I have considerable (though dated) experience with AR type rifles (M16 Viet Nam 1969). However, not so much with the current trend AR's. O.K., I'm old but I'm building my first current era AR.
My question - is the collapsible carbine stock buffer spring length the same as the rifle length spring. I know the buffers are shorter and will probably use an H or H1, just not sure about the spring