I have read some where that the tailstock of the lathe should be setup different when chambering using a hand held tap wrench, vs turning on centers. If so, how should it be setup?
MR

since its early and no one else has awoke yet, possibly,I'll offer an answer. I'd say the only thing that comes to my mind is that I have used a live center to turn, between centers, but use a dead center,to keep my tooling straight during the cutting. The live center puts no wear on the center of the stock you are turning, which is singificantly faster than hand turning a cutting tool in a tap holder, but a dead center is usually more precise than a live center, and less bulky...maybe I should have waited till a guy that really knows the answer, gave it, then came along and said...yeah..thats it.....ha ha.....bob

MR---

If there's a difference I've never heard it.

There's a drastic difference if you're turning a taper, of course, but when turning *straight* sections between centers and chambering the tailstock is the same.......straight in line with the machine.

Does not make any difference if you are turning 40 foot ship shafting, chambering rifle barrels, or grinding 120,000 pound paper machine rolls, the tailstock has to be centered, aligned, no angular tilt of the ram, etc.

Holding the reamer is another matter. I use a premium floating holder that is designed for the machine shop trade, it is much higher quality than the small floating holders generally used by the gunsmith trade, and it works. I find least favor with the tap wrench method, used it in the past, but there are better methods to hold the reamer. I have tried about all methods of holding the reamer, and have setteled on a method that works best for me and gives good results.

I think that the statement is made because it is possible to set up and turn a true shaft with a flawde tailstock. That is, the talstock barrel can be angled up or down or sideways yet the center can be set in such a way that a shaft can be turned because the tailstock barrel is not moved during the process. Not so in chambering.
If a tailstock does sit at a bit of an angle it can be corrected but it may be necessary to pack a lunch! I have spent an entire day correcting worn tailstocks and had more that could be done yet.
Anyway, what is being said is that just because you are able to turn a true shaft between centers that doesn't mean your tailstock is properly aligned for chambering. Regards, Bill.

No difference in set up between turning on centers or cutting a chamber except for the means to hold and drive the reamer.

In lieu of a good floating reamer holder, I use a lathe dog and live center to cut chambers. With the bore and live center in my tail stock dialed in, I clamp the reamer in the lathe dog and place the "L" shape leg on the ways of my compound feed to provide lateral support, and as I advance the tail stock and reamer with my right hand, my left hand is in contact with the lathe dog so that I can "feel" what is happening as it cuts.

The hand wheel markings on my tail stock is incredibly accurate and I will use these with the markings on the ram to cut the majority of the chamber. When I get within .100 of final depth, I will swing a ram mounted dial indicator into play to make the final cut. Using this method, I can withdraw the tail stock and immediately take the reamer to the tank for cleaning between cuts. This also gets the reamer out of the way so that I can clean and inspect the chamber as I progress. All that is left is to relube the reamer, insert it in the chamber, ram up the tail stock and off I go...

Malm

[ 03-07-2003, 21:05: Message edited by: G.Malmborg ]

Thank you all for the input, thank you for all your informative posts.
MR

It's very interesting to read how others chamber.

I support the barrel in the steady rest on the threads (that were cut between centers) and hold the reamer with a tap handle with th tailstock center in the back and drive it with the tail stock wheel.

I spent a lot of money on a floating reamer holder and sold it cheap after 30 seconds of use. I like to feel the cutting steel and think I can identify any problems way before they become a *real* problem.

There are floating reamer holders and there are floating reamer holders!!!! The things sold for the gun trade are sort of useless, I have tried them all. They gather dust on the wall to remind me of bad money spent.

The one I use allows feel of the chambering process with the fingers of the left hand. Its a big thing, like I said above, it was made for the precision machining use, not the gun trade. Don't know what it cost, or a source, I think it is out of production. I bought it several years ago in a tooling auction at a machine shop closure.

Bad thing about using a lathe dog and resting it on the compound is you can impart a side load on the reamer and cut oversize chambers.

Like I said earlier, I have tried all common methods of chambering, and some that do not bear mentioning. I strive for straight, concentric, round chambers and I think I have gotten to the point of consistent results, but there is always another method to try that may be better than mine.

Chambering is like a gent's choice of a car or pickup: One man's chevy is poison to a ford owner. Just pick a method you like, and try to do good work. I chambered 6 barrels this week, got another one in the lathe now, so I have to think production also, this is why I use the pumped lubrication system for reaming, and some other things that speed up the job.

[ 03-08-2003, 00:37: Message edited by: John Ricks ]