You won't lose that purdy edge if you're wanting to bake normals. Check the lip below the slide release here, it's a floater on the LP but modeled in on the HP.
I did some tests and I'm getting a dark seam on the floater. I tried both snapping the float on the surface, and intersecting it a little, and the seam always remains. :(
I'mma give it to you straight. This is a good model that you've done. Well job'd! I'm enjoying the entirety of it except the m4 stock adapter piece. It looks blobby and lacks definition in it's shape as if you didn't have good references for it, #sorry. Mspaint is the shit, yo. The weakest part of this is the…