Why shoot ai calibers?

[JRS]

I think a 260 AI is the best choice for shooting a 6.5 caliber. One better is a WSSM
Then the cases are junk . Larry

That will change once Lapua Creedmoor brass is available

 

[22BRGUY]

That will change once Lapua Creedmoor brass is available

Might have something there if it comes with small rifle primer pockets and then can be AI'd

 

[Joe R]

Stay bald! All that money you save on hair care products can be put into bullets, powder, primers and brass. That's what I tell myself, anyway . . . .

In my case I find myself spending more money on hats then I do on haircuts. Are we off topic now?

Joe

 

[JRS]

Might have something there if it comes with small rifle primer pockets and then can be AI'd

It is being manufactured with the small primer pocket and small flash hole. I don't know how you could improve on the design of the case. It is essentially a 6.5x47L improved plus.

Edit: Actually, necking it down to 25 caliber would be an improvement. The 25 Creed

 

[savagedasher]

In my case I find myself spending more money on hats then I do on haircuts. Are we off topic now?

Joe

Never would happen here !!!! Smile Larry

 

[XTR]

If we are talking about 308 based cases I personally don't think it's worth it. There is what, something like .004 total taper on a 308 based case. You get very little volume increase. Now if you are trying to wring a little more out of a 7-08 or a 260 for an F class application I might see it.

One thing I'd be very wary of is the velocity claims found on the WWW. Most reliable sources will tell you that you gain about 150FPS going from a 308 to a 30-06. That is a gain of about 12 grains of H2O capacity. I think an AI version of the based 308 case gains about 3 grains or so of H2O capacity, so I am somewhat questioning of the purported velocity increases of the AI versions over what a hand loader can get with the parent case.

For other applications, I'd be more inclined to go the opposite direction with a 6mm or a 6.5mm and make an SLR (which I did for my 6) to get the 30* shoulder. You lose about 1.5 grains of capacity, get a longer neck and a better shoulder, but again, that's personal and what another person does it all their choice.

When PO Ackley started playing with his improved concept cases in general had much greater taper. Look at a 30-40 Krag (30US) case. It goes from roughly a 308 capacity to about a 30-06. Or the 30-30. Another case that can see pretty big performance benefits in the AI variant.

 

[USMCDOC]

I am a big fan of the .240NMC.. always have been.. Not quite AI, but it is an improved case with a tad more boiler room over the 6XC.

 

[Rust]

Parker Otto Ackely. His books should be required reading and I regret he never got around to Volume III. He pretty much paved the way for modern case design along with Warren Page and Phil Sharpe. Unfortunately it is nearly impossible to mass produce cases with a 40 degree shoulder, well there is the .416 Rigby but those are expensive and big. The 6.5 X 284 has a nice shoulder at 35 degrees.

To me the primary advantage to a AI case is reaching the maximum velocity of the parent case with less pressure, and to a lesser degree reaching a higher velocity at the same pressure. Probably the best example of this is the .250 Savage which with lighter bullets meets 257 Roberts velocity and sneaks up on a 25-06. Oh, and any X 57 case such as the Roberts responds very well to improvement. I think a 6.5 X 57 AI would be a very good case hitting 2950 with a 140 gr VLD with less pressure than a .260 AI and having a lot more neck which IMO would be a good thing helping to save the throat of the barrel.

I have a 22-250 AI which is an absolute tack driver with near bench rest accuracy which I don't shoot a lot unless there is an especially annoying varmint about, and a 6mm AI that didn't work out as well, wrong twist marginally stable with 105s. Maybe that will turn into a 6.5 X 57 AI with 130s.

Still, trimming cases isn't all that big a deal with a Wilson micrometer case trimmer and powered screwdriver. Not a super high volume shooter for the main part.

 

[Clark]

I was getting great accuracy with 257 Roberts Ackley in 2002.
Since then I have been doing about that well with 223, and better with 6mmBR.

6mmBR is my best cartridge for accuracy.

Not as well as 257RAI with; 6mmRem, 25-20, 260 Sav, 25-06, 260, 6.5x55, 6.5-06, 270, 7x57m 7mmRM, 30-30, 303B, 303S, 308, 30-06, 300WM, 8x57mm, 338WM, 35W, 44mag, and 45 Colt in rifles at 100 yards.

I am going to try a 250 Krag ackley reamer and dies I have in 2017.

 

[Mark Walker in TX]

To me the primary advantage to a AI case is reaching the maximum velocity of the parent case with less pressure....

;-)

 

[XTR]

A long time ago I started pondering the idea of a highwall in a 30-40KragAI necked to 7mm. Not sure what to call it... 280rimmed? )

Some day, but if I do it I'll have to teach at least one of my sons to reload for it because nobody will have a f'n clue what it is when I die.

 

[rifleman700]

If we are talking about 308 based cases I personally don't think it's worth it. There is what, something like .004 total taper on a 308 based case. You get very little volume increase. Now if you are trying to wring a little more out of a 7-08 or a 260 for an F class application I might see it.

One thing I'd be very wary of is the velocity claims found on the WWW. Most reliable sources will tell you that you gain about 150FPS going from a 308 to a 30-06. That is a gain of about 12 grains of H2O capacity. I think an AI version of the based 308 case gains about 3 grains or so of H2O capacity, so I am somewhat questioning of the purported velocity increases of the AI versions over what a hand loader can get with the parent case.

For other applications, I'd be more inclined to go the opposite direction with a 6mm or a 6.5mm and make an SLR (which I did for my 6) to get the 30* shoulder. You lose about 1.5 grains of capacity, get a longer neck and a better shoulder, but again, that's personal and what another person does it all their choice.

When PO Ackley started playing with his improved concept cases in general had much greater taper. Look at a 30-40 Krag (30US) case. It goes from roughly a 308 capacity to about a 30-06. Or the 30-30. Another case that can see pretty big performance benefits in the AI variant.

A longer neck is always a good thing and is often overlooked.

 

[centershot]

A longer neck is always a good thing and is often overlooked.

As in the .222 Remington?

 

[Barlow]

I have a Ruger 77 ts chambered in 257AI. It was always accurate with 100 gr and lighter bullets but erratic with 115's and 120's. My new Rock Creek 1 in 9 should fix that problem. Should be fun this spring load testing. When you read the Ackley handbooks you will find he was brutally honest on the performance of his designs. If one did not measure up he would tell you it's a waste of time. Barlow

 

[Ggmac]

XTR , they ( those that came before us ) already have the 6,7, and 22 /40 krag Ackley . It's a good but brass is getting hard to get . I have a 8 or 32 /40 krag Ackley . I've since started using the 30-30 win as a base cartridge . Velocity is within 50-100 FPS of the krag based .
PTG just had a sale on a 6-40 krag reamer , I was tempted but couldn't justify another .

 

[Barlow]

Along the same line. Does anyone have a 30-40 Krag AI, and what velocities are you getting? Barlow

 

[Rustystud]

The 40 degree shoulder is better on some cartridges than others. The 280AI is a great cartridge as is the 6mm Remington AI.
Nat Lambeth