Scope objective lens size?

[F21FALCON]

Looking for a new scope for a rifle I just purchased. It will be suppressed. It’s a .308 and I am hunting in the Texas hill country and West Texas. Shots will be 250 yds at furthest. My question is what objective lens size to go with? 40 or 50? Is going with the 50 going to make a real difference in low light conditions? Been out of gun hunting for a while, so wanted to get some input from guys who really know. It will be used for whitetail and hogs. Thanks in advance.

 

[Q_Sertorius]

This seems helpful:

Low light comparison of 17 scopes

There are always constant threads of discussions about “glass”, low light use, etc of scopes here. The last couple of week I have gotten many more questions about it (due I believe to SWFA being back in stock), so while working with a couple of scopes on other things, I brought out 10 different...

rokslide.com

 

[Dave Thomas]

40 should get you through legal hunting hours. Now hunting hogs at night might be a different.

 

[Thinkingman]

I thought going up to 50mm was going to seem bulky but now I'm glad I did it.
It's 20 percent more light gathering.
To me, that's significant.

 

[F21FALCON]

Thanks guys.

 

[F21FALCON]

I thought going up to 50mm was going to seem bulky but now I'm glad I did it.
It's 20 percent more light gathering.
To me, that's significant.

I was kinda wondering about that. The rifle I got I can change the cheek piece height so the higher rings shouldn’t make it awkward trying to get sight picture.

 

[jaredg]

These days it's 56mm or nothing for me. My 50mm obj seem small to me now. However, I still field a lot of and really enjoy my NF ATACR 4-16X42.

The older my eyes get, the more I favor big objectives.

 

[blksno]

I was kinda wondering about that. The rifle I got I can change the cheek piece height so the higher rings shouldn’t make it awkward trying to get sight picture.

50mm vs 40mm is a difference of 10mm total. 5 on top which is irrelevant...and 5 below that causes you to raise the scope higher to clear the barrel.

5mm is less than .2 inches difference in cheek height.

 

[F21FALCON]

50mm vs 40mm is a difference of 10mm total. 5 on top which is irrelevant...and 5 below that causes you to raise the scope higher to clear the barrel.

5mm is less than .2 inches difference in cheek height.

Ok thanks. Didn’t think of it like that.

These days it's 56mm or nothing for me. My 50mm obj seem small to me now. However, I still field a lot of and really enjoy my NF ATACR 4-16X42.

The older my eyes get, the more I favor big objectives.

Same on the eye situation here! That’s why I was considering 50mm.

 

[Kauaihunter]

Better glass will serve you better than larger objectives. Everyone’s eye is different and only X amount of light can be taken in. YMMV

I’m not discounting larger objectives, I run 40, 42, 50 and 56. I like the 50 best.

 

[ianpadron]

50mm vs 40mm is a difference of 10mm total. 5 on top which is irrelevant...and 5 below that causes you to raise the scope higher to clear the barrel.

5mm is less than .2 inches difference in cheek

This is the wrong way to compare objective size.

You need to look at area, not diameter. A 50mm objective has almost 60% more lens surface area to gather light than a 40mm scope. That is significant.

For guys chasing the absolute best low light performance, a larger objective scope is noticeably brighter so long as the glass is comparable.

 

[JimIsland]

Buy the best glass you can afford in a 56mm and don't look back! If you are trying to stay on the more economical side, check out an Accupoint 2.5-10X56. Also, I saw a Meopta Meostar on sale somewhere for like 1100.00 which is a screaming deal. It was the 2.5-15X56mm variation.

 

[blksno]

This is the wrong way to compare objective size.

You need to look at area, not diameter. A 50mm objective has almost 60% more lens surface area to gather light than a 40mm scope. That is significant.

For guys chasing the absolute best low light performance, a larger objective scope is noticeably brighter so long as the glass is comparable.

100%correct...and absolutely irrelevant to my point.

 

[nm.otter]

Entirely dependent on the magnification. Ongoing discussion here. Read first three posts, then skip to page 4-5 and follow along.

 

[ianpadron]

100%correct...and absolutely irrelevant to my point.

The dude is asking about low light performance, not clearance, Clarence

 

[Southern Lights]

~40mm scopes are lot lighter than 50mm scopes. I only use 40-44mm range objective scopes on my hunting rifles and can't tell enough difference in low light for it to matter vs. 50mm. If it does matter, it probably means it's time to bring out the thermal. I think a good reticle makes a big difference here in low light also.

You just need to decide if the theoretical last couple minutes of dim shooting is worth the much bigger and heavier scope you are hauling around all day. I like lighter and more compact scopes for walking around.

 

[Tmac]

Where I hunt you can shoot 30 minutes before sunrise and 30 minutes after, I’ve not had any issues with a 33mm objective at or under 5x. Most of my scopes are around 40 mm - 44mm, no issues there either.

While I can’t say for sure, imo quality of glass and especially coatings is more important than a few extra mm of objective size, for the afore mentioned 30 minute rule. Earlier or later than 30 min is outside my experience,

 

[nm.otter]

33mm at 5x = 6.6mm exit pupil.

 

[ianpadron]

Every single one of my scopes is either 42 or 44mm. I've never wanted "more light" in a hunting situation, although I think that has more to do with picking reticle styles that actually function on low mags in low light.

The Bushnell Elite donut of death is the best I've used, its like an ACOG on low power, SWFA mil quads in 3-9 and 10x a close second. I've got a pretty even mix of those 3 scopes, love em.

50s or 56s will give you more performance, but you gotta ask do you actually have a use for it.

 

[blksno]

The dude is asking about low light performance, not clearance, Clarence

...And the question I specifically replied to AND QUOTED is referring to rings needed to clear a larger objective and an adjustable cheep piece to stay aligned.