or you mean max power? Lenght does not increase accuracy, a "good" 12" barrel will out group a crapy 25" barrel everytime. You may gain 10-15fps per inch (up to your power limit) but you wont inprove groups just adding lenght. How bad are your groups as is? Have you crowned it? Baffles clipping? Other? If your barrel really is bad a new crosman barrel is only around $25.00 and Greg had done a good number if tunes using stock mrod barrels which group great, look at everything else before you spend dollars on just a barrel if you have accuracy issues, you would hate to drop $150+ just to find out it was something else.
I personally have a 25" .22 HW barrel from Mac-1 on a Bam that shoots sub-moa at 100 yards, but that was the last thing I tried looking for good groups.
John
