Rechambering to 6mm AI

FALPhil · April 14, 2013, 12:03 PM

Yesterday, I found a really, really good deal on a Remington 788 in 243 Win. Now, I have no use for a rifle in 243 Win, but have always been fascinated with the 6mm Ackley. So, I was wondering, can I use a 6mm AI finishing reamer to "clean up" a 243 Win chamber for a quick conversion?

Looking at the chamber drawings, it appears so, but I would like to hear from someone who has actually tried it.

Thanks.

PVL · April 14, 2013, 05:30 PM

I would think that that would be an awful lot to expect out of a finishing reamer.

FALPhil · April 14, 2013, 05:34 PM

I have chambered 308 Win from scratch with a finishing reamer. You just have to go slow and use lots of oil.

mattL46 · April 14, 2013, 10:15 PM

My grandfather used nothing BUT finish reamers. And he said exactly what FALPHIL said. Cut slow and plenty of oil. He said it was always a better chamber.

F. Guffey · April 15, 2013, 10:34 AM

Yes you can, What can not be done is use the 6mm Remington reamer to clean up the 243 Winchester chamber, the 243 chamber is shorter, BUT! larger in diameter, same for the 308 Winchester when poor planning is used to chamber the 308 W to 30/06. The attempt will leave a portion of the shoulder/case body juncture, When cases are fired in the 30/06 chamber a ring will appear around the case body.

Then there is the neck, if both reamers have the same diameter neck, no problem, if the Ackely reamer has a neck that is smaller in diameter part of the neck in the chamber will have two different neck diameters.

Check the shoulder/case body juncture, the diameter of the case body at the shoulder juncture for the Ackley 30/06 is .455”. the diameter of the case body at the shoulder juncture is .454”. Then there is the neck on the Ackley chambers, it is longer.

F. Guffey

Jim Watson · April 15, 2013, 01:20 PM

Nearly everybody wants a repeater. If you do, be sure that a 6mm AI will fit into and feed out of the 788 clip.

A friend didn't care, he carved a block of walnut into a filler for the magazine well and contoured as a single shot feed tray.

April 14, 2013, 12:03 PM	#1
FALPhil Senior Member Join Date: September 10, 2007 Location: Racoon City Posts: 934	Rechambering to 6mm AI Yesterday, I found a really, really good deal on a Remington 788 in 243 Win. Now, I have no use for a rifle in 243 Win, but have always been fascinated with the 6mm Ackley. So, I was wondering, can I use a 6mm AI finishing reamer to "clean up" a 243 Win chamber for a quick conversion? Looking at the chamber drawings, it appears so, but I would like to hear from someone who has actually tried it. Thanks. __________________ _____________________________________________ Questions about 7.62 NATO and 308 Winchester? Click here.

April 14, 2013, 05:34 PM	#3
FALPhil Senior Member Join Date: September 10, 2007 Location: Racoon City Posts: 934	I have chambered 308 Win from scratch with a finishing reamer. You just have to go slow and use lots of oil. __________________ _____________________________________________ Questions about 7.62 NATO and 308 Winchester? Click here.

April 14, 2013, 05:30 PM	#2
PVL Senior Member Join Date: February 20, 2013 Posts: 169	I would think that that would be an awful lot to expect out of a finishing reamer.

April 14, 2013, 10:15 PM	#4
mattL46 Senior Member Join Date: February 9, 2013 Posts: 656	My grandfather used nothing BUT finish reamers. And he said exactly what FALPHIL said. Cut slow and plenty of oil. He said it was always a better chamber.

April 15, 2013, 10:34 AM	#5
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	Yes you can, What can not be done is use the 6mm Remington reamer to clean up the 243 Winchester chamber, the 243 chamber is shorter, BUT! larger in diameter, same for the 308 Winchester when poor planning is used to chamber the 308 W to 30/06. The attempt will leave a portion of the shoulder/case body juncture, When cases are fired in the 30/06 chamber a ring will appear around the case body. Then there is the neck, if both reamers have the same diameter neck, no problem, if the Ackely reamer has a neck that is smaller in diameter part of the neck in the chamber will have two different neck diameters. Check the shoulder/case body juncture, the diameter of the case body at the shoulder juncture for the Ackley 30/06 is .455”. the diameter of the case body at the shoulder juncture is .454”. Then there is the neck on the Ackley chambers, it is longer. F. Guffey

April 15, 2013, 01:20 PM	#6
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,539	Nearly everybody wants a repeater. If you do, be sure that a 6mm AI will fit into and feed out of the 788 clip. A friend didn't care, he carved a block of walnut into a filler for the magazine well and contoured as a single shot feed tray.