simple, short, and sweet as the subject title goes: did any USMC (or other service) M16A4s that came with long ribbed A2-style handguards ever have an ACOG equipped on the flattop, or a Grippod Systems foregrip attached to the handguard?

or, were Grippods and ACOGs seen only on M16A4s that had KAC RAS drop-in handguards?

Yes, second echelon troops generally.

I was in the Corps 05-09, Iraq twice. We had 16a4 and kac broomhandles in Spring 07 and grippods MK12s on 08-09 Deployment) , rear eschelon types had a2 or m4 for Staff/Ofc for forward or rear. Seeing an A3 (carry handle or optic, but a2 handguards) would be rare but sometimes Air Force would have them on bigger bases.

Sorry im having trouble following here...so front deployment troops such as yourself had 16A4s with full RAS handguards (& KAC brooms or grippods), but with flattops & ACOGs whereas the rear eschelons had 16A2s?

I presume then A3s as you laid out (flattops with A2 handguards) never would have had picatinny rail adaptors for the ribbed handguards to equip vertical foregrips, and seldom were seen with an optic as opposed to just a detachable A2 carry handle, but if their A3 did have an optic, it would have been like a TA31, no?

Follow-up then: were M7 bayonets issued to rear echelons or USAF personnel who would have had A3s?

Almost every imaginable combo has existed.

Short answer yes. I served with 2/3 Echo. I got to the unit in 2003.
During this phase, you could really see any combination because the A2 was being phased out for A4.

Depending on where we were, the Armories would draw out any combination. However I’ve never seen an Acog on an A2 carry handle.
Acogs were always on flattops. Sometimes rifles had rails, sometimes they didn’t.
It just depended on what that armory had on hand.

It’s not like you got issued one rifle once you got to the fleet and kept that rifle the entire time.

lol I remember wanting an A4 so bad because of how cool they looked. But plastic hand guards are easier to keep clean and when ounces equal pounds, shaving weight is a big deal.  So I didn’t mind the plastic hand guards too much.

That’s just my experience. I can’t speak for others.

So you can vouch for an ACOG having been on a flat-top A4 but with A2 round plastic handguards, not an M5 RAS?

I'm getting so hung up over this because whenever you fire an internet search for an 'M16A4', you get a 20" A2 flattop upper with a detachable CH on an A2 lower OR an ACOG on a flattop upper with either a drop-in KAC, but never the optic on a round handguarded upper...neurotic complaint perhaps, but just I wanted to get closure on that...