Fix frag

Fixes #10006 
While testing that fix, I noticed shrapnel one-shots pretty much everything with a direct hit, including tankbots.  This happens because the damage range was 20-60, most of which range beats any armor in the game by a wide margin, meaning with a direct hit the monster takes ~20 hits doing an average of 15+ damage, which is way too much for shrapnel, so I toned down shrapnel damage too.  This is also good news for heavily-armored players engaging a tankbot, the 40mm bursts should be survivable with minimal damage if you have high cut armor.