October 30th, 2007, 13:19
|
#5
|
GBB Whisperer
Join Date: Jun 2002
Location: Toronto
|
The entire front end as well as the upper receiver is different between the standard M4 and the S-System.
It'd be easier to just pick up an SIR to install on your M4. Combine it with an A.R.M.S. Standalone flip up rear sight (or a replica), and you'll have a very close S-System replica that's built better.
|
|
|