Though I don't ever recommend or suggest reusing BB's (other than with grenades), with your FPS that low, you might get away with it. ie. the impact force is so low that it's less likely to put cracks or deform a BB, but it doesn't mean it can't happen.
What kind of trap, what AEP and what kind of BB's are you using? Makes a bit of a difference here.
If it's a cardboard trap with crap BB's, then it's not going to do much worse than the crap BB's you started with. Look at the BB's and see if you notice any seams. Roll them on a flat surface and see how round they really are. If the AEP is a low end pistol, then chances are you're not loosing much running crap BB's through the hopup (if it has one) or the barrel.