40 Vs. 50 scope


June 25, 2007, 06:18 PM
Newbie question. Sorry. Setting aside any price differential is there any DISadvantage in getting a 3-9x50 scope instead of a 3-9x40 scope? I might be able to pick up a Nikon ProStaff 50 for the same price (within $5) as a 40.

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June 25, 2007, 06:59 PM
Only downside is you need higher rings to for the scope bell to clear the barrel which sometimes makes for a less comfortable sight level and awkward cheek to stock position.

June 25, 2007, 08:00 PM
if you plan on shooting near, dawn. or dusk, the 50 mm is going to allow in much more lights, which makes a big diff. If this is for target work, the 40 will be fine.

June 25, 2007, 09:43 PM
Don't be suckered for a lesser quality just to get a bigger number. Yes,a 50mm in the same quality as the 40 will be a beter light gathering scope in poor light situation but as others have said can add weight, size and mounting/cheek weld issues to the whole mix. For $5 price difference the 50 seems to be a no brainer but depending on the intended use of this gun it can go either way

June 25, 2007, 10:12 PM
Bear in mind that a 50mm objective can't deliver any more useable light than a 40mm objective at magnifications under about 6X in ideal circumstances.

Zak Smith
June 25, 2007, 10:29 PM
The thing that people always forget when discussing objective size is the exit pupil. Yes, the adult pupil can't dilate to more than about 7mm, however, the large the exit pupil of the scope (even larger than 7mm), the "easier" it will seem to obtain and maintain a "clear" sight picture through the scope. Small exit pupils are not forgiving for eye position; a small change in cheek weld can produce the "black ring" which seems to encroach from one side and obstruct the field of view.


June 26, 2007, 04:55 AM
True, But i am still not a fan of the scope "center line" being to high from the "center line of the bore"

50mm would be the largest for me...
on that note, I have not tried a 56mm scope.. yet..

Zak Smith
June 26, 2007, 11:35 AM
Agreed on center line. The problem with 99% of "sporting rifles" (and even many advertised as "sniper / tactical" rifles) is that they still use stock geometry that was appropriate for iron or "open" sights, which are usually within about 1/2" of the bore line. Many aftermarket stocks address this to some degree, and then there is the army of stock packs, pads, etc, which people add to raise their cheek.

June 26, 2007, 04:12 PM
I went for the 40x scope for a couple of reasons. One is that I figure it'd be a bit of a PITA to mount the 50x and two the "within $5" thing didn't work out so the 50x was an extra $50...

BTW Cabela's is having a special deal. Spend $150 and get an instant $30 off the bill. My $149.95 Nikon ProStaff 3-9x40 wound up costing $129.95...

I had to buy a Cabela's post card for 25 cents to bump the transaction over the magic $150 mark.

Gary O
June 26, 2007, 04:46 PM
Scope don't "gather" light. If a 50mm is "brighter", I can't see it. Besides a higher, larger, heavier objective scope messes with the balance and looks of a nice rifle, IMHO. This whole larger objective thing was to get folks thinking that they needed a larger scope to suck in light when in the end it was just a way to sell more scopes.

June 26, 2007, 05:03 PM
Even on a "sporting" rifle designed for a scope (e.g. my Weatherby Vanguard Sporter), I like the 40, because I can use low rings.

With the scope tucked nicely close to the receiver, I get a comfortable, instant, solid cheek weld, which is fine because the Weatherby comb recoils away from your face, not towards it.

The 50 gathers more light than the 40. The downsides? It's heavier, it's bulkier, it has to be mounted higher, and it gets hung up on things more easily in the field.

Light gathering means more at higher magnifications. If you don't need to use the maximum magnification of the scope when it's getting dark, 40 vs. 50 is less of an issue. Many big-game hunters don't even like to use more than 6x, especially for offhand shooting, or shooting with a makeshift rest.

Just going to shoot at the range? Hell, get the bigger scope if you want. But in the field, there are other things to think about.

EDIT: What "gathering more light" means is that a scope with a bigger objective lens will take more light from a larger surface area and focus it back to your eye, than one with a smaller objective. I have to say that I, too don't see that much difference. The quality of the scope matters a lot more. Cheap scopes are usually darker, top-quality scopes are brighter. TANSTAAFL.

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