Yes I know this bug is old, and has been reported probably countless times before, but since the whole epic Gunner Update is coming I thought now might be a good time to share this:
Spiral Knights: Alchemer Range Bug
This gets extremely annoying, doesn't matter if it's LD or PvE. My suggestion would be to either fix the hit registration of alchemer shots so they actually hit at longer ranges, or just reduce the distance they visibly travel so we don't have guns that look like they fire their shots at "X" distance but become defunct at said distance. 'Nuff said.