Large objective scopes on large calibre rifles

[njc110381]

Hi chaps. This is a subject I've been pondering since shooting my .416 Rigby and realising it's actually not so bad. Does anyone here have a similar gun, I guess .375 and up or a mid bore Weatherby type round with a larger scope fitted?

I ask because a lot of deer shooting here in the UK is done at dawn and dusk, and scopes like the Schmidt and Bender 8x56 are very popular. I appreciate that may be a bit much for it but is there anything on offer that will work with this level of recoil and offer an exit pupil size of 7 at decent magnification for maximum light gathering?

For those who don't know, the average eye can best make use of a 7mm circle of light exiting an optic. Anything bigger than that is wasted around the outside of the pupil and anything smaller produces a dark image because not all of our potential light gathering is used, hence for peak performance manufacturers aim for around 7. 6x42 - 42÷6=7, 8x56 - 56÷8=7 etc. So a x20 scope is at it's best at 2.8x, a little low really.

I'm looking at a Leupold 2-7x33. That'll give me about 5x and still work well at last light whilst winding down to 2x for close up shots. What do you think?

 

[Opposite Pole]

There are a number of scopes with large objectives and a minimum 2x magnification. I’ve got a 1-6x24 on my 375 but am considering putting a 2.5-10x50 Schmidt Bender Polar T96 on it. We do a lot of night hunting for Boar and are generally not allowed to use night/thermal vision equipment nor artificial light and I could use a brighter glass. Often times I can see the animal clearly enough through binos but not clearly enough through the scope. I reckon that above mentioned scope will work just fine. For me a perfect scope for 375 would be 1-8x40 but I haven’t seen one.

 

[Nyati]

The exit pupil of 7 is maximum for a young person (25 years old) , as you get older (60), this value diminishes to 4-5.

 

[V.Veritas]

Have you considered a Schmidt & Bender Stratos 1.5-8x42 with illuminated dot?
On the lowest power you can run it as a red dot, on power 8 is a precision shooting equipment.
It works good for me set in Alaska QD rings.

There are a number of scopes with large objectives and a minimum 2x magnification. I’ve got a 1-6x24 on my 375 but am considering putting a 2.5-10x50 Schmidt Bender Polar T96 on it. We do a lot of night hunting for Boar and are generally not allowed to use night/thermal vision equipment nor artificial light and I could use a brighter glass. Often times I can see the animal clearly enough through binos but not clearly enough through the scope. I reckon that above mentioned scope will work just fine. For me a perfect scope for 375 would be 1-8x40 but I haven’t seen one.

 

[Jeffrey]

Higher end European glass (Swaro, S&B, Leica, etc) tends to absorb more light and have better coatings. Illuminated reticles help with low light as well. Try both of those before a huge objective scope on a big bore.

IMHO, any objective much bigger than 42-44mm is for predators, varmits, and nuisance animals.

 

[ldmay375]

I have 375 Ruger and a 416 Ruger rifles currently with the Schmidt and Bender 1.5-8x42's, FD4 reticle. I like the 42mm for moose hunting in very low light conditions. These are Ruger actions, and I also use the Alaska Arms rings. These may not have "the look" of the the classic big bore scope, but I find them advantageous in low light.
I also like the Zeiss Victory 1.5-6x42 with non-illuminated #4 reticle, unfortunately no longer imported to the U.S. My son has this scope on his 375 H&H and 375 Ruger. This scope and the S&B 1.5-8x42 are first focal plane reticle. I have also used the Kahles first focal 1.5-6x42 on the 416 Ruger.
The 416 Rigby no doubt has more recoil than the rifles that I mentioned, but I would be confident that the S&B scope would withstand it as well as any.

Have you considered a Schmidt & Bender Stratos 1.5-8x42 with illuminated dot?
On the lowest power you can run it as a red dot, on power 8 is a precision shooting equipment.
It works good for me set in Alaska QD rings.

 

[Bushpig4Ever]

On my 9,3x74R is a Zeiss 2.5-10x52 reticle no. 4. Shot lots of bushpigs at night, no artificial light, just the moon.

 

[Scrumbag]

A buddy of mine just picked up a 1.7-13x42 Swaro for his 375H&H for use in Africa and larger deer in the UK.
Kahles used to do (Still do?) a 1.5-8x42 that looks interesting

 

[Ray B]

I shoot a 375 RUM that has a Leupold VX6 4-24x mounted on it. In addition to "hunting" loads with bullets of 250 - 300 grain I do informal target/gong shooting at long range (1000+ yards) with 350 g bullets. Both scope and shooter seem to be holding up well. I don't know what the size of the objective is but it is certainly larger than the standard size objectives in the 40 mm range.

 

[mark-hunter]

hence for peak performance manufacturers aim for around 7. 6x42 - 42÷6=7, 8x56 - 56÷8=7 etc.

I think that number to divide is 7, not 8 to get optimmum performance in theory.
In reality there will be variations to the individual eye pupil.
For example Maritime binocular regardles of brand are ususaly fixed at 7x50.
In rifle optics, 8x56. (dividable by 7) is also very good example.

For other specific optics, you can do the rest of math.
For low light conditions, front lense as wide as possible. I would consider ate least from 50 mm, and upwards, 56 mm, etc.

If the hunting will be combined with walking and stalking, then 50 mm should be reasonable size to keep rifle in handy dimensions.
If the hunt is from the blind, then larger diameters of front lense to be considered.

That is my way of thinking...

 

[Scrumbag]

I shoot a 375 RUM that has a Leupold VX6 4-24x mounted on it. In addition to "hunting" loads with bullets of 250 - 300 grain I do informal target/gong shooting at long range (1000+ yards) with 350 g bullets. Both scope and shooter seem to be holding up well. I don't know what the size of the objective is but it is certainly larger than the standard size objectives in the 40 mm range.

Interesting isn't it. As you say Ray, in N America, ~40mm is standard. Europe, 50mm or larger is seen as the standard and anything smaller is seen as rather sub optimal.

Scrummy

 

[ldmay375]

The Swarovski 1.7-10x42mm with Plex reticle is one of my favorite scopes. It is definitely my favorite 2nd focal plane non-illuminated.
I find this a very versatile scope with the wide field of view on the lower powers. I could use this scope on my rifles from .223 through 416, and not feel short changed. I wish that I had "discovered" this scope earlier.

 

[Opposite Pole]

Interesting isn't it. As you say Ray, in N America, ~40mm is standard. Europe, 50mm or larger is seen as the standard and anything smaller is seen as rather sub optimal.

Scrummy

In many places in Europe night hunting under natural light (moon or man made light pollution) is common practice, particularly for pigs. Under such circumstances you need all the light you can get and it’s in such conditions that the brighter scopes really shine. When hunting deer at dawn or dusk there’s still a lot of natural light available, but not so at night. Also the size of exit pupil does not tell the whole story. I’ve got Zeiss Victory 3-12x56 and Leica Magnus 1-6x24, with zoom adjusted to give identical exit pupil this particular Zeiss is a fair bit brighter under minimal light conditions. Several factors affect it. The Zeiss is a 4x zoom and Leica 6x. Anybody familiar with camera lenses will be well aware of optical differences between “prime” fixed length lenses and zoom ones. Complex subject optics...

 

[Opposite Pole]

For example Maritime binocular regardles of brand are ususaly fixed at 7x50.

In maritime optics brightness as well as ability to hold steady in hands are determining factors. 10x lenses on a deck of a yacht working in the swell when one frequently needs to use one hand to keep from going over the side are impossible to hold. Today pretty much any maritime binos over 7x are electronically stabilised. I had an opportunity to compare my awesome Leica Geovid HD-B 8x56 vs a fantastic Steiner Commander Global 7-50 maritime glass. At sea Steiner wins, brightness is near identical but the 7 vs 8 magnification is enough to make them way easier to hold.

 

[Scrumbag]

In many places in Europe night hunting under natural light (moon or man made light pollution) is common practice, particularly for pigs. Under such circumstances you need all the light you can get and it’s in such conditions that the brighter scopes really shine. When hunting deer at dawn or dusk there’s still a lot of natural light available, but not so at night. Also the size of exit pupil does not tell the whole story. I’ve got Zeiss Victory 3-12x56 and Leica Magnus 1-6x24, with zoom adjusted to give identical exit pupil this particular Zeiss is a fair bit brighter under minimal light conditions. Several factors affect it. The Zeiss is a 4x zoom and Leica 6x. Anybody familiar with camera lenses will be well aware of optical differences between “prime” fixed length lenses and zoom ones. Complex subject optics...

There is definitely something to be said for keeping the zoom factor not too great. Swarovski stopped making their Z4i line of scopes that apparently had the highest light transmission of any variable Swaro have ever made. Is a shame, I wish I'd bought more.

Scrummy

 

[Goose Cracker]

I prefer scopes with larger objective lenses - almost everything I own has a 50mm objective lens. Currently have a VX6 1-6x24 on my 375, but have a Trijicon 2.5-12.5x42 on it's way that will top my 375. Thinking the VX6 will top a 416 at some point.

 

[Red Leg]

Remember that eye-relief is at least as important as exit pupil on a heavy recoiling rifle. Dialing up into the higher ranges, particularly in a hunting situation where we have a tendency to crawl up the stock can mean a real chance for a injury. I would think the need for such a combination in the UK or the continent would be somewhat limited. I have sat freezing over moonlit bait piles in snowy Germany at midnight hunting boar, but I don't think it ever crossed my mind to do so with a .375 much less a .40. And in Africa, such a scope is simply not needed or even particularly desirable on such a caliber. An exception would be a leopard blind, but again, a .40 would be my last choice for such game. And a 50mm is certainly not needed even there if you are using a quality scope with an objective in the 40's. My other objection to 50's is that - to me at least - regardless of weight, they ruin the balance of a rifle that is going to be carried a lot. Obviously, from a stand, it doesn't matter so much.

 

[The Engineer]

On both my 300 Win. and 416 Rigby rifles I have Zeiss Victory HT 1.5-6 x 42s with illuminated dot for many of the reasons stated above. I can easily shoot 1.0" groups at 6x and see no requirement for higher magnification on a big/dangerous game rifle. However, the prime reason I much prefer the smaller objective scopes is they can be mounted as low as the eyepiece clearing the bolt will allow. This lower mounting secures a much better check weld (Essential for finding the target quickly.) and, reduces perceived recoil due to the stock accelerating (slapping) into the cheek from the "looser" check weld with high mounted large objective scopes. From my standpoint the high zoom ratio large objective scopes are technically interesting but not as practical for African hunting.

 

[Timbo]

I've had a Weaver fixed 4 power on my 458Win Mag for the past 15yrs. A simple, solid optic with a clear image that holds zero. So far it's withstood everything international baggage handlers, bouncing around on the back of a truck and Africa generally has thrown at it.

IMO at the ranges when hunting DG, I think a variable scope is more of a hindrance than an asset. Even when practising on the range, I think it's better to learn to shoot accurately with the scope fixed, rather than to screw it up to max magnification to get that nice group. In practising at the range with my fixed 4 power, I've simply leant to use my rifle accurately - which has paid off every time during the hunt.

As long as the scope has clear imagery and depenably holds zero - I think that's all you really need. Because, in the heat of the moment with the adrenaline pumping, remembering to screw down your variable scope is usually the last thing on your mind: so I'd go for a fixed power - with wide/rectangular eye piece (giving a wide field of view for easy target aquisition) - and you'll have no problems.

Just my 2c!

 

[Shootist43]

njc, when you start talking .4 caliber and above you are talking DG for the most part. Think about this for a moment, at what distances is DG normally shot at? I think a fair bet is under 75 yards and most often a good deal less than that. The scopes on my DG rifles are either 1-4X or 1.5-5X 20 or 24. I read somewhere that scope power and I think objective lens diameter is an age related thing. Older guys seem to prefer lower powered scopes while younger shooters prefer more magnification with larger and larger objective lenses. Like Red Leg mentioned specific hunting techniques require larger lenses to gather moon light etc. but they are best used on smaller caliber rifles.