It really depends on where you want the sling attached. The slots in the stock can accommodate a nylon piece for a 2 or 3 point sling attachment. If you want to run a single point sling, you need to get a sling plate that attaches at the base of the gas tube, meaning you need to remove the stock to install.
The Tier One Tactical Operator
Tippmann Arms M4A1
KWA USP .45, KJW P226, KJW hi-cappa