don't know about the rails for that model but on my sig556 er the troy rails that i have allow you to remove the gas tube without removing the rails.which i like even though you do not have to remove the gas tube to clean it it to me is better in that respect.i like it i can remove it without taking off the rails.i would call and ask if it is an issue for you but other than that it is whichever you like the looks of better. also i bought the troy rear dioptic sight and front hk folder from them with tritium and i love them. Troy also has a cool zombie killer game on thier site when im bored i play it it is cool.