Head Space on a Prefit Barrel

[centershot]

I understand the concept of this. Without having the reamer that chambered the barrel, can head space be adjusted? If it is too tight, I would think you would need the reamer to take metal off of the shoulder part of the chamber. What do you do if it is too loose? Cut another turn of the thread? Can any of this be done without a lathe?
Thanks in advance.

 

[DaveTooley]

The only thing you could do by hand is deepen the chamber using a chamber reamer. Better the reamer that was used to chamber the barrel. Then you get into the question of chamber finish.

Now with that being said as long as there is not an unsafe condition with the case head being exposed short or long doesn't matter as much as you think. If short and ammo fits in the chamber you're good. If the chamber is a bit deep you're good. The reason is we fireform the brass to fit the chamber and set the FL sizing die to match the chamber. If however you're going to run factory ammo all the time you could have problems with chambering a round on a short chamber and misfires on a chamber that's too deep.

 

[jelenko]

By 'prefit' are we talking about a barrel with a nut or a shouldered barrel?

 

[centershot]

Without a nut.

 

[Walt Krafft]

A shouldered prefit is not adjustable without adding or sutracting material someplace. If it has a recoil lug it can be ground down or a thicker one used. We are not talking much. The difference between go and nogo is only 4 to 6 thousanths on most cartridges.

 

[jelenko]

I think I'd want to talk to the seller of the prefit if it didn't headspace properly.

 

[NZ_Fclass]

I don't think that a "pre-fit" is a DIY project, unless you have the tools and gauges to fit it. Better a gunsmith screws it on. If it was a "nut" barrel, it's a lot easier, but you really should have a "go" and "no-go" gauge.
As the earlier posted suggests, metal has to be moved somewhere.

But just what is the issue/action on your rifle?

 

[NorCalMikie]

I think I'd want to talk to the seller of the prefit if it didn't headspace properly.

So, what IS the "proper" headspace?? You determine what fits YOUR chamber. Too short? You have dies to change the size of your brass. Same goes for too long. It's YOU that controls what is and what isn't.
Maybe .001/.002 or .003 difference? It's a custom anyway. You going to be using factory loaded ammo?? My guess, probably not.
Chambered to SAAMI specs? (sloppy at that)
Not one of my rigs will chamber factory loaded ammo. (except my gas guns)
SAAMI, minus the extra slop.

 

[centershot]

I was contemplating buying a barrel on this site that was chambered and threaded for a Remington 700. The gunsmith that I use only wants to chamber the barrels himself. I am sure he does not have the reamer. Just trying to pick other peoples' brains.

 

[Walt Krafft]

Buy a blank and have your gunsmith rent a reamer.

 

[DaveTooley]

I was contemplating buying a barrel on this site that was chambered and threaded for a Remington 700. The gunsmith that I use only wants to chamber the barrels himself. I am sure he does not have the reamer. Just trying to pick other peoples' brains.

700's will be all over the place when it comes to HS and thread fit if the action has been trued. Plan on it requiring some work and budget for it.

 

[LVLAaron]

In other words, don't do it.

 

[Migolito]

I mentioned this on another thread, please excuse the repost.
I have a Howa that was squared, lapped, etc. So, that does change the HS a wee bit. When I rebarreled, I used a Preferred Barrel (https://preferredbarrelblanks.com/) prefit, with the nut. The install was stupid easy. I rented the guages (https://www.reamerrentals.com/searchresults.asp?cat=26) and installed the barrel myself. Did I say it was easy! It is a .25 shooting barrel. Very very nice quality barrel.