My experience lines up with Carl's, with the exception of the hyper-velocity ammo. There seems to be enough powder to use a couple more inches. I can't see any advantage going over about 20" regardless, and even at that point, you are probably making the rifle too heavy for what it is, unless it is for some sort of formal competition. One of the great things about the 22 is the light little guns it allows.
My 14 inch barrel has muzzle flash with all standard rounds of 22,more with 32 grain hyper velocity rounds ,
though little or no muzzle flash with TARGET/Standard velocity and subsonic ammo.
The 10 inch has flash with all of the above ammo and a good bit more with the hyper velocity ammo.
These are single shot (no cylinder gap,no slide motion relieving pressure) and that's about all the attention I ever paid to the subject besides the tiny groups downrange...minute of squirrel accuracy is pretty good for me.
Tip for shooters . The AGUILA 60 grain 22 ammo is ,at 50 yards,a 900 feet per second SLEDGE HAMMER. I don't feel
under gunned with my tiny Walther TPH and this ammo..over 100 foot pounds of energy (compare to 32 acp/just behind 380)
