6mm AI - 243AI

[Calcoyote]

Would a 243AI or 6mmAI in a 22 inch bbl give any performance boost over the standard 243 that I am loading for now?

I like shooting bullet weights from 85-95 grains in this caliber.

[GaCop]

With the increased case capacity after fire forming, you should see a velocity increase. Hard to say how much. A chronograph will tell you what you want to know.

[savageboy]

Check 6mmbr.com, do a search, there is a good article- bottom line is West custom rifles owner who recently passed away, recommended the 6mmAI due to neck length, increased cartridge capacity, etc.

[Eric in NC]

The 243 case doesn't gain much capacity when you AI it. But the 6mm gains a LOT. I would go with a longer barrel to maximize that. Of course you will gain "some" with the 22 inch tube but I you are set on the 22 inch length, I think the standard 243 is fine.

[Jamie]

AI either of them in a 22" barrel and you will gain velocity. Or just make it a 6mm-284 and velocity will never be an issue, even in a 22" barrel.

[Calcoyote]

Very interesting comments.

I mounted a factory take-off barrel onto my Savage 10 action a couple of years ago and love it, but trimming brass is my least favorite task of the reloading process. My understanding is that the brass does not stretch as bad on an AI chambering. Plus I love the idea of playing around with a wildcat (something I have never done).

[gotcha]

If you don't like trimming you'll love the AI's. On fire forming, the parent case will actually shrink in O.A.L. as it takes the shape of the improved chamber. My 100 rnds of match prepped 6mm AI brass has grown about .003" in five reloads each. This is neck sized 1st two reloads, F/L size 3rd. ............. F/L sized to move shoulder back .0015" to .002" ......... Collet die for NK sizing. Have fun w/ the decision :)

[bootsmcguire]

+1 with gotcha.

I am seeing similar results in my 243AI. Really cuts down on the trimming. Go with the Lee Collet die for neck sizing, I use a Lee Collet Die set and added a 243AI Body Die from Redding to bump back shoulders as needed. Works like a champ.

[gotcha]

Boots, Nice to meet a man of superior intellect ;D ..... My brass has yet to reach minimum trim length. And, yes, the combination of body die & Lee collet die is real inexpensive leaving jingle in the pocket for one of those nice micrometer seaters ;) In my case the body die works for both my 6MM AI & .257AI.......... Definitely qualifies for the cheap skate of the year award. I'm counting on your vote !

[bootsmcguire]

People say that I can make the most out of my money like my grandfather used to do. People have told me that my grandfather "Could pinch a penny so hard it would make Lincoln's eyes bleed."

I don't know if I am that much of a penny pincher, but the Collet Dies and the Body just seemed to be a great idea.

[GaCop]

Boots, Nice to meet a man of superior intellect ;D ..... My brass has yet to reach minimum trim length. And, yes, the combination of body die & Lee collet die is real inexpensive leaving jingle in the pocket for one of those nice micrometer seaters ;) In my case the body die works for both my 6MM AI & .257AI.......... Definitely qualifies for the cheap skate of the year award. I'm counting on your vote !


And you call me cheap........ ;D

[gotcha]

Cop, I didn't say you were cheap. I said you'd squeeze a nickel 'til the buffalo sXXt which makes cheap seem like extravagant. ;D

[GaCop]

Cop, I didn't say you were cheap. I said you'd squeeze a nickel 'til the buffalo sXXt which makes cheap seem like extravagant. ;D


Oh.......................ok, can't argue with you there.

[GaCop]

+1 with gotcha.

I am seeing similar results in my 243AI. Really cuts down on the trimming. Go with the Lee Collet die for neck sizing, I use a Lee Collet Die set and added a 243AI Body Die from Redding to bump back shoulders as needed. Works like a champ.

+2!

[Blue Avenger]

if your barrel is a .243, a 6mm AI will not clean out the old chamber. just a bit smaller dia.