[lurkingknight]

zero to a hold over... really the only way to deal with the p90's height over bore.


so take your dot and measure the height over bore.. say it's 4 inches... at 30 feet you want to aim at a point 4 inches over where you actually want to hit.

at 60 feet, it should still be 4 inches over where you want to hit. etc all the way to your max range.

true zero on a p90 will suck because that means the line of your sight will eventually have to converge with the path of the BB... which means if you shoot at something beyond that convergence, your BB will now fly OVER where your sight is zeroed to so it has a chance of riding up higher than you want. This is not a problem if you know your ranges well.. but if you rig it so the gun will always shoot whatever the difference your height over bore is from your sight, you'll always shoot that or drop it so all you need to figure is how much to lob a shot if you're shooting at a point where your flat flight starts to drop.