Hi all i bought a few bits from pellpax a Remington express .177 (asked to be changed to a .22) and a gamo p-900 pistol .177 i have only received half of my order up to now its been a few months but said they are waiting for stock?

Any ways my question is regarding the power of the air pistol it does not penetrate a tin can or a plastic bottle also if you fire it at wood instead of sticking into the wood it sends it right back at you? Is this normal for an air pistol and is it down to the power been 3.1ft/lbs?