Well i ordered a Chronograph, and it hasnt came in yet for like 2 months! anyway, when i test my Gamo Delta, and if it is way under the fps it should be, what can i do to fix it?
my airguns, Crosman Quest 500, Gamo Delta, Daisy Buck, and Diana Mod 24!
If the velocity is below normal then you could install fresh power parts to bring it to new specs again. Spring, piston seal, and breech seal. There is also the chance that you rifle is starving for lubrication.