threading would at least inspect the crown after threading. I believe that recrowning was part of finishing the process and written into the description of the threading process at ADCO when I had my rifle done. If not specified by the shop it wouldn't hurt to ask.

 

[Mausermeister]

Re-crowning should not be necessary unless you are having the barrel shortened or the crown is already damaged, or maybe you want a recessed crown or different angle. Depending on the action, it may or may not be necessary to remove the barrel to thread it. I've threaded a few of mine on my old lathe. Using a live center makes it concentric with the bore.

 

[rifle02]

When I had my rifles threaded back in the summer of the barrels were over a certain length they didn't have to remove the barrels.

That's generally true depending on the lathe setup. If the barrel is long enough to thread through the headstock, no it does not need to be removed.