6mm rem AI question

[MildBill]

Is it possible to rechamber a barrel from regular 243 Win to 6mm rem Ackley?

I been thinking about doing this to a Rem 700 that I have that had less than 1 box of shells though it. My intended use would be for reaching out to putting a serious thumping on coyotes.

It is a real shooter , in that it cloverleafs the 80 grain powerlokt factory load just the way it is now, and perhaps I would be better to leave it be, but the 6 rem Ackley really intrigues me.

 

[chrisj]

Yes. But not the standard 6mm Rem.

Chris

 

[therifler]

i have made several 6mm ack and tried to convert 243 chambers on one or two . you must shorten chamber end of the barrel in order to make a good 6mm ackley chamber. if you look at the prints and compare chamber sizes you will find that the win is just a few thousands of and inch larger then the 6mm ack . unless you shorten the barrel on the chamber end it does not ream away the 243 chamber entirely .

 

[1000yardstare]

I had a 6/250 that I wanted rechambered to 6AI. The 6/250 is a shorter cartridge than the .243. A gunsmith with a good rep said he had to shorten the chamber end of the barrel before he would rechamber. The .250/.243/6mm all have the same head diameter. On paper it looks like a rechamber job should work but if the original chamber is a bit sloppy then there is a problem cleaning up the metal at the rear of the chamber. So I put on a new 6AI barrel.

 

[MildBill]

sounds like I would be better served to make the current barrel into a 243 AI if I wanted to ackley it, and rebarrel for a 6mm AI.

I prefer to error on the side of caution.

 

[chrisj]

It somewhat depends on your 6mm AI reamer...but unless you have an oddball reamer...it can be done. If you take a standard 243 case and a 6mm AI and run a caliper around each in the same spot, you will see that it is doable. Also look at the 2 reamer drawings. Been done many a time without cutting any bbl off. Rechambering to 6 AI from 243 AI may be a differnt thing.

 

[therifler]

chris trust me when i say there is a difference and you are not going to pick it up using a vernier cal. on two different barrels anywhere from 1/2" to 3/4" of the original chamber remains from the 243 win. i use PTG 6mmrem ackley reamer.win chamber is about .002 bigger but that is enough to make it tuff on the resizing die . i also build 6.5 X 250 ack.based on the 22-250 round i can not make this from 243 case because the last 1/2" is to big in diameter . if i sand the last 1/2 " of the 243 case down .003 thous.it works . however that just is not an option . mike www.therifler.com

 

[oldroper]

It somewhat depends on your 6mm AI reamer...but unless you have an oddball reamer...it can be done. If you take a standard 243 case and a 6mm AI and run a caliper around each in the same spot, you will see that it is doable. Also look at the 2 reamer drawings. Been done many a time without cutting any bbl off. Rechambering to 6 AI from 243 AI may be a differnt thing.

They are different if you measure from the rear of the rim to start of the case body the 6rem is appr .002" longer than the 243 case. I would want to set the barrel back and having the factory marking etc under that barrel and only looking at 6RemAI marked would be better to me.

I'm a big fan of the 6RemAI got two of them just had a 243AI build last yeart nice caliber.

 

[North Fork]

I would shoot it as it is. Then when the barrel is worn out then i would make it into a 243ackly.because you can get lapua brass for the 243 ackly but not 6mm ackly.

 

[CJ6]

Leave as is for now. If it's shooting to your accurracey requirements now, learn the drops and deflections. Then when the barrel is shot out go to the 243 AI. Now there's nothing wrong with the 6mmAI but it works better in a long action for magazine use with the heavier bullets