Mp001 airsoft sniper question>>>?

ok i have a mp001 and bacicaly i have these parts for it but its a long story so anyways i have these part for a vsr 10 but this is a cheaper clone and the parts were for a vsr10 or jg bar 10 but anyways the parts are spring guide new piston renforced sear set and a spring the piston and spring guide dont fit in the cylinder but if i sanded them down to a fitting size would they fit and would they work for my gun?? thanks and also if i chronoed at a airsoft field and if my spring says its ment to shoot 400fps do you think they will let me play even if its a little bit over? thanks gabe