 FACT: When Street goes to blow the door open during the sewer scene  he uses the previously seen Claymore. However this would not have  worked as Claymores have a small amount of explosives in them and  would have very unlikely blown off the lock. Also to detonate the  Claymore he shoots it, this would not have made the explosives  inside explode as the explosive will have been C4 or SEMTEX which  doesnt explode when shot.