I always thought FP-10 was used to lube pellets for PCP shooting. I thought before there was a concern about it degrading seals, but maybe they changed the formula. The problem with spring guns is they develop high enough temperatures to ignite just about any lubricant, even hi tech synthetic ones. I have used the RWS spring (very sparingly 1 or 2 drops!) lube before and it seems to work. You can add it through the slot in the receiver directly to the spring. This stuff will diesel so be don't add too much!