I have a Glock G40 10mm MOS on the way. I am pretty sure I will put a 3MOA Burris Fast Fire 3 on it.

The factory MOS Glocks come with normal iron sights that will be unusable/hidden by the Red dot.

Should I spend the money to get tall iron sights from dawson (or others) that will co-witness in the field of view with the red dot?
Example of tall co-witness sight sets

The use of this gun is for range shooting(targets/steel) /field shooting and possibly I might try hunting with it.

I already have a G23 for CCW/Home defense.

The real reason I ask is not for a backup if the red dot fails (I will just take it off and use the normal sights), but some have mentioned that the co-witnessed iron sights help you "find" the red dot.

Opinions and experience appreciated.

Thank You

Yes. Cowitnessed sights help out tremendously, especially on the draw and/or first shot. With cowitnessed sights, you just get your sight picture like you normally would and the dot just appears on the tip of your front sight.



I use Ameriglo suppressor height sights with my current RMR'd pistols, and I just ordered another pre-milled slide that will be arriving with the OST "RMR Optimized" sights to try out. I'm not sure if you need something MOS specific, though, as I know the RMR doesn't sit as deep in the slide on the MOS platform as it does in an RMR specific slide.

No need for co-witness sights. Just train and through repetition, you should be able to bring the gun up and be in line with the optic.