djben9

scientific science based science research

Haha that's the wife's area, me, looking to see if it all possible with advice on here if I swap out my upper gear box on my M4, add a scope and 'silencer' and be able to sit back once in a while and pick people off while disguised as a bush in a pile of rubble

As it's an ICS then in theory yes, you could get a second upper box and fit it with a stronger spring and do as you suggest. The thing to be wary of is the restrictions on fire modes that most sites have for DMRs (semi only on 400fps+ for example).

Also - the motor and lower gearbox needs to be ok to pull the bigger spring properly.