I have three SP-10's, and of the three, two of them have the shorter barrels (24" maybe) and one has a 28" barrel..... using TSS 7's and an indian creek .690, the pattern on the longer barrel is ridiculously tighter than the shorter one (i have only shot one of the shorter barreled guns)... same choke, same shells, way different pattern.... i couldn't see the barrel being longer making that extreme of a difference, but I could be wrong.... I just don't know why exactly i am... my question is this: Is the forcing cone of the longer barrel a little bit longer than the shorter barrel? both barrels of course are the same on each end, but have different taper per inch due to the length... could the forcing cone be longer increasing the performance of the longer barrel? could it be due to the increased muzzle velocity of the longer barrel? or is it just better because its got 4 more inches of barrel? ALSO, those who have the shorter barrel guns, what constriction choke do you use? TIA