Pumpgun Print in Place

This is a model of a shotgun / pumpgun I've designed. 

You should be able to rack the slide, when printed in full size. Sadly my printer hasn't a print bed large enough to test it. 
I've also tried to downsize the model to 40% while adjusting the tolerances. But my printer seems to be way out of tune, and it doesn't work. 

This is meant to be a toy. Please don't modify it in any way that could make it a weapon.