I might be mistaken, but I believe most of the 26" barreled guns are the .45cal models. Even so, I tend to doubt that the extra 2 inches are worth the bucks to move up to a 26" model. Like you said, you're not looking at taking 200 - 300yd shots, so why spend your scope (or powder) money for the extra 2". One thing about muzzleloading, it don't matter if you put a 50" barrel on it & load it with 300gr of powder - it's still a muzzleloader with its inherent deficiencies when compared to a cartridge rifle.

I'm really happy with the USAK - it is a great 1st gun to learn MZloading with. I'm likely to upgrade to a higher model at some point - though when a gun does everything you tell it to do, it's hard to just replace it for the sake of "new & improved".