9-ex is an excellent option - Samson Evolution 10in Series Handguard

This 9-EX is almost a 5 star product. It is excellent in that it is one of the only alloy rails you can purchase that will work with an Adams Arms gas piston system. The finish is standard anodizing. The design is very well made, and you can mount small picatinny rails just about anywhere, without having huge quad rails bulging all over the place. The fit is super tight, and doesn't move. The design allows you to use the original mil-spec barrel nut. When installed, it prevents your barrel nut from ever coming loose, by having anti-rotation tabs on the top rail.

The only gripe I have, is that the holes on the lower front that allow you to tighten the set screws on the gas block, need to be relieved just a little more to prevent scratching of the finish. The holes are just slightly off (a little high), thus your Allen wrench inserts at an angle, and makes it difficult to tighten the gas block screws.

Other than that, once it is installed, it is without a doubt the nicest hand guard I have on any of my rifles.
Pros: very light, tight fit
Cons: gas block access holes

This review was written in the old system and had content requirements that are different than reviews written today.