Hello.
Changing front sights on my DG guns has been like blowing the candles on the birthday cake every decade or so. I had to get from a 5/64" bead to a 3/32" as a 40th birthday "gift," then to a 5/32" for my 50th candle, and as I will blow the 60th in a few months, I reckon that I would need a 1/4" bead by now LOL. Yep, I can still shoot the 5/32" in a bit of a blur, but I will only group 2 to 3 " with it, so, let's face it, my iron sights days are gone.
I am sticking to a low power Schmidt & Bender 1.25-4x20 30 mm tube (an amazing piece of glass!) on my .416 Rigby because it can reach out to 200 yards/meters should an impassable opportunity arise on large plain game while tracking buf, but I do not want glass on my close range DG .458 Lott.
I have used an EoTech EXPS2 on a black gun for a while, which I did not turn back in with the recall program because I never had any problem with it, despite the fact that I live in Arizona and I am using it regularly in 100F+ temperature. Since I do not envision myself going from -20F to +120F in the course of one day, it does not bother me that I may need to re-sight it if I move from Arizona to Alaska. My kid has cycled through at least half a dozen Chinese $30 clones, and he broke them with such regular monotony after a few hundreds of rounds, that I stay away from them (and I ended up buying him a Vortex red dot out of sheer compassion).
So, based on my experience with two-eyes-open shooting with a quality holographic sight, I am installing a Docter III 3.5 MOA on my .458 Lott. It took me a while to find the right detachable mount for the 12 mm dovetail of my Mauser 66 (the telescopic action predecessor to and the inspiration for the Blaser) but it is on its way as we speak from optics-trade.eu. They offer virtually any mount solution you could dream of. I selected the Docter based on the fact that if Heym, Mauser, Blaser, Krieghoff, etc. offer it as a factory option on their guns, it has to be of compatible quality.
Will tell you how it works, but based on my experience with the EoTech, I expect that it will get the .458 Lott back in a 1" group or less (amazing actually how accurate these big guns can be once you understand how to live with the recoil).
Thx
Pascal