Rechamber 243 win to ?

S

Seanhagerty

Guest
I have a 243 win barrel. As a learning experience, I am toying with the idea of rechambering this to a 6br. I have never chambered a barrel or rechambered one for that matter. I have several questions about how to do this.

  1. Can I use a finish reamer to re chamber this?
  2. Can I do this by hand?
  3. Do I need to set the end of the barrel back to do this?

If I need to set the barrel back, I would rather try a different caliber. Can some one suggest a caliber that would allow me to use the exisiting barrel only reaming the chamber ? I would rather have a caliber that is fairly accurate and easily reloaded with available components. Long brass life would be a plus in the new caliber.
Any wisdom is appreciated.

Sean
 
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You could ream it out to 6mm with out cutting the barrel off. They say the longer neck on a 6mm keeps the barrel from burning out as fast ? Max
 
Starting with just one of your questions:

Seanhagerty said:
Do I need to set the end of the barrel back to do this?
Click to expand...

Yes. The 6BR is shorter by far than the .243. What would you do with the extra space?

By asking this question, you show that you've not only not done this kind of work before, but don't understand some very basic things. Ignoring accuracy, you'll be dealing with 50,000 pounds of pressure when you fire the rifle, and if the work is done wrong, that can literally kill you.

With that in mind, if there is a Community College nearby, take one or more machine shop classes. While it is possible to do some chambering operations by hand, the class would teach you the kinds of measurements and provide you a basic understanding you need, regardless of any machine-versus-hand labor.

And if the Community College classes are anything like what we have around here, you can use their machines after you complete the course. Be advised that there is a significant amount of math involved, but that's needed whether you "machine" with a lathe, or by hand. That's the really important part.

Sadly, most Community Colleges have to charge a significant fee for machining classes, to recover the costs they'll lay out. It is still one of the best deals around.
 
Charles E said:
Starting with just one of your questions:



Yes. The 6BR is shorter by far than the .243. What would you do with the extra space?

By asking this question, you show that you've not only not done this kind of work before, but don't understand some very basic things. Ignoring accuracy, you'll be dealing with 50,000 pounds of pressure when you fire the rifle, and if the work is done wrong, that can literally kill you.

With that in mind, if there is a Community College nearby, take one or more machine shop classes. While it is possible to do some chambering operations by hand, the class would teach you the kinds of measurements and provide you a basic understanding you need, regardless of any machine-versus-hand labor.

And if the Community College classes are anything like what we have around here, you can use their machines after you complete the course. Be advised that there is a significant amount of math involved, but that's needed whether you "machine" with a lathe, or by hand. That's the really important part.

Sadly, most Community Colleges have to charge a significant fee for machining classes, to recover the costs they'll lay out. It is still one of the best deals around.
Click to expand...

You are correct about my level of understanding as far a rechambering goes. That is why I am asking the questions.

The Community college idea is a pretty good one. I will look around.
 
I _think_ max.burgesse means that you could re-chamber it to accept the 6MM Remington cartridge without setting the barrel back???

Otherwise WTH???
 
It sounded like he didn't have aces to a Machine Shop. It not that hard to re chamber a 243 to a 6mm. Sorry Max
 
OK..... first of all, doing this sort of work definitely requires a machine shop and the necessary skill to use it and secondly, one must be capable of the requisite math AND have decent critical thinking skills.

For starters, just look at the dimensions on the drawings here of the 243 Win VS 6MM Rem and from these drawings FIGURE OUT whether or not the 6MM Rem can be used to wipe out an existing .243Win chamber.

http://www.6mmbr.com/cartridgediagrams.html

If you can't formulate a plan with this information in hand, please find a reputable gunsmith! :)

Al
 
Please max will you explain to folks like me exactly how you'll "easily" ream the .4308 shoulder diameter into the .4539 existing diameter of the .243 shoulder?

Is Kiff making smallifying reamers now?

Or does one just reverse the flow of the lube and suck the chamber down around the reamer? For us guys without a coolant flow system what do you suggest?

al
 
.244 AI (aka 6mm AI [Ackley Improved]). Nice round. I've had a couple. Wouldn't spend any money to make a functioning .243 into one though.

* * *

Actually, if somebody would put up a significant amount of money as a bet, I'd be willing to rechamber a .243 to 6mmBR.

You'd have to make, using hand tools, something like an old foot-operated sewing machine, but set up to spin a barrel, not sew. That would let you use a file, & you can take metal off that way.

You would need to purchase at least a die to thread the barrel. If you're good with a file, you might be able to do an acceptable shoulder, otherwise, you'd need a tap to make a nut (much easier to draw-file a true surface).

So, an expensive die, an expensive tap, and an expensive reamer. This on top of the measuring tools. A lot of hours. And unless you're really good with a file, not "benchrest" grade.

But if somebody would give me $50,000 if I could do it, it might be worth the effort...
 
Charles E said:
.244 AI (aka 6mm AI [Ackley Improved]). Nice round. I've had a couple. Wouldn't spend any money to make a functioning .243 into one though.

* * *

Actually, if somebody would put up a significant amount of money as a bet, I'd be willing to rechamber a .243 to 6mmBR.

You'd have to make, using hand tools, something like an old foot-operated sewing machine, but set up to spin a barrel, not sew. That would let you use a file, & you can take metal off that way.

You would need to purchase at least a die to thread the barrel. If you're good with a file, you might be able to do an acceptable shoulder, otherwise, you'd need a tap to make a nut (much easier to draw-file a true surface).

So, an expensive die, an expensive tap, and an expensive reamer. This on top of the measuring tools. A lot of hours. And unless you're really good with a file, not "benchrest" grade.

But if somebody would give me $50,000 if I could do it, it might be worth the effort...
Click to expand...

Shucks Charles, I could do that without all the drama. I would hog off the extra metal with a hacksaw, then file to fit. I've cut threads with a file too..... 3-4 wraps? Piece 'a cake.

And ditch the reamer idea, BR brass can be made to headspace tight in a 243, kindofa' reverse Ackley, just blow the neck forward.
 
Alinwa
I'm sorry I thought a 6mm Rem being longer 1.7807 verses 1.5598 would clean up the chamber. Sorry Max
 
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