Thinking out loud...single point cut chambers?

[JJMoody]

So I'm watching various precision loading videos and the topic of custom dies was Up. The guy (very well known and respected on this forum) was showing the Warner custom die and the precision with which they were built using single point cut machinery to the finest of tolerances. Admittedly, I'm no machinist, nor do I possess anything remotely resembling aptitude towards gunsmithing, but the thought came to me that if single point cut custom dies produce amazing results, why not cut the chamber in the same way? Eliminate the need for multiple reamers and all that, simply (remember my previous disclaimer).. simply program the machine to cut the chamber to whatever spec is written into the program. Is this just plain idiocy or brilliance?

 

[shortgrass]

You're way behind the curve, JJ. There are several who are already cutting chambers with single point tooling. But, consider this. A used TL1 wll run $20,000 to $28,000. Then you have to tool it. Besides understanding machining principals, you need to have the knowledge to program. You might buy a CAD program that would/could generate programs for you. You'd have to chamber a lot of barrels or have other work for that TL1 to do to make it pay. For around $5000 to $7500 you can set-up a manual lathe for chambering,,,,, a nice one. That is machine and tooling (good lathe chucks, good QC tool post and holders, drill chuck(s), live centers, etc). That leaves $12,500 to spend on reamers (over the $20,000 you might spend on a TL1). That's a lot of reamers! And, when used properly, they rarely need to be resharpened or replaced. I can pretty easily chamber 4 rifle barrels, and fit, crown and headspace them, in an 8hr day (depending upon how many interruptions I have in that 8hrs). There's more to gunsmithing than chambering and glass bedding. Pick your poison!

 

[JJMoody]

Shortgrass, I truly do appreciate your confirmation of my lack of understanding of the the basic fundamentals, I knew I'd get something right today! The question was a bit of an afterthought of wondering how they make custom dies off of your fired brass, finding the answer and fumbling my way through alternative uses for existing equipment (without thought or consideration of tooling costs). In retrospect, one could liken my thought process to an aspiring "interior designer " scrolling through pictures on Pinterest, thinking, "hey, I bet I could do that..." now assuming one had the tooling, CAD software, knowledge etc, would it be a viable option? Aside from the negative aspects of what was mentioned earlier, along with the less than desirable hands-off approach towards craftsmanship that could result in a brand new plug and play "gunsmith " cranking out prefit parts on his new toy, what could the upside be?
On a side bar, I've always appreciated the shared knowledge of yours and a select few others on the gs part of the forum.

 

[shortgrass]

The guys that are making custom dies using CNC must be busy to justify the costs involved. Maybe they have 'other' work for their machine tools to keep them busy. Many view 'gunsmithing' with the new, hands off approach.One after another with little variation from rifle to rifle. Making sizing dies using fired brass would mean just making slight changes in the program for each job, after careful measuring with a "shadow graph" (properly called an optical comparator). The 'craftsmanship' is now in the machining, with little emphasis placed on the one at a time hand work. Hand work leads to "individuality", as no 2 that are made or fashioned with human hands can or will be identical. This is what I see on most of the gun related on-line forums. One place where hand work can be seen/viewed is on accuratereloading.com. Several well known stockmakers post there. Every now and then they post pics of their work. Not just stock work done by hand, but metal work, also. I see some neat ideas there occasionally. Last spring, at the Wanenmacher Tulsa Arms show, I got to view and was allowed to handle a .458 Lott that was built by a well known stockmaker/gunsmith. Flawless! Not a gap in the inletting, not a flaw could I find in the slow rust bluing, not an over-run in the hand cut checkering. Scope mounts made in his one man shop and polished by hand before bluing. All hand work, done in the 'traditional' way, with no CNCs involved. The price tag said $7500. It was sold by the end of the show. Craftsmanship. It amounts to self control. The ability to focus on the work at hand, and to carefully do it. "Make the hands do what the mind is telling them to do".

 

[JJMoody]

I completely agree and understand this. I actually make my living as a jewelry and leather artist, (used to fight and rodeo professionally, now I make earrings...lol!) the craft is not lost on me. I guess the viability question was answered. Possible, but something is definitely lost in the process.

 

[shortgrass]

I wanna' be there to see (and hear) the boring tool that cuts the neck and throat on a 7MM STW or similarly long cartridge. That's hanging a small diameter boring tool out of its holder a long ways and then having to deal with the interrupted cut of the rifling. Hanging any cutting tool out farther than it need be, or further than it can cut without deflecting from the work, is asking for deflection and chatter. Shorter cartridges, like the 6BR Norma, wouldn't present the same tool over hang problems. That said, there have been huge advances in tooling and tool holding that I probably haven't seen yet.

 

[KyCarl]

Machine Tools are super expensive! I ran a Fauuter Gear Hob that cost over a million bucks! The Hobs (cutters) were so expensive that we Rented odd sizes rather than buy them.

 

[shortgrass]

The "up side" of CNC manufactured 'parts' (dies, gun parts, cutting chambers) is lower cost per piece and repeatability. Also, the ability to easily make minor changes in the dimensions of the 'part' being cut. A lot of 'product' has to come off of a CNC before the profit begins, and tooling is always an on going expense. Also, the 'repeatability', the machine never gets tired like a man can. As an 'automatic', 1 operator can be responsible for 2 machines at a time. Where as with a manual machine 1 man = 1 machine.

 

[Canadian Bushman]

I think id still prefer to have my chambers reamed. Wouldnt take much to disturb the lay on a single point finish cut by a little bar, in a little hole. God forbid the bore isnt running true. That little boring bar aint gonna follow it.

Chamber reamers cut pretty nice without much effort, and they are piloted.

 

[JJMoody]

Copy that!

 

[Gord0]

I've single point cut a chamber on a manual lathe just to prove I could. It was 45acp, so about the easiest chamber you could cut. You would need all sorts of special tooling for cutting rifle chambers which would cost a fortune. A reamer is cheap, precise, and will give you a better finish every single time. Unless you get into internal CNC grinding, which is a whole different animal, but would get you more precision, and better finish than reaming.