Chamber reamers, how do these work?

[bikemutt]

I'm just curious and figured I'd ask about how chamber reamers work.

I stumbled onto the Grizzly.com website that show reamers and hand tools for their use; are these gunsmith tools or can anyone use one? What sort of barrel would be ready for a chamber reamer?

[DHuffman]

Anyone can use them LOL but they're best used with a blank barrel indicated in a large.

I've got a small collection of them but lost the lathe I was storing before I got up the nerve to run one in.

Randy is pretty adept at using them without the benefit of a large so it's not mandatory.

[gman47564]

Dave is there a pilot shaft in the end of the reamer to keep it inline with the bore ?

[mnbogboy]

CHRIS, there are solid pilot reamers & bushing style reamers where the bushing can be replaced with  different bushings to match bore diameter. My reamers are all solid pilot where the pilot itself is a precision ground diameter when the reamer itself is being ground. We assume they are all ground with CNC equipment. I use a tap handle to turn mine as the end opposite the pilot is square . The flutes are pretty much razor sharp after grinding and leave an almost mirror like finish when they cut. As Dave said, In a lathe the bore must be indicated true to the axial position of the reamer holder. The tailstock in the lathe is used toadvance the  the reamer into the bore
My crudimentry method is to push downward on my tap handle as i stand above it. My barrel vise is mounted vertically approximately 1-1/2 feet above the floor. I have a 5 gallon bucket placed under the vise to catch cutting oil, chips and cleaning patches.
Cleaning the bore, chamber and reamer is very important after every "cut"/pass. I also measure progress each pass/push with a depth caliperand the go gauge. Each cut can vary from .010 to .050.
THE stainless barrels seem to cut easier than others.
Keep in mind these are all rechambered or ackley improved on existing chambers. It would be a huge blister producing job to do a complete chamber in a new bore. The Teslong has proved to be the best before and after tool for each chamber. The reamer will follow the old chamber as far as concentricity goes. If you've  researched this very much you will find a lot of scoffers among the experienced smiths.
Good luck if you try it and don't be afraid to ask questions. I can take some pictures if you'd like.

[DHuffman]

Dave is there a pilot shaft in the end of the reamer to keep it inline with the bore ?

Yes either solid like Randy said or live as in a pilot bushing attached to the reamer but allows the reamer tip to rotate inside it.

[jvw2008]

Chris like you I have no personal experience with this process other than to watch the job being done by a couple of very good gunsmiths. It's my understanding that the quality of the job is initially determined by how well the barrel is indexed to the lathe. If memory serves, the job is more difficult but also more exact, when the bore of the barrel rather than the outer perimeter is used to true it up in the lathe.
At one time I seriously considered getting the equipment and learning how to ream a chamber. After watching the process I decided it was one of those learning curves and investments that was going to detract from my devotion to shooting time. It's a skill that broaches on an art to produce a masterful job. I will leave it to the pros and concentrate on the finer points of reloading. ?

[gman47564]

Plus when buying a blank then theirs always threading it for the action as well.. if im not mistaken as i have never bought just a blank..

[DHuffman]

Plus when buying a blank then theirs always threading it for the action as well.. if im not mistaken as i have never bought just a blank..

Correct as well as shouldering and crowning. The throw in the job of indexing the barrel so it's pointing up as opposed to left right or down and getting the case to headspace in this position and it seems like a lot. LOL

[bikemutt]

Thanks guys!

[mnbogboy]

The location and amount of chips in the flutes will yell you a lot about the reamer as you proceed. Chips tell you how and where it is cutting the best.