40mm or 50mm?


Nov 13, 2001
Kalispell Montana
I was was about to purchase a 6.5-20 vari-x3 scope and was wondering if anyone can tell me if their are any noticeable advantages of having a 50mm objective over the 40mm, weight is not a problem.Any suggestions on your personal experiences would be greatly appreciated.Thanks
If they're both the 1 inch 6.5 x 20 Vari-X III I'd say there's no big difference. The 40mm can be a bit lower so your cheekweld might be no problem, getting the 50mm version may require a pad on the stock to get a good comfortable cheekweld.

I generally figure a 5mm exit pupil for light transmission and that's only a 2x difference between the two, so your limited to 8x vs 10x on a 20x max scope. You're stuck on the low end eitherway once it gets a little dark outside, again no big difference.

If it were me buying the scope, I'd go for the 40mm version.

[ 12-06-2001: Message edited by: Dave King ]
I'm with Dave. I prefer my scopes mounted as low as possible. I have no need for anything larger than 40mm.
Wouldn't the Leupold Long Range be a better choice with side focus, stronger 30mm tube, more stable adjustments, and more (72 MOA) elevation adjustments, despite the more cumbersome 50mm objective for long range hunting and shooting? Just a thought.

I was at a local gun shop and the owner said the Pentax rep. was in a while back and showed them the facts. He said all of their tests show no advantage of a 50mm obj. with the 1" tubes, the tube is just too small.

The 30mm tube was another story, it takes full advantage of the 50mm and and increase in light transmission was apparent in these. They said also, the fact is people like the big end and the have to make what people want to stay in buisness, a plain gimmick in his words and it sells scopes.

My brother bought a 5.5x22 Nightforce a few days ago and I'm in love with it after one time out.
I gotta chime in on this one.. I know there are alot of guys that swear by leupold but have they tried a Nightforce??? I have the 3.5-15X50mm NXS, I gotta tell ya it is as bright as any of the euro scopes if not brighter and in my opinion lupy's can't hold a candle to them. ( just my opinion ) and I have had to many lupy's to count, I was one of the "there is no better than lupy guys ) boy was I wrong!!!!
In the same price range I think you find Nightforce hard to beat.
I think you'd be better off buying a Weaver Grand Slam 6-20x40mm! I owned a 8-32x56mm NightForce for 7 years and hunted with it all the time! I know good optics and believe you me the Weaver Grand Slam will save you money and I think is better than the VaiXIII scopes. I can buy the Luepolds wholesale but nod on them as I think there are better out there hence my purchase of two 6-20x40mm Weaver Grand Slams!! Look through them then look through others and you decide. I had the Nightforce side by side and even though it had a 56mm obj. the Weaver was just as good. Granted it doesn't have an illuminated reticle like the NightForce but we can't have it all. Truely a better scope in my opinon than the Luepolds!!!!!!!
I have and use Leupold, Kahles and Swarovski scopes. I was looking for something to put on an .244 Ackley which is just about ready to go to the bench. I will use it for both day and night shooting. After comparing and studying and looking, I purchased the new Leupold LPS 2.5 X 10 X 45. I wanted to stay as low as possible but also wanted the low light abilitys as well as night shooting at coyotes. The scope has a 30 mm tube and I will be able to keep it low. What a piece of glass it is. The euro scope companys need to stand up and take a look at their new US compition.
I recently acquired a Leupold LRT 8-25x. Yes, it has a 30mm tube, but be aware that the outside objective is 58mm, while the outside objective of the Leupold "40mm" 8-25 is 51mm. That only .275" greater.

And, if you use the Burris signature "high" model, the lift isn't too much. The 30mm Burris high rings are actually midway between the 1" medium and 1" high. On a one-piece Leupold base, I can get a decent cheek weld on a standard stock. I've seen a lot of 40mm sitting on weaver bases that sit higher.

It's just about sweating the details and picking the right hardware setup.
Let me throw yall a curve!! See if you can
find an IOR brand scope to look thru, it wont
matter what obj. it is as the glass is as
good as Swaroski(spelling ?) for a third of
the price. They have a reticle that is second
to none. 10mil's worth of hold points below
the cross and 50moa on the vert. adj. Check it out, you will like it!!!
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