My thinking is that even though the ammo may not be called subsonic it might still end up being subsonic because of the shorter barrels. 1. Will standard velocity ammo be subsonic out of a 4" bbl? What about 5.5"? 2. Will high velocity ammo be subsonic out of a 4" bbl? What about 5.5"? 3. Is there any other reason to go with one over the other? 90% of the ammo around me is high velocity and so is 100% of my stockpile. (Federal 550 Value Pack 36gr copper plated HP High Velocity) If I can use that ammo with good results I would prefer to do so. I can occasionally find standard velocity. I know I can buy whatever on the internet but would prefer not to. Thanks in advance for the help.