elfman Wrote:Seekins MCSR V2. Slightly larger diameter, 1.8, but you can fit a SLR adjustable block under it. It will also cover most suppressors, if you go that route later.
With respect, the OP is wanting a handguard for a 20" barrel so won't be needing to enclose the suppressor with the guard. Even if he purchases an over-barrel/reflex design that comes back down the barrel they are never any longer than 4". I don't think anyone makes handguards longer than 16".
My choice would be SLR Rifleworks Solo range. All Solo's shorter than 15" are under $200. I prefer SLR because they are made from 7075 T6 aluminium. Almost all other brands of handguards including Seekins are made from 6065. 7075 imply they are stronger with less flex (all other things being equal, which they are not). Obviously the shorter you get the less it flexes too so up to you how much rail length you really need but I have no use for a rail longer than 12". If using a Solo then their set-screw adjustable block fits with clearance but I don't think their clamping model does.