40mm Or 50mm Scope Lenses

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Ammo Smith
Mar 11, 2013
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I've always liked the 42mm-44mm scopes since I could use low rings and mounts.
Will I have to use a medium with a 50mm and is there a disadvantage/ advantage between the 40mm and 50mm lenses?
 
Rodger
It will depend on the action and barrel contour but most likely the answer is yes. I do not own any 50mm scopes, while they gather more light than the smaller diameter scopes. From a hunters view point I feel it’s better to have the scope lower to the bore, and stock. Too high means you may have to lift you head to get a full field of view. Just my 02 I am sure others will have a different perspective
 
You'll almost certainly need higher mounts. The larger objectives lenses are more popular in Europe...where they tend to shoot with their heads up off the stock and hunt in full dark.

Most Americans shoot with a cheek weld and seldom shoot in that low of light.

I just don't have any real love for that much scope on a hunting rifle.
 
I don’t think a 50mm does anything for you but add weight and the need for higher rings.
 
Like you I prefer 40-44mm and that is what I have always used and never had an issue early morning or late evening. My nightforce is 50mm and in addition to med ring height I also had to add a cheek rest to my stock to get a good cheek weld and eye position.
 
Thanks for all the replies.
44mm scope lens have always been the top end of my comfort zone for cheek weld so I'll pass on the 50mm.
 
I use almost all 50mm objective scopes. Your ring height is very dependent on the base height. Many bases are high enough that medium rings work fine. I have never had an issue with check weld and use all standard rifle stocks (no raised combs). Typically, I like the objective bell to sit above the barrel at about the same height as the thickness of a nickle. If your 40mm scope has more clearance than you may already have room for a larger bell.

Larger objectives are helpful if you shoot during the last several minutes of legal shooting light. IME whitetails seem to come into view at this time of the evening most of the time. I can occasionally see them linger in the tree line as the sun drops. When a buck first appears in low light it takes a quality piece of glass and a reasonable amount of light transmission to evaluate antlers.

It seems that 95% of the hunt is during the 5% of the day when the light is the dimmest. That is why I prefer a 50mm objective lens. If you shoot in "good light", even a 32mm objective will work fine.

Just my 2 cents.
 
For me it's quality over objective size.

Coatings and quality of how they are applied contribute to how much light transferred to your eye. So much so that many 40mm objective scopes see better than some 50 mm objective scopes. I'm also a huge fan of a cheek weld. It's got to be set up so that the shooter's eye is looking into the center. With today's optics you can have all the low light performance you can handle with 40-44 mm...........
 
The amount of light reaching your eye is typically an issue of optics quality & design coupled with magnification vs objective lens diameter.
Given two scopes of identical quality and magnification, the scope with the larger objective lens will provide a larger light column to the shooters eye.

Needless to say, large scopes of poor quality will have issues with light transmission and image resolution.
 
My preference has always been smaller objectives and I only have one scope with a 50mm and that is on my youngest son's 270wsm.
My 35 Whelen has a Diavari 36mm and the other rifles have 42mm objectives (y).

Blessings,
Dan
 
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