What would you build? For varmit hunting and Deer also? Just kicking the idea around, what are your thoughts on these calibers?

FWIW, I have never been a fan of improved rounds because I have never seen the return for the amount of extra work invested. I'd go with the 25-06 and never look back. If you want more poop from the calibers listed, I'd go with the 240 WBy or 257 WBY. Lou

On this I agree very much with Dr Lou. I've played with and tested many AIs and other improved versions over the last 30 years. The AI gain in a 243 is marginal at best at equal pressure. Most gain in the 243 is pressure related compared to the factory 243 loaded at 60,000. In the 25-06 at equal pressure you might see 50fps from an AI.

I built my own 250PDK (think a 25 gibbs with 3 more grains) All I did was burn several grains more powder to get 45-50fps. I pulled the barrel and went back to 25-06.

Either will work fine in std form. More varmints go 243 more deer hunting go 25-06.

If you really want an AI go for it. I own far more improved and blown out cases than factory. But an AI will for sure not make a 25-06 equal a 257Wby.

I'm a big fan of the Ackley in fact like the 6RemAI so much that I got two of them but I also shot a plain jane 6Rem. You would normal see appr 8% to 10% increase in velocity over a standard caliber using appr 10% more powder. I've never owned a 25-06AI so cann't comment on that caliber but one of my 6RemAI is set as my antelope rifle and I use 95gr Noslers the other I just got the barrel broke in and haven't done much shooting with it.
I've looked at doing a 25-06AI since Nosler is making 280AI brass be easy to neck down and use those cases. The only thing that has stopped me is bullet selection when I look at what available for the 6mm.
http://www.6mmbr.com/gunweek042.html
http://www.6mmbr.com/gunweek024.html
http://www.6mmbr.com/gunweek021.html
Well good luck

Sorry I wasn't paying attention. The 6mm is one of the better rounds to perform an AI on if you want one. Due to the taper you get a bigger gain than with the 243 or even the 06 based case.

quote:

Originally posted by Dr. Lou:
FWIW, I have never been a fan of improved rounds because I have never seen the return for the amount of extra work invested.

I've seen about 150-200 FPS on the same barrel since I went to the .25-06 AI. I get 3550-3600 out of the 100 grainers (both BTs and TSX) and 3250-3300 out of the 115 BST. The .25-06 AI is more than enough gun for anything under about 500 pounds. I also like the 6mm Rem... but have no experience with it in the AI format. The one negitive on the 6mm is always magazine length... I can't seat any bullets within .075" of the lands and still fit them in the magazine. Fortunately, mine is super accurate without having to seat close to the lands. If your primary quary is coyotes up to Big Deer/Caribou/Sheep... then you can't go wrong with the .25-06AI. If it's primarily a varmint gun with occasional shots at Deer... then I'd go with the standard 6mm. ~JT

I wonder why you bypassed the .257 roberts improved ? It is very close the the 25,06 but easier on barrels.
You probably know its the same case as the 6mm.
DDP mentions somthing I hear alot , about magazine length.
But with a 6mm or a Roberts a short action will work fine if you have the chamber and throat cut properly.
I took a couple dummy rounds that are loaded very close to the lands in my long action ruger
and they fit just fine in a short action rem or a short action ruger...tj3006

Ackley didn't recommend the 25-06 AI, and I agree with him. I have one, and it's hell on barrels with marginal improvement over the 25-06 standard - which is already overbore as well. I'd suggest the .257 AI, which is just about the right bore for .25 caliber. The 6mm-06 AI would be worse.