24hourcampfire.com
24hourcampfire.com
Previous Thread
Next Thread
Print Thread
Hop To
Page 1 of 4 1 2 3 4
Joined: Jun 2000
Posts: 11,263
RickBin Offline OP
Campfire Outfitter
OP Offline
Campfire Outfitter
Joined: Jun 2000
Posts: 11,263
It's time again for me to thank John Barsness (our own Mule Deer) for his latest exclusive (and particularly timely) Campfire article "Testing Riflescopes", which can be found on the Home Page and by clicking the link.

Please use this thread to ask John questions about the article.

Thanks John, and Happy Birthday. smile


"What we obtain too cheap, we esteem too lightly: it is dearness only that gives every thing its value. Heaven knows how to put a proper price upon its goods; and it would be strange indeed if so celestial an article as freedom should not be highly rated." Thomas Paine
BP-B2

Joined: Mar 2007
Posts: 950
B
Campfire Regular
Offline
Campfire Regular
B
Joined: Mar 2007
Posts: 950
Thank you John for the thoughts on this subject. Interesting to read on the change in testing over the years as the technology advanced and as the use refined the common practice with the optic.
Did not know that you and Craig had worked together. That must have been some spicy conversation in the break room back in the day.


I used to only shoot shotguns and rimfires, then I made the mistake of getting a subscription to handloader.......
Joined: Nov 2002
Posts: 33,529
E
EdM Offline
Campfire 'Bwana
Offline
Campfire 'Bwana
E
Joined: Nov 2002
Posts: 33,529
John,

Have you considered a consistent method for testing scope durability, ability to hold zero, etc., when "thumped", etc? Particularly given the posts on same of late.


Conduct is the best proof of character.
Joined: Sep 2012
Posts: 371
O
Campfire Member
Offline
Campfire Member
O
Joined: Sep 2012
Posts: 371
Hello John,

I really enjoyed reading your article too. According to your observations, here is the state of the art:

a) Current scopes are very good in terms of being sealed and weatherproof.
b) The optical quality of most premium scopes is very good too.
c) Even the most well-known brands, seem to fail to retain their zero or follow a desired elevation adjustment.

I agree with the above assessment. I'd add the following observations: The main trend in the recent years has been making scopes with more zoom range. First we had the 3X zoom range (such as 3-9X), then it became 4X (3-12X) and now we are being offered 6X and even 8x zoom ratio in the latest Swarovski and Zeiss products. It is also becoming "normal" to produce hunting scopes with larger main tubes (34mm tube on Schmidt and Bender Polar and now the huge 36mm tube of Zeiss V8). The result is that we have heavy, ugly and ultra expensive scopes with features that we really don't need. A high-quality scope with magnification of 1.5-6X and objective of less than or equal to 42mm is good enough for nearly all kind of big-game hunting. A little more power (say 12X) is good for zeroing-in and target shooting but not really needed for hunting. Larger objectives (say 56mm) are good because they enhance optical resolution and also enlarge the exit pupil but the weight and bulk they add is a problem. (The weight of the scope is being added to the top of the rifle which is the worst location to add weight. It also adds to the stress that mounts must withstand)

Zero retention is a basic requirement but we hardly see it being advertised or discussed in marketing literature. Few manufacturers want to talk about it. A scope's robustness can only be verified until you buy it, mount it, zero it and use it. Even then, it could be that one particular sample of a scope works well and exact same scope model used by someone else fails.It is somewhat correct that this issue is caused by poor material and poor quality control (the economics of scope manufacturing you mentioned in your previous article). But let me point out the real cause:tilting the inner tube that holds the reticle and the erector lenses is a bad idea.

In virtually all hunting rifle scopes on the market today, an inner tube holds the reticle and erector lenses. This inner tube is attached to the main scope housing at the rear using a two-dimensional joint such that it's front end can tilt up and down (elevation) or left and right (windage). The front end of the inner tube is held by the elevation nob, the windage knob and a supporting spring. This assembly is fragile and has many mechanical weaknesses. For example: when the inner tube is tilted, only one single point from the elevation knob's stem can touch it. The point of contact is not a surface, not even a line, just a single point! (Pick up to two cylindrical objects such as two shotgun shells. Hold one in your hand horizontally then tilt it a bit upwards. Hold the other one vertically and try to touch the side of the first shell as if this is your elevation knob. Observe how the two shells touch.)

When we dial elevation and windage, the contact points that hold the inner tube shift around and this causes irregularities in the position of the reticle. The rear hing also needs to be very precise to keep the inner tube in exact same tilt under strong recoil forces. This method of holding an inner tube at a precise tilt using two knobs and a spring is simply not robust enough to handle the recoil of a high power rifle.

[Linked Image]


As long as a scope's mechanical design is as I explained above, then it is susceptible to failure. Machining the parts better, using brass parts, or better quality springs would not solve the fundamental weaknesses shown above. We need to address the root of the problem and solve the "zero retention" problem once and for all! Being a PhD researcher with some knowledge of optics and mechanics, I have devised some solutions for this problem myself. This thread is not the right venue to get into technical details but if I see you at Shot Show this year, I would be happy to discuss these new solutions with you. laugh

Thank you again for writing these articles which address real issues with modern rifle scopes. I hope articles like these start a dialogue and get manufactuerers' attention so that the problems of mechanical reliability are addressed at a fundamental level.

Sincerely,
-Omid

Last edited by Omid; 12/04/17.
Joined: Jul 2001
Posts: 59,898
M
Campfire Kahuna
Offline
Campfire Kahuna
M
Joined: Jul 2001
Posts: 59,898
Bob,

Craig and I never worked in the same office. His was at Petersen Publishing headquarters, then in Los Angeles, and mine was in my house in Montana. But we did have some interesting phone conversations!


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
IC B2

Joined: Jul 2001
Posts: 59,898
M
Campfire Kahuna
Offline
Campfire Kahuna
M
Joined: Jul 2001
Posts: 59,898
Ed,

Haven't developed a thumping routine, partly because (as I pointed out on at least one of the threads on the subject) it's difficult to separate the effects of thumping on the scope and mounts. Back in the 1990's the quasi-government German testing agency DEVA performed thumping tests on various scopes with a rubber mallet, which I reported in my first hunting-optics book OPTICS FOR THE HUNTER. But even they never attempted to separate whether the mallet affected the scope or the mounts.

However, over the decades I have observed that scopes more resistant to recoil also tend to be more resistant to accidental thumping--unless they're actually bent. Have seen that a few times, but even then most could still be used reliably after re-zeroing.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Joined: Sep 2005
Posts: 3,516
K
Campfire Tracker
Offline
Campfire Tracker
K
Joined: Sep 2005
Posts: 3,516
John,

Thanks for the article. I am a rifle loony and have been buying and selling rifles and scopes for the past several years. Always want to try the next thing. For now I have have found that a rifle that fits me and balances well for me in more important than the caliber or cartridge that the rifle is chambered for.With scopes, I tend to like fixed power scopes with duplex reticle and not over a 40-42 mm objective. I have taken a few range trips recently with several Leupold M8 friction adjustment scopes which were not exactly easy to sight in. What scopes would you recommend that have accurate adjustments for sighting in and then leaving them alone? I am not oppose to going with a variable scope if needed.

Thanks


“Go afield with a good attitude, with respect for the forest and fields in which you walk. Immerse yourself in the outdoor experience. It will cleanse your soul and make you a better person”
-Fred Bear
Joined: Jul 2001
Posts: 59,898
M
Campfire Kahuna
Offline
Campfire Kahuna
M
Joined: Jul 2001
Posts: 59,898
kandpand,

While fixed-power scopes aren't as common as they used to be, some are still being made--and I suspect more will show up in the future, not so much because of ruggedness but because more hunters are becoming aware of the advantages of a constant reticle size, especially with multi-point reticles.

It's too bad Burris doesn't offer their 6x40 anymore. It had click adjustments that were certainly consistent enough for a set-and-forget scope. However, the Burris 3-9x Fullfield II has equally good click adjustments, and is a great all-around set-and-forget scope, in my experience very reliable and tough.

Two fixed-power scopes that work pretty well are the 4x38 and 6x38 Weaver K's. Some people don't like the relatively short tube and eye relief of slightly over 3 inches in the 6x, because the combination can make the scope difficult to mount on some rifles. However, a rail-type base allows more mounting options, and I haven't found as much difficulty in mounting the 6x38 on long-action rifles as some other people have. (In my experience it works fine on short actions.)

The 4x38 has almost 3-1/2" of eye relief, so is more flexible in mounting. The only reticle available in both scopes is Weaver's version of a Duplex--a trademarked Leupold name--the Dual-X. Right now I have four of 'em, three 6x38's and one 4x38, and the adjustments are pretty good in all four. Dunno how much recoil they can take on a consistent basis, but they've worked fine on my rifles up to .30-06.

Another fixed-power option is the 6x42 SWFA, though it isn't available with a plex-type reticle. It's considerably bigger and heavier than the Weavers and is designed as a dialing scope, but doesn't cost much more than the Weavers. However, the adjustments are dead-nuts, it holds zero, eye relief is 3-1/2", and the long tube makes mounting easy.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Joined: Jan 2007
Posts: 131
J
Campfire Member
Offline
Campfire Member
J
Joined: Jan 2007
Posts: 131
I have a question about testing for light transmission through a scope. How do you test for it?

One thought I had was to have a consistent light source and use a photo light meter. You would measure the difference between the light at the front of the scope and the light as seen through the lens itself. Does seem like a valid, objective way to test for light transmission if you didn't have lab-grade testing equipment?

Joined: Jul 2001
Posts: 59,898
M
Campfire Kahuna
Offline
Campfire Kahuna
M
Joined: Jul 2001
Posts: 59,898
That doesn't work, because a typical light meter's sensor isn't large enough to measure all the light passing through a scope.

I described how test for light transmission (or "brightness") at the end of the article. It isn't as precise as using an integrating sphere, but correlates pretty well with the results from one.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
IC B3

Joined: Jul 2007
Posts: 499
O
Campfire Member
Offline
Campfire Member
O
Joined: Jul 2007
Posts: 499
I have a question regarding changes in scope construction over the years. What are the manufacturing difference(s) between a dialing scope and one that simply adjusts sufficiently accurately and holds zero.

I ask because you mentioned the box test that was usual in years past as opposed to more complex measures for testing dialing scopes, especially on the sameness of each click on the elevation axis. You also mentioned the swfa scope that is very inexpensive but is a good dialing scope. What is the difference in build that allows that inexpensive scope to do what so many other much more expensive scopes don't in terms of precise, repeatable adjustments?

Why, if building a rugged dialing scope need not be expensive, does this issue bedevil some very competent manufacturers of expensive scopes? Is there some tradeoff that's not obvious?

I'm also curious as to whether, in your opinion, the usual hunting scopes have increased, decreased, stayed the same in overall ability to retain zero in ordinary use since you began testing? What factors are correlated with failures? Larger objectives, parallax adjustments, target turrets, greater zoom range, higher scope weight, higher mounting height, maybe method of assembly- all these have changed from a time when a 3x9x32 was pretty typical for a hunting scope.

But, most of us probably have more guns and scopes in use. Are we seeing more failures because we use more stuff/ spend too much time on this forum/ generally bitch about prosperity?

Joined: Jul 2001
Posts: 59,898
M
Campfire Kahuna
Offline
Campfire Kahuna
M
Joined: Jul 2001
Posts: 59,898
The difference in consistent dialing scopes is basically tougher springs, and far fewer plastic or soft-metal parts in the turrets, erector tube, etc. Which is why effective dialing scopes typically weigh a lot more than typical "hunting" scopes: They're beefed up in the right areas.

That said, one reason the SWFA scopes are so reliable yet cost relatively little is they're sold directly to buyers on the Internet, rather than through the typical layers of wholesalers/distributors/retailers. Each of those layers needs to make a profit, so adds to the price to consumers. Plus, SWFA offers a number of fixed-power scopes, which can be made for less money than variables. Not nearly as many scope companies offer fixed scopes anymore.

It's my experience that more typical 1" hunting scopes are failing to retain zero these days, for a couple of reasons. First, there's increased competition in the marketplace. More of today's shooters own far more rifles that they used to in the decades after WWII, when scopes started becoming common on rifles. Back then most hunters had one big game rifle and, maybe a varmint rifle. Nowadays it's common for some hunters (especially the ones who frequent the Campfire) to own several rifles, and maybe several dozen. I've even seen posts where guys essentially brag about only having 4-5 rifles.

Most people think every rifle needs a scope these days, so they also buy more scopes. Many of these shooters spendd the same time shooting all of their many rifles that our grandfathers might have spent shooting 2 rifles, so many of their multiple rifles don't get shot all that much. This isn't because we don't want to shoot more, but many of us can't. Today about 85% of Americans live in urban areas, where just getting to a shooting range takes considerable effort.

Plus, we're often using smaller cartridges than our grandfathers used. Instead of one all-around .30-06, we have rifles for cartridges from, say, the .223 Remington to the 7mm-08, with maybe one .300 magnum. There's a big difference in recoil's effect on a scope between those smaller rounds and a .300 magnum, or even a .30-06 or 7mm magnum. Often we have these because another modern American trend is spending more time fiddling with our outdoor gear (including dreaming about buying more) than actually going out and using it, because of where we live.

Consequently, most scope manufacturers (or importers, which is far more often the case these days, when most optics companies order scopes instead of building them) know the vast majority of their scopes will go on relatively mild-recoiling rifles that won't shot all that much. This is why most claim even sub-$100 scopes are "recoil and shock proof." On the average deer rifle, shot a few times a year, they probably are--and even if they fail, so what? Replacing 3-5% of their scopes is cheaper than building truly recoil-proof scopes--and with so many optics companies out there today, price is a big competitive point. This also applies to "dialing scopes," because most shooters aren't going to dial them much.

Because most shooters don't really shoot much, especially hunters, they don't have much trouble with these scopes. But those who do shoot a lot have more scopes fail, especially on rifles that kick more than a .223, .243 or 7-08, particularly if they dial them a lot.

Right now I've had 17 different brands of scopes fail mechanically on rifles, some on relatively mild kickers. That's brands, not scopes; some brands have failed multiple times. This has happened far more in the past 20 years than before then.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Joined: Apr 2005
Posts: 30,811
J
Campfire 'Bwana
Offline
Campfire 'Bwana
J
Joined: Apr 2005
Posts: 30,811

Why do you recommend centering the reticle? Seems to me no matter where the reticle is located when one starts to zero his rifle the reticle is going to be in the same place when zeroed.

What am I missing.



I got banned on another web site for a debate that happened on this site. That's a first
Joined: Jul 2001
Posts: 59,898
M
Campfire Kahuna
Offline
Campfire Kahuna
M
Joined: Jul 2001
Posts: 59,898
I probably should have said "reticle/erector-tube assembly," rather than just "reticle."

In modern scopes the reticle is always centered in the optical view, but the reticle/erector tube assembly isn't always centered mechanically in the scope.

Moving the erector tube is what adjusts point of impact, so we want to mount the scope with the adjustments centered, so it has the the maximum amount of erector-tube movement. Primarily this is to prevent the scope from "running out of adjustment" when sighting-in, but also because the clicks tend to work most accurately when the erector tube's closer to the center of its adjustment range.

As a result, we need to start with the reticle/erector tube centered, and during mounting try to get it as closely aligned with the bore as possible without using the scope adjustments. This can be done with either a collimator or actual bore-sighting. Actual zeroing will normally still require a few clicks, but the scope will still be aligned closely to the bore, so there'll be plenty of adjustment left. (Of course, if you plan to use the scope only for longer-range shooting, it should be mounted tilted downward a little, the reason for slanted bases, or using Burris Signature rings. But the reticle/erector assembly should still be centered.)


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Joined: Apr 2005
Posts: 30,811
J
Campfire 'Bwana
Offline
Campfire 'Bwana
J
Joined: Apr 2005
Posts: 30,811


Once the mounts and rings are installed won’t the erector tube be where it sights in even if the erector tube isn’t centered before mounting. Will it change location if not centered before mounting?



I got banned on another web site for a debate that happened on this site. That's a first
Joined: Jul 2001
Posts: 59,898
M
Campfire Kahuna
Offline
Campfire Kahuna
M
Joined: Jul 2001
Posts: 59,898
You're not getting it. The mounting process needs to come close to aligning the scope with the bore WITH the reticle/erector tube centered. Much of the time, installing a scope in out-of-the-box mounts won't result in the scope being aligned, for several reasons, including an uneven top on the rifle action (not uncommon on factory rifles), bases that aren't machined precisely, and rings that also aren't aligned with the rings.

Add up all those factors and scopes will OFTEN be misaligned with the bore, even though there's still enough adjustment range in the scope to getting sighted in. Most people don't understand this, which is why many scopes don't adjust like desired. They may not anyway, but being mounted somewhat crooked doesn't help.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Joined: Apr 2005
Posts: 30,811
J
Campfire 'Bwana
Offline
Campfire 'Bwana
J
Joined: Apr 2005
Posts: 30,811
Originally Posted by Mule Deer
You're not getting it. The mounting process needs to come close to aligning the scope with the bore WITH the reticle/erector tube centered. Much of the time, installing a scope in out-of-the-box mounts won't result in the scope being aligned, for several reasons, including an uneven top on the rifle action (not uncommon on factory rifles), bases that aren't machined precisely, and rings that also aren't aligned with the rings.

Add up all those factors and scopes will OFTEN be misaligned with the bore, even though there's still enough adjustment range in the scope to getting sighted in. Most people don't understand this, which is why many scopes don't adjust like desired. They may not anyway, but being mounted somewhat crooked doesn't help.



Got you! Thanks.



I got banned on another web site for a debate that happened on this site. That's a first
Joined: Jan 2005
Posts: 22,884
D
Campfire Ranger
Offline
Campfire Ranger
D
Joined: Jan 2005
Posts: 22,884
So, how does one align the centered scope with the bore axis? What mounts allow for this type of adjustment besides the "standard" windage-adjustable type?

Joined: Jul 2001
Posts: 59,898
M
Campfire Kahuna
Offline
Campfire Kahuna
M
Joined: Jul 2001
Posts: 59,898
Burris Signature rings are probably the easiest way to get it done, but there are several other methods, including shimming both bases and inside rings. Talley will machine bases of their rings to fit off-kilter actions, and some gunsmiths regrind action-tops, or redrill mounting holes out to 8-40 to correct off-center 6-48 holes. It's also pretty easy for home gunsmiths to modify some bases and rings. I've written a number of magazine articles and book chapters about all of this over the years.

It's not rocket science, but a surprising number of scopes get blamed for running out of adjustment, or erratic adjustments, when the real problem is crooked mounting, including strain on the scope tube from crooked rings. Well, actually the rings may not be crooked, but the action they're mounted on is.

A number of shooters get irate whenever collimators ("bore-sighters") are mentioned, saying they've been sighting-in rifles for decades without one. But I've pointed out a number of times that the real value in a collimator isn't sighting-in, but making sure the scope is basically aligned with the bore when mounted. Many aren't.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Joined: Mar 2014
Posts: 159
P
Campfire Member
Offline
Campfire Member
P
Joined: Mar 2014
Posts: 159
Another great article John. I always learn something.

Do you have a favourite collimating that you could recommend?

Page 1 of 4 1 2 3 4

Moderated by  RickBin 

Link Copied to Clipboard
YB23

Who's Online Now
212 members (257 mag, 12344mag, 300jimmy, 10Glocks, 300_savage, 2UP, 21 invisible), 1,547 guests, and 881 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums81
Topics1,187,592
Posts18,397,917
Members73,815
Most Online11,491
Jul 7th, 2023


 







Fish & Game Departments | Solunar Tables | Mission Statement | Privacy Policy | Contact Us | DMCA
Hunting | Fishing | Camping | Backpacking | Reloading | Campfire Forums | Gear Shop
Copyright © 2000-2024 24hourcampfire.com, Inc. All Rights Reserved.
Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.3.33 Page Time: 0.126s Queries: 15 (0.005s) Memory: 0.9164 MB (Peak: 1.1048 MB) Data Comp: Zlib Server Time: 2024-03-28 10:15:06 UTC
Valid HTML 5 and Valid CSS