Well I've been talking with a friend of who is in rc stuff,I've been
researching large scale rc helicopters.I like the hueyII or the cobra,
and use wireless cameras to fly and aim.So for now I'm working
on the gun part first,as for firing,High speed gears,low fps and
medium turning barrels running off a worm gear set up.:)

An idea just popped into my head after posting.If these barrels are shorter,
I can shorten the mechbox because I don't need the full stroke of the
piston,Or so I have read in cylinder to barrel matching.What do you guys
think?.

With a light spring and high speed gears and motor,what kind of
ROF would I get before things got messed up,like the piston not
finishing its travel forward before the gear came around again and
throw off the timing?.