Barrel length isnt an issue its the same length as my sig. Tightbore doesnt help with accuracy best size to go for would be 6.05 or 6.08. You have too much pressure on the right side of your hop which is why its curving right. Your fps is fine for cqb even outdoors isnt an issue. I use a firefly bucking and prommy or firefly flat nub with a PDI 6.05 in my sig it works a treat.