uhmm sorry the bolt should be longer than it is - so that it should fully cover the 'hopper' port when it is in 'raised' position (but I suppose that you've already figured that out)
The airram that operates the bolt is very awkwardly placed...
It's just a quick sketchup so it's placed there for simplicity sake... if or when I build it the bolt will be moved up and down using a spring and brake wire attached to an air ram or even pulled manually when used on a repeater
a very good hopper system
well I've been using a hopper for some time with my semi and their biggest drawback is the fact that they obscure sights making aiming difficult and that they shift the centre of mass up... this design is aiming at solving both of these problems
don't you think that is a good idea to make diagrams using google sketchup ? sure... it takes some time to get used to it but you can even download ready made models of various fittings and make animations etc.
don't you think it's a good idea to encourage people to use it ?