Not familiar with the 10i. My M4 lower has a rear attach point on the butt stock, and my Tac upper has threaded holes in the lower picatinney rail. I found that 10x32 swivel screws thread right in. Maybe yours has them also? I usually keep a Harris bipod attached and those have an attach point for a sling. You can find adapters that fit on the Pic rails for most anything. At times I've used an M4 single point sling, but the Tac15
is a little heavy for a long walk using that method.