Hey Jim White, You're only a 100 fps slower then my Wby 257 shoots the 100gr bullet reloaded.

Hey jro45, If I want to load my Ackley to maximum pressure I don't lack anything as compared to a Weatherby. Jim

StoneCreek,

I agree that generally the improved versions do not add all that much horsepower. My .280 AI if I recall has an 8% addition in case capacity over the std .280 case. One Quarter of 8% is 2%. Two percent velocity increase is about all you can expect. The formula does seem to work. John Barsness and I have discussed this and he stands by the "formula" as well. Same with Paul Hart of Hart Rifle Barrels in upstate NY. He and his hunting buddies used to shoot quite a few Improved ctgs. For the small increase the improved version is generally not worth doing. Though the AI's DO seem to cut down your case trimming chores.

BUT........ If you read Johns Article ref the .257 AI in Handloader #199 he feels that the .257 AI does MUCH better than it SHOULD considering the 1/4 formula. He thinks it may be the relatively short yet fat case shape making it more efficient. Who knows? Interesting stuff to BS about though!

I SO wish I could have worked on the STANDARD version in this barrel, THEN rechamber to see just what the improvment came out to. In my .280 it truly did work out as the formula stated.

FN in MT

jro45,
My Speer #8 manual shows their test rifle going 3,410 fps with a 100gr. bullet. The barrel was only 22" long. FWIW the load was 57gr.Norma 205(I use MRP and exceed the above velocities)Remington cases, Rem 9 1/2 primers. I have been using the above load since the late seventies. Don't knock it until you've tried it.
Stepchild