Critique my Threading and Chambering - Video

[Mram10us]

This is my way of threading and chambering, but would like to see other videos you guys have made on your techniques. Works for me, but I'm sure my process can be refined. This was a 7-08ai I built a while back.
What do you do different and why?

 

[livetohunt]

I prefer the "sitting at a computer and then pressing buttons on the machine" method! But that's just because I've grown up with CNC's.

I like your tool storage location there above the chip guard.

 

[Mram10us]

My wife would use one of my rifles to off me if I spent $50k on a Cnc

 

[tobnpr]

Maybe my eyes deceived... looked like you cut the bolt nose counterbore (with the form tool) rigidly held in your drill chuck- and didn't use the floating holder/reamer that I see in the drill chuck when you start the chamber? If so, you could end up with some misalignment of the counterbore. I wouldn't treat the counterbore reamer any differently than the chamber reamer.

I use a micrometer reamer stop, but absent that- consider using your carriage with your micrometer carriage stop as a "hard stop" for your carriage/tailstock. I used this method briefly, before I went to using the micrometer stop.

Looks like you're backing out the whole shebang, then just running the reamer back in until you feel contact each time, then calling that "zero" again. As you've no doubt found out- trying to get a thou this way can be extremely hit and miss depending on the pressure needed for the reamer to begin cutting.

When you get close, push the tailstock hard against the carriage (some guys fab up tooling of some sort to actually attach the tailstock firmly to the carriage). Set your Z axis zero. Hands off the tailstock handwheel... if you have a loose one, make sure the screw won't move in or out by itself.

Advance the reamer by using the handwheel on your carriage, dialing the micrometer carriage stop to exactly what you want. By having the tailstock locked to the carriage- or pushing it by hand (loosen the tailstock bed clamp just enough to slide it, like power tapping) and moving as one, when you back out and come back you'll be exactly where you were- plus whatever adjustments you dial on your carriage stop.

You didn't go much into detail on your method for dialing in, so can't comment on that. I'm assuming you traversed at least several inches of the gauge pin to be sure it was running true. Not saying what I do is any better, but I concentrate more on the throat area (with a Grizzly rod), moving the bushing directly to where the throat is to within a tenth- then the very back of the chamber as close to that as I can get with the outboard spider.

Just some food for thought...

 

[Mram10us]

Maybe my eyes deceived... looked like you cut the bolt nose counterbore (with the form tool) rigidly held in your drill chuck- and didn't use the floating holder/reamer that I see in the drill chuck when you start the chamber? If so, you could end up with some misalignment of the counterbore. I wouldn't treat the counterbore reamer any differently than the chamber reamer.

I use a micrometer reamer stop, but absent that- consider using your carriage with your micrometer carriage stop as a "hard stop" for your carriage/tailstock. I used this method briefly, before I went to using the micrometer stop.

Looks like you're backing out the whole shebang, then just running the reamer back in until you feel contact each time, then calling that "zero" again. As you've no doubt found out- trying to get a thou this way can be extremely hit and miss depending on the pressure needed for the reamer to begin cutting.

When you get close, push the tailstock hard against the carriage (some guys fab up tooling of some sort to actually attach the tailstock firmly to the carriage). Set your Z axis zero. Hands off the tailstock handwheel... if you have a loose one, make sure the screw won't move in or out by itself.

Advance the reamer by using the handwheel on your carriage, dialing the micrometer carriage stop to exactly what you want. By having the tailstock locked to the carriage- or pushing it by hand (loosen the tailstock bed clamp just enough to slide it, like power tapping) and moving as one, when you back out and come back you'll be exactly where you were- plus whatever adjustments you dial on your carriage stop.

You didn't go much into detail on your method for dialing in, so can't comment on that. I'm assuming you traversed at least several inches of the gauge pin to be sure it was running true. Not saying what I do is any better, but I concentrate more on the throat area (with a Grizzly rod), moving the bushing directly to where the throat is to within a tenth- then the very back of the chamber as close to that as I can get with the outboard spider.

Just some food for thought...

First, thanks for taking the time. Good techniques. I use the counterbore tool in the tailstock because I check my tailstock alignment often. I have done it both ways but like the idea of it not floating v set in the TS since it's properly aligned.
I like your idea of the carriage. Seen guys use the carriage with a floating reamer in a tool holder. I'm not sold on that but your idea seems interesting to me.
Taking the reamer all the way out allows me to make sure no chips are there. Finding zero with the TS loose then tightening has worked for me, but I'm sure there is a better way.
Dialing in with range rods and I tight fitting bushing is all I do. Makes sense to me since the tight fitting pilot is in the throat area of the barrel. Again, I'm sure there is a better way

 

[tobnpr]

Nope, not a better way. Just different ways, many ways to do this work- and much of it, while it may make for interesting discussion, doesn't convince me it translates at the target. These days, you're called a hack online for chambering between centers....some "strong" opinions out there, right?

But I am curious about your explanation for rigidly holding the counterbore (I use them too...faster and more precise than I can bore). If you're convinced your tailstock is perfectly aligned, why not just keep the same approach for the reamer?

When I would really dig into the subject of machine tool alignment I found it's very complex, and above my pay grade

 

[Blancoalex]

One thing I do for bolt recess is cut with undersized size end mill in tail stock and then finish with tool bit as everything running true. Of course your piloted guided cutter is quicker. Thanks for sharing video.

 

[Mram10us]

Nope, not a better way. Just different ways, many ways to do this work- and much of it, while it may make for interesting discussion, doesn't convince me it translates at the target. These days, you're called a hack online for chambering between centers....some "strong" opinions out there, right?

But I am curious about your explanation for rigidly holding the counterbore (I use them too...faster and more precise than I can bore). If you're convinced your tailstock is perfectly aligned, why not just keep the same approach for the reamer?

When I would really dig into the subject of machine tool alignment I found it's very complex, and above my pay grade

Between centers!? Sheesh
Since the counterbore only has to follow a ~.150" hole, I'm not as worried if it is off by .001" even though mine isn't. I might be missing something. With a reamer, I figure I need a little flexibility when following 4" of bore.
To be honest, I don't know why I even do a counterbore anymore. A lot of guys don't on rems

 

[25WSM]

I still do the counter bore but then I take half of it out with a 30 degree cut. So it is sort of a hybrid of a coned bolt. Still has a ring of steel around part of the bolt nose and has 30 degree ramps for better feeding.
I don't use floating holders of any type as I too keep my tailstock properly aligned. I took mine and had it ground on a precision bring tool to the proper height. Now all I need to do is keep it in the center. Mine came about . 005 to high when I bought it. I check my ways and tailstock all the time to make sure I'm still straight.
Shep

 

[25WSM]

As far as doing barrels between centers I know Greg Tannel does his that way and his gun broke alot of records. When I went to gunsmith school between centers was the only way we were taught. I use range rods and do them in the headstock now. It's just a much more rigid setup.
Shep

 

[aushunter1]

I have no idea what you were doing but now I know why I pay a guy to do it for me

Just a couple of placed on the vid where the view was obstructed & your voice drowned out by the noise of the press.

Other than that I enjoyed looking into a process I have been curious about for a long time

 

[Mram10us]

I have no idea what you were doing but now I know why I pay a guy to do it for me

Just a couple of placed on the vid where the view was obstructed & your voice drowned out by the noise of the press.

Other than that I enjoyed looking into a process I have been curious about for a long time

I am noooo cinematographer.... whatever that is

 

[ThrdKllr]

There's no reason to use a floating reamer holder for the counter bore reaming tool. With it held rigidly, even if it is off.010 it will just make the counter bore .020 bigger in diameter since the barrel is rotating. I drive my reamer with a live center in the tailstock but I make sure my tailstock is perfectly aligned. Lots of ways to skin a cat without getting hair on the meat.

 

[25WSM]

Dam I always get hair on the meat. Once you get used to the texture it's no big deal.
Shep