I'm running a .25-06 AI on a 1in10 Hart barrel with a tight neck chamber. One thing I would never do again is to make one with a tight neck. Real PITA to have to turn everything prior to fire forming. Gun IS very accurate though with just about anything I put down the tube. Actually the gun is a way better shooter than I will ever be. But with all that said I do have to admit it has taught me more about shooting and reloading than I ever thought I would know or needed to know.
I also am a speed freak to a certain degree. And a lover of the .25-06 of which I have owned in my lifetime at least 7 of them and 5 at one time. First one was a custom built one prior to Remington even coming out with their version. It also taught me to reload. Second one was one of the first rifles that Remington built in .25-06 which I shot so much I just plain wore out the barrel.
With all that history though I found one thing. I could push the .25-06 as hard as I could but always came up wanting just a few more FPS and just a bit flatter trajectory. Made my first 700 yd kill with that Remington at 700 yds and became hooked on long range.
Since I finally bit the bullet so to speak and went to the .25-06AI I have been very pleased as I seem to be running less pressure and getting just a bit more out of my loads. Trying different powders and bullets I find I am even more enamored with the caliber but I'm still wanting just a bit more. My search for a new powder that would give it to me took me away from IMR4831 to H4831SC to a Retumbo loading which is very accurate but still lacking and I'm now looking into IMR 7828 which could prove to be the powder I"m looking for which if it works might just get me that trajectory I'm looking for.
Now with all that boring rhetoric I will say this. Don't ever fell bad about building a rifle in .25-06AI as it is an awesome cartridge and though it might be just a bit of a barrel burner 1500 rounds does not seem out of reach and could prove to be one of the best Antelope/Deer cartridges of all time (my opinion