Hi ya
Have a look on the Jackals-Lair website ~ http://jackals-lair.com/aa_models_16.html it gives you the dimensions of the rifle.
Picture below is a picture I done giving info the Autoload system
you was able to buy the Auto Load System separately and put this onto any of the Models. I have a spare one in my bits & bobs and could actually turn my AR7 or Combat into one. Just never got round to doing it
Hope that helps
Paddy