Remington R25

I have a .308 Remington R25, looking to replace the stock free float handguard with a DPMS LRT-SASS handguard. Does anyone know of any compatibility issues? Or does anyone else have any recommendations on a free float replacement?

Looks like both are DPMS LR308 patterns so shouldn't be any compatibility issues. Personally, unless you just need a quad rail, I'd get one of the newer KeyMod rail. Much cleaner and lighter platform.

This is a 15" CMMG RKM15 MK3 rail on mine. It is cheaper than the SASS quad rail as well. No special tools except a 1 1/2" spanner wrench.

May be a stupid question but how does that work with the barrel nut?

You'll have to change the barrel nut when you change the rail. You basically put the upper in a vice and install the barrel with the barrel nut over it and torque it to spec. Then you slide the rail over the barrel nut (tight fit) light the two top rails up with each other and tighten the two set screws under the rail which clamps the rail to the barrel nut. I run these on all my guns and have never had a problem with them coming loose.