[Nocturnal]

because you will be changing the length of the inner barrel you 'should' have the proper cylinder for the length with and without the barrel extention. otherwise in theory it does more harm than good like ert says.

do you really need that extra innerbarrel length? it would be better to have a pistol/sidearm for CQB and have your aeg setup for field use (mid range/long range)

this would be more cost efficent than to do the steps necessary to achieve the power flexability you are looking for. Something like the ICS M4s can do and the expensive SystemA PTWS can do without having to do much work.

though if you do achieve a successful setup with your idea thatll be great. good luck with your future endevours

*note* this is the same thing i've pondered in 2004 and realized that it was not worth the extra work just for airsoft.