edfromnj wrote:"Don't mount on Gas Block" I believe has to do with height. I think the gas block and the continuous picatinny rail are at different heights.
I use Diamond Head sights. they are pricey, but I really love the way they line up the diamond and the square make for really fast acquisition.
I too use Diamondhead USA sights but as Ed said rather pricey.
Ed did bring up a good point. You can mount on a gas block so long as its design for the same plane (heights to match with your rear sight). For example, on mine, I didn't want to buy the correct front sight to mount on my gas block because I wanted the flexibility to use these rather expensive sights on other ARs I might get in the future which might have free float handguards. So I bought a spacer that brought it up to the right height. They work great and are Absolute Cowitnessed with my Vortex Strikefire.
The other reason why they might say not to mount on a gas block would be due to it being made of plastic vs polymer. There are two camps. Ones that think this is all bullshit and ones that swear they will melt. I think so long as you aren't doing mag dumps through your AR you should be fine with polymer on gas block. They are cheap compared to the for example my front sight flip up metal Diamondhead USA sights. So try it out.
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