Gunsmithing Whats the deal..?

[xdeano]

We've got this crazy surge in accuracy lately. Weve got great ammo companies coming out with great new products, powders, excellent new bullets, wild scopes/range finders and all the crazy cut rifled barrels that come in such a variety of flavors, they all cater to our precision fantasies.

So what's the deal, we take that great single point cut rifle barrel, stick it into a lathe or cnc and chamber it with with our chosen reamed that we've been doing for a century. It's a great way to kick out barrels, sure, but there has to be some error in this process.

I'm not a gun Smith, I'm just throwing out an idea.

Why haven't guys gone into that single point chamber. Take a known precision cut barrel, chuck it into a cnc, use a drill bit to get the initial chamber close, then swap out to a single point cutter and get a precise chamber to the spec every single time, no chatter, no wondering, nothing but precision. Thats what were after isnt it?

Ive only heard of one Smith that has done this. With excellent results no less. It can be done.

Is it going to be slightly slower, sure. Instead of 7 minutes to chamber, it might take 14. I dont know the specs on how long it would actually take, but I was told that using the reamer method it takes roughly 7 minutes to chamber and cut tendon.

Is the joice worth the squeeze?

Xdeano

 

[bohem]

The issue that typically comes up from this approach is "how do you qualify the chamber shape once complete?"

I've done it as well, actually using a duplicate of the boring bar from the builder you're probably talking about. The programming time was cumbersome for him. I have a macro program setup that allows a user to read a print, input about 2 dozen variables and then let the machine drill, prebore, and finish bore the chamber. Total time runs a little south of 8 minutes on a CNC that has a toolpost not a turret.

What actually seems to work the best so far is to rough out the chamber and then run the reamer in to finish up all the internal surfaces so that sharp corners are sharp, radii inside are indirectly inspectable through inspection of the reamer, etc.

The headspace gage actually tells very little to the user. The application of gage balls, pin gages, and indicator tracing takes a lot more time to inspect the chamber and without the programming skillset to write a configurable macro program it takes a while to piece down each program unless you're coughing up for a CAM package.

 

[DAVETOOLEY]

I have a friend who did it with good results. Time consuming programing, expensive tooling, finishes will have to be addressed. No advantage to it other than being able to say you did it. With that being said that's the process for making all the custom dies being made on an individual basis. The quantity drives down costs and you're not talking about the lead angle in a precision barrel. It's three surfaces in a sizing die that relate to each other. I would probably do it where only two surfaces mattered. That's pretty simple and easy to do in a die body.

 

[xdeano]

I just feel that it's strange that were doing single point on rifling in precision tubes, but nothing is said about clambering. It can be done, so why not prove that it isn't worth the squeeze.

It might take longer blah blah, but if it can provide some sort of usability. Think about if single point proves to be more accurate then conventional reamers for elr shooting. It could be a big deal if they can dial in a chamber.

I love to hear some data.

Xdeano

 

[xdeano]

Bohem,
I'm pretty sure you know the guy I'm talking about. Ive seen the boring bar and the program in person. The end results on his chamber is impressive, and I feel it help in accuracy. He shared with me how accurate it was. The cnc overlay drawings were wild.

Its a pretty neat setup.
Deano

The issue that typically comes up from this approach is "how do you qualify the chamber shape once complete?"

I've done it as well, actually using a duplicate of the boring bar from the builder you're probably talking about. The programming time was cumbersome for him. I have a macro program setup that allows a user to read a print, input about 2 dozen variables and then let the machine drill, prebore, and finish bore the chamber. Total time runs a little south of 8 minutes on a CNC that has a toolpost not a turret.

What actually seems to work the best so far is to rough out the chamber and then run the reamer in to finish up all the internal surfaces so that sharp corners are sharp, radii inside are indirectly inspectable through inspection of the reamer, etc.

The headspace gage actually tells very little to the user. The application of gage balls, pin gages, and indicator tracing takes a lot more time to inspect the chamber and without the programming skillset to write a configurable macro program it takes a while to piece down each program unless you're coughing up for a CAM package.

 

[LRI]

We've got this crazy surge in accuracy lately. Weve got great ammo companies coming out with great new products, powders, excellent new bullets, wild scopes/range finders and all the crazy cut rifled barrels that come in such a variety of flavors, they all cater to our precision fantasies.

So what's the deal, we take that great single point cut rifle barrel, stick it into a lathe or cnc and chamber it with with our chosen reamed that we've been doing for a century. It's a great way to kick out barrels, sure, but there has to be some error in this process.

I'm not a gun Smith, I'm just throwing out an idea.

Why haven't guys gone into that single point chamber. Take a known precision cut barrel, chuck it into a cnc, use a drill bit to get the initial chamber close, then swap out to a single point cutter and get a precise chamber to the spec every single time, no chatter, no wondering, nothing but precision. Thats what were after isnt it?

Ive only heard of one Smith that has done this. With excellent results no less. It can be done.

Is it going to be slightly slower, sure. Instead of 7 minutes to chamber, it might take 14. I dont know the specs on how long it would actually take, but I was told that using the reamer method it takes roughly 7 minutes to chamber and cut tendon.

Is the joice worth the squeeze?

Xdeano

I was chastised and ridiculed for it by the BR crowd 15+ years ago when I started it. Some still fail to make the leap of what is possible.

I'll put it like this: If you are willing to take your Mom, wife, kids, dog, cat, etc... on an airplane to your chosen vacation spot, as in "trust your lives" to all those parts made via automation, then your bolt action will be just fine.

The process is proven and its vetted. Has been for a decade an a half now. It comes down to setup and process. The machine just does what its told.

Single pointing a chamber turns into an expensive joke. Depth of reach kills tool rigidity. It's been done on short stuff, but trying to chamber a 338LM or say a 260 Win Mag, well.... I'd rather play in the street with dull razors during heavy traffic.

Using a conventional form tool: The tooling geo is the key. Stick to what's been done and you'll become rather frustrated very quickly. Explore the process and doors open up. I've spent over $100K doing just that. The reward is a 308 length case in 48 seconds. -yeah, I just said that.

Experience never comes cheap.

C.