Well, the bullet drop compensation on ACOGs are made for the .223 fired out of the AR/m16/m4 platform. There are different ACOGs for each platform, and also for different barrel lengths and the grains of bullets you are using. Doesn't mean you can't mount them on a shotgun, it just won't do you much good. They are very expensive and quite a jump from the "cheap" red dot you are thinking about. They come in at no less than $1000. I've said this many times before, you should not waste your money on a cheap red dot, especially when you are wanting to use it on 12 gauge. Those cheap red dots that you see are made more for .22 caliber rifles or any calibers in that range. If you are going to get a red dot, I would recommend paying at least $150 for one, but the reliable ones come in at around $200+.. IMO if your going to make an investment on a red dot, just get an eotech holo. They are proven sights and should not fail with a shotgun. With a cheap red dot, you will almost certainly lose your zero after firing a few 12 gauge shells, whether it is low brass #8 dove loads or 3 inch magnum slugs. Also, many of those cheap red dots will lose zero when changing the reticle, and don't expect the glass or internals to withstand the recoil of a 12 gauge passed your first outing. Most likely the glass will just shatter, and/or the internals will be destroyed(especially with slugs.)
Last edited by Devin459; 03-08-2010 at 22:56..