Someone recommended chrome plating the bolt components to improve reliability in the AR - any of you guys tried hard chrome, and if so, did you notice any benefit ?

I think it matters on the inside of the bolt carrier, not the outside. In fact, I read that chrome plating the outside is bad.

as I understand it hard chromed bolt/carriers are preferred because they are much easier to clean.

The surface will not absorb grime like non-chromed parts do.

It makes sense to me.

Les Baer, LMT,  and others have 'em

The important part of your carrier is already chromed; the imside wall where the bolt rings ride, and the inside of the carrier key. Anything else is pure ego puffery.

Easier to clean? Give me a break. What they really mean is that you have to clean it because the residue on a chromed carrier shows up more and looks worse than on a parked bolt/carrier assy.

I've had a chrome carrier, that I picked up in a trade. Swapped it for a Colt standard parked piece.

I do still have one chromed piece; a very early Colt smoothside unit that lives in the early M16 clone I built up; but it's there for authenticity, not function.