Rifle Scopes Why the need for 35x magnification?

[ShtrRdy]

I was looking over a recent article on Precision Rifle Blog which talked about the scopes "The Pros" used.
The scope used by most competitors was the Nightforce ATACR 7-35x56. What do competitors use the 35x power for?

 

[Seymour Fish]

I was looking over a recent article on Precision Rifle Blog which talked about the scopes "The Pros" used.
The scope used by most competitors was the Nightforce ATACR 7-35x56. What do competitors use the 35x power for?

Rumor is view thru glass optimal at 15-20 X where these are mostly run

 

[_Windrider_]

I was looking over a recent article on Precision Rifle Blog which talked about the scopes "The Pros" used.
The scope used by most competitors was the Nightforce ATACR 7-35x56. What do competitors use the 35x power for?

ever try to see a 36" square target at 2 miles on 15x?

 

[avidflyer]

Hell I use a 60x for Fclass at 600 and 1000

 

[phlegm]

Rumor is view thru glass optimal at 15-20 X where these are mostly run

This is more descriptive than prescriptive, but I agree. Everything works best in the middle of its range of performance. An engine that red lines at 8k RPMs should be smooth as silk around 4k, but if it only goes up to 4.2k, it's going to be screaming at 4k.

I doubt many use all 35x that often. I've only used mine there once or twice. Its nice when you need it, though.

 

[Fred @ Bison Tactical]

IMO - most of us are shooting at lower mag most of the time - like 15-18X for most of the stages in competition. However there are certainly times when higher magnification is very useful

a. zeroing - and checking groups - its much easier to hold a small group if you can see the paper target well
b. plate racks - when you don't have to locate targets because all your targets for the stage are in one spot, you don't need lower mag - its also great to be able to see where on the plate you impacted, and sometimes better magnification can help
c. ELR type matches like the Nightforce ELR match in Wyoming where average target distance was 1100 yards, and the farthest target was 2100 yards

The bigger problem for higher power scopes (particularly the newer designs with higher than 5X range) is that the reticle is optimized for viewing at some particular magnification. You can notice this on most 5-25 scopes. You can't see the reticle hashes at 5X, and at 25X the wind dots in a Tremor 3 are huge. So the reticle choice and where its optimized for viewing can have a big impact. This is magnified on a wider than 5X range and so you def need to consider this on like the 7-35 or 5-45 scopes for the tactical style reticles we use with first focal plane scopes.

 

[AznTactical]

Because the eyebox & eye relief are much more flexible at 20-30x when the optic maxes out at 35X.
My S&B PMII maxes out at 25X but she shines at 15-20X.

 

[koshkin]

Because the eyebox & eye relief are much more flexible at 20-30x when the optic maxes out at 35X.
My S&B PMII maxes out at 25X but she shines at 15-20X.

That is mostly a function of exit pupil, not of the maximum magnification.

ILya

 

[Fred @ Bison Tactical]

@koshkin - I would love to hear your thoughts on what different choices are available to different manufacturers when building a scope. It seems like for most of the upper tier scopes it is more splitting hairs to find differences than anything else. However I bet some of them are making decisions that are just not identified externally - for example what colors to optimize with the coatings, or low light gathering verses contrast etc.

I would love to have some list of all the things to consider when choosing an optic - really specific to the optical choices - not like features of the mechanics like reticle choice or turret click feel etc.

 

[Im2bent]

Ever try to see some 36C's at 2 miles????
Could not resist..

 

[koshkin]

@koshkin - I would love to hear your thoughts on what different choices are available to different manufacturers when building a scope. It seems like for most of the upper tier scopes it is more splitting hairs to find differences than anything else. However I bet some of them are making decisions that are just not identified externally - for example what colors to optimize with the coatings, or low light gathering verses contrast etc.

I would love to have some list of all the things to consider when choosing an optic - really specific to the optical choices - not like features of the mechanics like reticle choice or turret click feel etc.

Once you get to the high end, almost everything performs well and a lot of it is indeed splitting hairs.

Nevertheless, there are differences in specs, differences in feel and differences in optical performance, though not huge ones. Once you have them side-by-side, you can kinda tell. I am setting up another "high end" side-by-side with 50mm scopes to sorta revisit that toward the end of October.

As far as performance across the magnification range goes, it is a really good question and there is a lot there that depends on the manufacturer's design goals.

I am going to do another Youtube livecast this week. Maybe this will make a good discussion topic. Let's call it "riflescope optimization". I do not see it covered particularly well anywhere, so I think it is best I do it in an interactive format: go over a fundamental decision matrix of sorts, then open it up to a Q&A.

ILya

 

[AznTactical]

That is mostly a function of exit pupil, not of the maximum magnification.

ILya

ah yes, I remember watching a video of yours demonstrating exit pupil. Thank you sir!

 

[Seymour Fish]

This is more descriptive than prescriptive, but I agree. Everything works best in the middle of its range of performance. An engine that red lines at 8k RPMs should be smooth as silk around 4k, but if it only goes up to 4.2k, it's going to be screaming at 4k.

I doubt many use all 35x that often. I've only used mine there once or twice. Its nice when you need it, though.

You ain’t run many hot rods. 8 K rpm motor generally has a power band 2500 wide if you are lucky, unless variable valve train/variable intake runners, high $ computer/injection. But I take your point

 

[Center Mass]

I don't really see the need for an scope with anything much above 25x. A few weeks ago, i as shooting at a 36 inch target at 2700 yards while at about 13x. This was done out of necessity because I needed an additional 10 mils of holdover on top of my max'd out elevation. My Charlie Tarac mount was not ready yet so in order to be able to have the 10 mils visible, I had to dial down to +/- 13x. While this was not ideal by any means, I assure you it was quite doable. I did get some hits but I think scope shadowing up top was difficult to avoid while looking so far down in the FOv. Now that my CT is ready to go, I will likely not use more than 20x at the same distance and I am sure I will do better next time.

I personally almost never shoot at max magnification on any scope. I find that the eye box gets too finicky, wobble increases, and in some cases, the image gets a little darker. When I do max out the magnification it's usually either to PID something or see impacts.

 

[_Windrider_]

I don't really see the need for an scope with anything much above 25x. A few weeks ago, i as shooting at a 36 inch target at 2700 yards while at about 13x. This was done out of necessity because I needed an additional 10 mils of holdover on top of my max'd out elevation. My Charlie Tarac mount was not ready yet so in order to be able to have the 10 mils visible, I had to dial down to +/- 13x. While this was not ideal by any means, I assure you it was quite doable. I did get some hits but I think scope shadowing up top was difficult to avoid while looking so far down in the FOv. Now that my CT is ready to go, I will likely not use more than 20x at the same distance and I am sure I will do better next time.

I personally almost never shoot at max magnification on any scope. I find that the eye box gets too finicky, wobble increases, and in some cases, the image gets a little darker. When I do max out the magnification it's usually either to PID something or see impacts.

No one should shoot at max except for zeroing. The primary purpose is PID of targets or if you’ve dialed and have to hit something you can take the sweet time to aim at. I usually shoot on my 5-25 around 12-15. However sometimes I’ll use higher but I dial down, find the target then dial up. But yes if holding over that’s a major consideration in what magnification to use

 

[beetroot]

Most people will be unlikely to use 35x in a competition but it's nice to have it just in case.
Where as almost no one will ever use less than 8x magnification, so you aren't really sacrificing anything.

The ATACR 5-25 tunnels on the low end anyway, thus is more like a 7-25x scope.
So the 7-35 makes more sense for someone who's looking at an ATACR.

 

[Fred @ Bison Tactical]

I guess we could pose the other end of the spectrum as a question as well - why would anyone ever need a 5X on the minimum side of the magnification scale?

I am almost certain I have never used minimum magnification on my 5-25 scopes, while I often use the maximum end (paper zero for example). I would happily sacrifice low end magnification for some upper end range if the price and optics were comparable.

I think this is the entire reasoning behind the 7-35 NF ATACR...

 

[_Windrider_]

I guess we could pose the other end of the spectrum as a question as well - why would anyone ever need a 5X on the minimum side of the magnification scale?

I am almost certain I have never used minimum magnification on my 5-25 scopes, while I often use the maximum end (paper zero for example). I would happily sacrifice low end magnification for some upper end range if the price and optics were comparable.

I think this is the entire reasoning behind the 7-35 NF ATACR...

Lower end for wider FOV. Easier to find targets while looking through glass. Dial down when switching dial up once ID’d

 

[HousePlant]

Because spotting scopes are expensive and heavy.

 

[Fred @ Bison Tactical]

I agree with finding targets better at lower magnification, but I never use 5x on my 5-25, MAYBE I would go to 10 or possibly 8 but very unlikely, and I never go to 5x...

 

[_Windrider_]

I agree with finding targets better at lower magnification, but I never use 5x on my 5-25, MAYBE I would go to 10 or possibly 8 but very unlikely, and I never go to 5x...

One of the big reasons we don’t use the bottom mag is because in our FFP scopes the reticle are useless for holding.
But I try to treat the magnification like my turrets. Whenever I get off the gun I dial back to the zero stop and the magnification to the lowest setting. That way when I get back on the gun I have the widest FOV to find my targets. Dial up. Close the bolt and go

 

[Mike Casselton]

A couple of things that have been overlooked so far.

1. Some people don't shoot competition and want to see aiming point, impact and their target as a bigger picture/maybe more clearly.

2. Age of the shooter.
As a shooter's eyesight diminishes the need to turn the ocular lens out becomes a necessity to focus the reticle. In some scopes, this makes the magnification appear to lessen by a small amount. That small amount can be very important to someone fighting diminishing vision.

There are other reasons, but I find these two to be pretty important.

 

[Clearlight]

Depends on the situation. In good conditions, F class guys are up on high zoom a lot.
Holding on a small plate with a lot of impacts on it is a lot easier with some zoom, if
conditions allow, although most PRS matches are shot from 10-20 ish zoom.

Ive hit at 2700 meters on 5x, but there was some luck involved as mirage was terrible
in 40 C degree heat. I’ve shot that same target mid winter, early morning on 40x, and
it was a much easier job seeing the misses and impacts. Not having to drag a spotting
scope along while climbing to a high firing point is appreciated, just use the rifles optic.

Back in the day, some of our work rifles ran Schmidt’s with max 12x zoom. Quite often
the spotter had identified a target that the shooter had difficulty seeing, due to the
disparity in zoom. Having 35 or even 50x available is fantastic when you need it: just
like a 500 bhp motor, you don’t have to use it all the time but its great when you do.

 

[hafejd30]

For those that want NF ATACR the 7-35 is generally regarded to have better glass then the 5-25. Most who want higher mag don’t consider the 4-16 so we’ll leave that out

As noted the sweet spot for an optic isn’t on the top end but generally in the mid range. Burris XTRII are excellent examples of this

Many would rather give up the 5 vs 7 on the low end to gain the 25 vs 35 on the high end

Rumor is (I say rumor because I haven’t checked myself) that the 5-25 tunnels below 7-8 power. So basically you gain nothing on the low end vs the 7-35

Finally there’s the “have it and not need it vs need it and not have it” mindset

You can always back the mag off. When you need or want more there’s always a limit. Depending where you live and what your use is for the rifle will depend how much you truly take advantage of each scopes offering

 

[superde]

Just to throw this out there, but people keep saying that for PRS competitions people don't/shouldn't run their scopes at max magnification. While mostly true, there are 2 Golden bullet winners that ran their scopes at max magnification (25x and 27x) 99% of the time FWIW.

 

[phlegm]

For those that want NF ATACR the 7-35 is generally regarded to have better glass then the 5-25. Most who want higher mag don’t consider the 4-16 so we’ll leave that out

As noted the sweet spot for an optic isn’t on the top end but generally in the mid range. Burris XTRII are excellent examples of this

Many would rather give up the 5 vs 7 on the low end to gain the 25 vs 35 on the high end

Rumor is (I say rumor because I haven’t checked myself) that the 5-25 tunnels below 7-8 power. So basically you gain nothing on the low end vs the 7-35

Finally there’s the “have it and not need it vs need it and not have it” mindset

You can always back the mag off. When you need or want more there’s always a limit. Depending where you live and what your use is for the rifle will depend how much you truly take advantage of each scopes offering

I've looked at the 5-25 specifically for this. The concern seems to come from the S&B 5-25 that tunnels (decreasing FOV and no change in image magnification) at low power. See:

The NF 5-25 also exhibits decreasing FOV, but continues to decrease image magnification as well. As such, while it might be splitting hairs to some extent, calling it a 7-25x is inaccurate.

The published FOV on the 5-25 is 18.7' and the 7-35 is 15'. If seeing those 3.7' at 100 yards is a high priority, we have options. I doubt too many shooters are making their decision on this, though.

 

[upSLIDEdown]

Just to throw this out there, but people keep saying that for PRS competitions people don't/shouldn't run their scopes at max magnification. While mostly true, there are 2 Golden bullet winners that ran their scopes at max magnification (25x and 27x) 99% of the time FWIW.

Truth bombs.

I run 35x when zeroing, load dev, and on long range prone stages as long as mirage isn't terrible.

 

[schmi015]

IMO - most of us are shooting at lower mag most of the time - like 15-18X for most of the stages in competition. However there are certainly times when higher magnification is very useful

a. zeroing - and checking groups - its much easier to hold a small group if you can see the paper target well
b. plate racks - when you don't have to locate targets because all your targets for the stage are in one spot, you don't need lower mag - its also great to be able to see where on the plate you impacted, and sometimes better magnification can help
c. ELR type matches like the Nightforce ELR match in Wyoming where average target distance was 1100 yards, and the farthest target was 2100 yards

The bigger problem for higher power scopes (particularly the newer designs with higher than 5X range) is that the reticle is optimized for viewing at some particular magnification. You can notice this on most 5-25 scopes. You can't see the reticle hashes at 5X, and at 25X the wind dots in a Tremor 3 are huge. So the reticle choice and where its optimized for viewing can have a big impact. This is magnified on a wider than 5X range and so you def need to consider this on like the 7-35 or 5-45 scopes for the tactical style reticles we use with first focal plane scopes.

I shot that match in Wyoming this year running a 5-25 Schmidt and on a couple stages even at 5x I wasted some time looking for targets. Made me think my 3-20 ultra short might have been better. Even the furthest ones away weren't shot above 20x. I used a p4f reticle and it worked well for me. I ideally like p4f, LRR-Mil and the gen2xr. That place will humble you with wind calls though.

 

[rottenruger]

Ever try to see some 36C's at 2 miles????
Could not resist..

She ain't gonna like you checking them out through a riflescope.......

And then again, she might!

 

[10X Rifles]

My 7-35 ATACR sits on my Vudoo F-Class rifle. Only Nightforce scope with enough magnification, that parallax goes below 50 yds.

 

[clcustom1911]

Ever try to see some 36C's at 2 miles????
Could not resist..

Wrong dimensions.

32DDD or 34DD for the win.