Thanks for your reply buddy, don't get me wrong I like how it looks and how well built it is and also it's "different". I wanted something that was feasible for CQB and skirmish, my idea being I could switch the barrels (inner, outer + handguard) dependant on circumstance.
Your comment makes me think that it's a bad idea full stop. I'm a practical person that's why I want a shorter rifle for CQB. But I'd rather not wreck it, by slapping on something that's going to fit poorly
I'll keep this as my multi-purpose rifle and get a purpose built CQB rifle later