Did up an M16A2 M203 clone and I really like the goofy classic look. Having some trouble though with a handguard that moves a little too much... It's probably only a couple degrees but, with the short sight radius between the front sight post and the ladder, it has a considerable effect on the POA. I'm entertaining using a quadrant instead or just doing up an M16A4 but I'd really like to preserve this classic look if possible. Any good way to eliminate rotation in the handguard? Handguard is LMT sitting in a Windham A2 upper.

Not to be a smart ass but, looking at the picture you posted the top of the delta ring is not fully seated forward.

If there is slop between the barrel nut/handguard/delta ring there will be movement.  It should be even all the way around.

Joat

That's certainly a good thought - entertaining anything at this point! The ring is canted because the plastic is only on the top half of the barrel nut vs handguards that use the entirety of it. I suppose I could pound it forward with a rubber mallet to really seat it! I wonder if that would stick after some bouts of recoil?

I have one of the carbine handguards and when I first installed it I didn't get the barrel nut exactly lined up with the indents in the guard, so it rocked and the delta ring didn't fully close.

Oh dang! I'll take a look - I wonder if that's it!