get your money back if that was me i would demand my money back like davy said just because its second hand it should still be working good i've had the same problem with a bsa scorpion i brought last year and it was well under power and when i took the stock of it it was well rusty wasn't a happy man. They tried to sort it for me and get rid of the rust but i just said i want my money back. And waited a few months and then brought brand new.You won't expected this from a gun smiths just be careful next time atb