Rechambering 6BR to 6x47L

W

Walt Collins

New member
I have a new BAT VR action on the way and want to chamber a new Krieger barrel for 6BR. My aim is to use this rifle as a repeater, but, if I can't get it to feed right, I want to rechamber it to 6x47L. I've overlaid the drawings of the chamber reamers (PTG drawings) and they are virtually identical up to the body and shoulder juncture. That dimenision at that point is less than .0001. Am I correct in saying that a 6BR chamber could be recut to 6x47L without setting the barrel back any? Also could a barrel be chambered as 6BR and then rechambered to 6x47L using the 6BR reamer. My guess is no since the 6BR has a longer neck. Any help straightening me out would be appreciated.
 
I absolutely know that in some cases it works..... in fact I've used a 6BR reamer to chamber a couple 6X47L's.... ;)

You're right about the neck, the new 6X47L chamber be long enough to exceed the length of the old neck.

al
 
Walt, I checked my reamer prints and the main difference between the 6 BR and the 6x47 Lapua is that the neck is a little longer on the 6 BR. If you run your 6 BR reamer into headspace on the 6x47 Lapua, you're going to wind up with a chamber that has a little longer neck than the 6x47 Lapua cartridge. Also, as you run the reamer in farther, the base of the chamber is going to open up larger at the .200 datum line as the taper on the reamer keeps going.

My reamer print shows the following:
6 BR .272" neck .471" at the .200 datum line, .461" at the shoulder, neck length is .335".

6x47 Lapua .269" neck, .472" at the .200 datum line, .4578" at the shoulder, neck length is .2972"

You'd wind up with a chamber that roughly measured .475 to .476" at the .200 datum line with a neck .038" longer than a 6x47 Lapua chamber.

It would work for a one off chamber, but if you are going to chamber more than one of them, I'd get the correct reamer.

The 6 BR chamber should clean up with a 6 x 47 Lapua reamer without having to set the barrel back. My reamer specs above are for custom reamers made to my specs, so there may be a little difference between chambers.
 
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Good news!

I think I have the correct idea based on you fellow's replys. I would imagine the 6x47L reamer would follow that BR hole right up the alley! If so, it is unlikely it would leave a line at the old shoulder junction. It would be nice to use a BR die that is a couple of tenths less at the shoulder to be on the safe side.
I appreciate your expertise.
Walt
 
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