Used bolt, new barrel - Gunsmith?

[Sports-Ball]

I'm planning on having a used upper rebuilt (with unknown round count, though looks newish) with a new barrel. I'm going to have a gunsmith do the work and I'm not exactly sure what to ask him to do in order to check that the new barrel and used bolt are compatible. I'm vaguely familiar with the idea of checking headspace, is that what I need to ask him to do? Any other checks I should have him perform?

[GH41]

If you get both bolt and barrel from reputable suppliers headspace shouldn't even need checking. I wouldn't put the used bolt back in as cheap as quality BCGs are.

[markm]

Agreed. Unless one of the parts is really worn looking, you're fine assuming they're good parts to start with.

[Evil Black Rifle]

Have the gunsmith check head space, or buy your own barrel changing tools and head space gauges.

[grizzman]

I suggest using one of your new spare BCGs with the new barrel.

If you don’t have a new spare BCG, then buy a new BCG for the new barrel and make the used one an emergency spare.

[gunnerblue]

Rebarreling an upper isn't really gunsmithing, any reason why you don't just do it yourself? Headspace gauges are inexpensive

[DG23]

If you get both bolt and barrel from reputable suppliers headspace shouldn't even need checking. I wouldn't put the used bolt back in as cheap as quality BCGs are.

Agree about replacing the bolt along with the barrel but...

I would keep / reuse the same carrier he already has if it is in good condition as it is already mated to the upper he is reusing.

A new carrier is going to add a lot of wear to his used upper (while it becomes mated) for no good reason. The one he has already likely has a lot of miles left in it before needing any attention.

[utahjeepr]

^^^ This. A new quality bolt is cheap, keep the old one for a spare.

AR headspace ain't much of a thing. I have gauges so I use em but... I would imagine your smith will too, just cuz.

[georgeib]

^^^ This. A new quality bolt is cheap, keep the old one for a spare.

AR headspace ain't much of a thing. I have gauges so I use em but... I would imagine your smith will too, just cuz.

Agreed. By the time you've paid a 'smith, you could have just bought a new bolt and popped it in. That's what I'd do.

[lysander]

If its out, what are you going to do? What can a gunsmith do in this case that you cannot?