Recieving a 4 1/8" threaded barrel so I can suppress my STEN what

[m1garand_man]

I ordered a 4 1/8" barrel to be made my SA machine so that I could put my AAC EVO9 suppressor on my MKII and have it look like a pseudo MKIIs. I was wondering however what kind of rate of fire jump I might experience with the suppressor and short barrel also about how this mod might effect reliability. I was told by Scott that it might not run well unsuppressed with that short a barrel but I wasn't too worried about that. I was many concerned that a higher ROF would increase the number of malfunctions.

 

Any ideas on this?