Anyone using a 50mm scope on a Kimber Montana?

It seems pretty silly to spend a lot of money to get a lightweight rifle and then saddle it with a big heavy scope. If you have lighter rings and bases, use them.

Besides, any advantage the 50mm scope will give you would only be apparent at 10x and how often are you going to use that in the woods?

Why is this so? Because of a thing called exit pupil. Exit pupil is the ratio of the objective lens to magnification. The bigger the exit pupil, the brighter the image, HOWEVER there is a limit imposed by your eye. No matter how big the exit pupil of your scope is, you won't get any advantage over the maximum diameter of the pupil in your eye. For most adults that's about 5mm. (it can be a bit bigger for the young).

I don't know how much magnification you use in the woods, but lets say it's 4x. With the 36mm scope that results in an exit pupil of 9mm.(36mm/4) With the 50mm it's a whopping 12.5mm. Clearly the 50mm scope is brighter! No, because there's no way your eye is going to open up to 9mm, much less 12.5mm, so there will be no visible difference in brightness because anything over 5-6mm is wasted.

The 2-7x36 scope you already have is pretty much ideal for your Montana, keep it, put on some lightweight rings and bases and enjoy.

As Natman said there is no real gain in performance that the human eye can use. The extra light is mostly wasted and you end up with a heavier scope that must be mounted higher to clear the barrel

Only at 8X or 9X you will see a very slight increase in light. On 10X a 50mm scope lets in exactly the same amount of light as a 40mm scope on 8X. On 7X or less both scopes let in more light than the human eye can process. It is there, but wasted.

But since you already have it, it is worth a try. You may like a little added weight. I used to use a Leupold 2.5-8X36 on my Kimber 308. I had an older 3-9X36 Zeiss Diavari setting around unused that I decided to put it on. It is almost exactly the same size, but 5 oz heavier. The weight of my Kimber went from 5 lbs 15 oz up to 6 lbs 4 oz. It is still light, but I found it easier to shoot with just a tad more weight.

Give it a shot. You might be able to mount it in the rings you're using now, to try it out.
There's a big advantage early and late in the day with the bigger objective.

For one season, I used a Nitrex 3-10X50 on a 20" barreled Remington SA ADL. It handled a little differently, but was no problem at all. I pretty much forgot about it while I was hunting.

R H Clark said:

I understand exit pupil, and as explained I won't be adding weight. It's right 6lbs now and would remain the same within a half ounce or so. I am not going to quibble about a half ounce. I'm not talking about putting a 24 oz scope on it.

I just wanted some opinions from anyone who is using a 50mm as to how it handles.

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I understand that the net weight of the 36mm scope with steel rings/bases is similar to the 50mm scope with light rings/bases. How about the 36mm scope with the light rings/bases?

What do you see as a potential advantage with the 50mm scope? Do you need more than 7x in the woods? If you understand exit pupil then you know it won't be any brighter.

I don't have a Kimber Montana or a Kahles scope. The attached is my Sako 85M Stainless Synthetic with a 50mm Zeiss Conquest 3.5-10X50 on it. I find the scope a bit big but you can hunt until shooting light is gone. The Conquest scope will put you into some ethical dilemma's at times.

Good luck and shoot straight.

Bob