Dave Smith, an unassuming firearm engineer signs up for a lucrative job, gets dumped in Equestria instead.

How far a pair of working hands and one semi-working head will get him? Nobody knows, but it's bound to get chaotic down the line.

Cautionary tale of why you don't leave your engineers unattended in parallel dimensions.

Note: I try to do fair bit of research to make sure that what I write is in line with laws of physics and such.
However, if you see a factual mistake, don't hesitate to tell me - I'll try and fix it, unless it's a deliberate artistic embellishment on my part.