Terminal effects of a rubber "bullet" on a deer would be interesting..the equivalent of giving the animal a good slapping! However, as I said in my initial thread, the rubber is most useful for use in the cabinet or transporting the gun ..not for field use, but if we carry out our pre-stalk checks there is no reason to forget to remove it, and as I ALWAYS use the 308 or 243 with mods. I thinkI would notice it! Cheers!.