If you are using pellets, you aren't getting the true 50 grains per pellet anyway. They like to claim its a 50 grain pellet but more like 46 or so.
The gentleman before had it right, overcharging the gun. and I know what you are saying about eyesight. Try shooting and being blind in one eye, but I shoot just the same. Living in MA allows one to shoot everything within 60 yards, unless hunting on the power lines and open sights are far faster than a scope anyday. That's not saying that my High power rifles aren't scoped, because they all are, but my in line isn't nor the side hammers, because I shoot traditional except if the weather is foul then the inline comes out. that one always goes off, no sweat!
45-70