Chamber reaming questions

When starting with just a blank barrel, I have always used a roughing reamer while the barrel is in the lathe to cut the chamber short.

Then after installation on the action, a finish reamer is used by hand to set the final headspace.

If I was doing it today I would just get a pre-threaded & chambered blank, install the barrel, and hand cut the final headspace with a finish reamer.

I always do my measurements first, to determine what head space should be on a particular receiver. I then cut to within .015 inches of the final measurement, recheck headspace (to see if my measurements are still correct) and cut 1/2 the remaining difference. I then install the receiver and finish by hand.

If you do it right (with a steady rest and a properly calibrated lathe), you can install the barrel hand tight, with the understanding that there can be up to .004 inches of crush. If you measure correctly, you may only have to hand ream .035" to achieve proper head spacing.

I have seen other ways to do it, but this always gives me the best results.

Clarification for us amateurs

ieszu, did you mean .035" for the final hand reaming, or did you mean .0035"?

ieszu, did you mean .035" for the final hand reaming, or did you mean .0035"?

Click to expand...

Sorry about that, I meant .0035"

The barrel is not removed from the lathe at any time during the chambering process. The tailstock is pulled back and the action with bolt is screwed onto the barrel periodically to measure the headspace. I've never seen a reamer long enough or a holder long enough to chamber through an action and wouldn't use such if there was one.

Same for rimfire.

Measure the desired length and then mark it slightly shorter on the reamer. Ream to that measurement and then assemble to the receiver. Headspace by hand turning the reamer.

I am confused. It seems most of the folks do what I used to do, but Mr. Roark says that is impossible.

(Today, I would use a pull-through for finish reaming, but we didn't have them in the old days.)

Jim

May be impossible, but that's the way I learned to do it at 5th. Inf AMU in 1968 building match & sniper rifles.
And that is the way I would do it today if I was going to do it today.

I still have the T-handle reamer extension & action pilots I made in the gunshop at 5th. Inf AMU.

I didn't say anything is impossible.

The OP question is that is the barrel removed from the lathe in the chambering process and can the action and barrel be chucked up and chambered through the action?

I think what the OP is getting at is that the action can be screwed on and off the tenon to check the progress of cutting the chamber depth. I have to admit that I never think of hand reaming so taking a barrel out of the lathe before I cut to final headspace never comes to my mind.

Anything is possible, I suppose. There are many ways to skin this how to chamber cat. I don't see the need to have pull through reamers for anything other than M1's. I don't have a problem with hitting a specific measurment to set headspace with my lathe under power. I chambered 4 barrels tonight. 2, 300 WSM and 2, 270 WSM's. The guy I did these for has a machine shop and wants to learn how to chamber, he had already threaded and fitted them to their actions. He had a guy come to his shop and do a barrel for him before. He said the way I do it is faster and so much easier than the other fellow. I was taught by the gunsmiths at the USAMU at Ft. Benning. They don't use T-handles on reamers. They use a Harrison Alpha 400.