I haven't shot a NRA HP match since the GW Bush administration, but I just found out that you can use optics on service rifles now, and I think I'd like to give that a shot at my local club.

My question is, what free float AR15 handguards are legal for service rifles? The NRA 2019 book says "quad rails or similar", and the CMP book says "The rail must have a continuous Picatinny rail section on the 12 o’clock position that does not exceed the height of the receiver. The rail must have Picatinny rail sections at the 3, 6 and 9 o’clock positions for a minimum of half the length of the handguard."

I have an Aero Precision Atlas S-One on my 20" Bergara upper, is that legal?

Thanks!

Still use my WOA, service upper.
See KAC rails,,and these.
WOA uses these as well

https://geissele.com/super-modular-rail-mk7-national-match.html

The CMP rule has changed for 2020,

Handguard. The receiver and handguard must be machined as separate parts. Standard M16-type service handguards (which may conceal a float tube) may be used or military design or aftermarket free floating rail systems may be used. The rail may be of one or multiple piece design and be attached to the receiver by means of the rail itself or with a standard or special barrel nut. Key-Mod, M-Lok or similar mounting systems are permitted. Handguards may be of any length and the front sling swivel may be attached to the hand guard, but any front sling swivel location must be fixed 13 in. (+/- 0.5 in.) from the forward edge of the magazine well on M16 configured rifles or 8.0 in. (+/- 0.5 in.) on M4 configured rifles. Handguards or float tubes may not have any additional features that could be used as a hand stop.

2020 Rule book

The aero would be legal now, but wasn’t last year. 🤷🏻‍♂️ Also you have to remember the sling tension and pick a rail that is sturdy enough for it. The easy button is find the old Armalite full quad rail, great prices and easy to install and remove, copy of the KAC, or find a Gisselle mk4 on sale, it is stiff enough for sling use. Or go full NM and add weights etc. all that said after having all these rails myself, I use the old RockRiver float tube with full weight and A2 handguards, as do most. For this type of event it’s hard to beat.

Excellent, just what I wanted to know.

I'll probably shoot a few this year with the Aero handguards and see if it's my jam. If so, and if the Aero is too bendy,  I think that Geissele rail would be the ticket.

Thanks!