This past weekend I shot in the rain-shortened 1000 yard match. I wanted to get some rounds downrange to verify the setup before the state match in a couple of weeks.
As it turned out the elevation was dead on, as expected and windage was a bit off, but that understandable as I did not put the other scope back to "no wind" zero before shooting the two rounds on the tall target, and the wind on Sunday was fairly intense and if the other direction from the settings. Nevertheless, I was in the black in a couple of shots and shooting 10s and Xs until I started shooting for record. After my initial X, one-on, the wind just kept up a crazy dance ahead of the big Texas rainstorm that dumped on us a little later.
I did notice that I could see the reticle quite clearly and I'm very happy with the decision to change the reticle and the selection I made.
Next up, I will be discussing reticles on this thread.
Thanks for all the great info. I have a question.. I'm probably going to purchase a 17HMR if I can ever decide what rifle to buy.. cz, ruger, Savage. etc. Then will come a scope. I'm looking to shoot "whistle pigs", ground squirrels at 100 yds or less. So I'll have to come up wit something.. That's the background.. but the question comes from different types of scopes. I'm told that I need to purchase a specific type.. ie.. a scope for rimless cartridges.
What is the difference between standard scopes and those built for rimless?
I think you mean rimfire and not rimless.
I'll give a longer answer tomorrow when I get to a real computer. There's not much difference but usually scopes for rimfires have their parallax set closer than regular scopes.
Yep, rimfire.. not rimless..
I had a brain fart.
I get them all the time, don't fret it.
When I bought my first 22LR rifle, I also bought my first scope and it was a Bushnell made for a rimfire. In those days the scope mount designs were varied and this scope use a dovetail mount.
It also had a 3/4 inch tube, no objective bell and 2-7X zoom range, if I remember correctly. (It's long gone, this was almost 45 years ago. I still have the rifle, a Ruger 10/22.)
Nowadays, the rimfire scopes, such as those from Leupold, a one inch tube and are just as good as their centerfire equivalents, but the parallax adjustment is usually at 60 yards instead of the more common 100 to 150 yards of their centerfire brethrens. Of course, if you get a scope with an adjustable objective then you won't have to worry about that.
Recently, I installed my Nightforce NXS 12-42X56 on my Ruger 10/22 and took it to a local rimfire benchrest competition. This is when I discovered 2 things. 1- The minimum focus on the nightforce is way further than I expected and 2- The point of aim shifted by about an inch between 12X and 42X; shocking.
However, for your purposes with a 17HMR, you do not need or want a rimfire scope; you want a normal scope with the parallax set further out than on a rimfire scope, or better yet, you want an adjustable objective.
Thanks for that great information.
"However, for your purposes with a 17HMR, you do not need or want a rimfire scope; you want a normal scope with the parallax set further out than on a rimfire scope, or better yet, you want an adjustable objective."
Do you have any suggestions? I don't want to spend an arm or a leg.. but I'd like a variable that would be on the order of 5-25 or thereabouts with a good light gathering objective that might go for less than $250 at a discount store.
I remember seeing some of what I thought might be decent buys on Leupold and Nikon.. but, can't remember the specs ATM.
I would suggest you start your own thread and ask for help in selecting a scope for your purposes. As you might have gathered by my writings, my predilection tends towards long range competition shooting, or target shooting, not hunting at short range.
There are many scopesight options that will permit focusing at close distances for use with rimfire rifles, etc. I have a Leupold “EFR” 6.5-20× scope that can be focused as closely as about 10 yards, and I use it for certain practice. Other current extended focus range sights by Leupold and other manufacturers will also focus about that closely. That, however, may actually not be necessary if the hunter doesn’t anticipate close range shots. If you don’t anticipate shots closer than 50 yards, for example, many other scopesights will be usable. On the other hand, I like to anticipate the other things I might do with a gun and sight combination, so I would be happy with the flexibility that sight gives me on my Ruger 77/22 even if I didn’t have a specific purpose for close focus now.
And yes, I agree with the suggestion about a separate thread. Ironically, these stickied topics seem to get less attention than the new ones.
The one other bit of advice I’ll offer, though, is that if close focus is possible with a side mounted knob rather than an adjustable objective (AO), you will probably find that more suitable for hunting. The AO is usable, but not nearly as fast and convenient as the side focus adjustment. The one I have works fine for target practice, but would not be very good for hunting at different, constantly-changing ranges.
“I can’t give you brains, but I can give you a diploma.”
— The Wizard of Oz
Speaking of side focus (SF) vs. adjustable objective (AO), (yeah you got me started.) It should be stated that the AO design is simpler and more precise than the SF method. The AO very much functions like a regular telescope or camera lens by actually focusing the objective lens group onto the first focal plane at the front of the erector tube. That's a simple process and it's very precise and you can easily make small focus adjustments. The downside is that the focus is at the front of the riflescope and as sigfreund says that is not easy to reach while hunting but it's great for target or competition shooting at known distances.
The SF method actually involves another lens assembly in front of the first focal plane and that is used to alter the image coming from the objective lens assembly; in other words it's not a pure focus, it's an adjustment behind the objective lens assembly. It is not as crisp as the AO and it involves more lenses. On the other hand, it's very handy and I've really taken to if with my current March scope with the addition of a large focus wheel that allows me to easily fine-tune the focus. It also allows me to change the focus to various distances to look at the mirage at these distances and then snap back to the target line when ready to shoot.
Thanks.. just returned from a trip.. now to try to dig into this....
While at SHOT 2020, I spent quite a bit of time talking with the chief designed of the March scopes, through an interpreter, of course. Also, he carries documents with him at all times, and he draws really well.
I should point out that before he founded March with other engineers, he was at LOW and designed many scopes with which people here are very familiar.
These guys started their own company to make the scopes they wanted to make, without the constraints imposed my bigger outfits and bean counters.
So over the next several posts here, I'm going to talk about some of the stuff I found out, without going into stuff that may be proprietary.
The first item I want to discuss is the gas used in the scope. As most of you know, high end scopes are sealed against water and air. They are usually filled with nitrogen. (I was a bio-chemistry major back in my university days, 40+ years ago.) As you know nitrogen makes up about 70-some% of the atmosphere. Towards the end of the assembly process, the air in the scope is replaced with nitrogen to prevent fogging and other nasty things and the pressure is equivalent to sea level. The O-rings are inserted and the scope is now sealed with no oxygen or water vapor in it. March does not use nitrogen to fill the scope, they selected argon instead. The reason for that is that argon is a noble gas, completely inert and the argon molecule is twice the diameter of the N2 molecule and so it has less tendency to leak out and over time the argon stays in the scope longer than the nitrogen. Argon makes up about 1% of the atmosphere.
March did not invent argon filled optics, but it seems only very high end optics are argon-filled. Interestingly enough, my triple-pane windows at the house are argon filled. I guess that explains some of the exorbitant cost. They have been installed for over 14 years now and they are still very clear. I know that racing tires are filled with nitrogen now, and that's to replace the air which may have moisture in it. But you do have to keep an eye on the pressure and replenish as needed. Maybe argon-filled tires?
Next up I will discuss the innards of scopes.
|fugitive from reality|
Part of the reason why nitrogen is used in automotive applications is a single gas has a constant expansion rate. Air as we know it is 78% nitrogen, but the remaining gases can vary enough to make expansion under heat and pressure inconsistent.
'I'm pretty fly for a white guy'.
Probably the singlemost important piece inside a riflescope is the objective lens group. Notice that I say group, not lens. Indeed the big lens in front is part of a doublet, a pair of lenses.
In the March scopes with ED or Super-ED lenses, the lenses made of the material are the two lenses in the objective lens group. I suspect that is the same for other riflescopes.
The reason you want those two lenses to be the ED/Super-ED (low dispersion glass) lenses is because those are the ones that bend the light the most and bending the light is what generates chromatic aberration in a optics. An objective lens of 56mm will bend the light to produce an image of itself that will fit in 26mm or less, whatever the ID of the main tube is at the first focal plane.
The objective lens group receives the light from the objective (target) and scrunches it down to fit on the FFP. If the objective lens group produces a bad image, there's no way it can be improved from there, which is why that lens group is so critical to have as near-perfect as possible.
Now some would think that you want ED/Super-ED glass in all the lenses of a riflescope. In reality, you don't want that, for two reasons.
A) Cost. These lenses cost significantly more than low dispersion glass lenses.
B) Light transmission. Low dispersion glass lenses have the lowest refraction index of optical glass because of the fact the material reduces or eliminates some of the sidebands from the various colors coming through. That's what helps reduce or eliminate CA. So with the low refraction index of the objective lenses, you want to preserve as much as possible the light that does come in and so you use high refraction index glass after the objective lens.
So a high quality high magnification riflescope will have expensive low dispersion glass ($$$$) for the objective lens group and high refraction index ($$$) glass everywhere else.
For scopes that have small objectives compared to the main tube, you will find that they do not have, or need, low dispersion glass in the objective lenses; it would be a waste of expensive glass.
On the other hand, the use of low dispersion glass has allowed the construction of riflescopes with big objective lenses but that remain very short. They bend the light a lot, but the low dispersion glass controls the CA.
For instance at the March booth, we were showing a 4.5-28X52, that is only 12 inches long. That front part is short, but the IQ is superb. There was also a 5-42X56 that's only 14 inches. In comparison, my 5-50X56 with ED glass is 15.7 inches long. The 5-42X56 has Super-ED glass, which allows it to be almost 2 inches shorter and still have as good or better IQ.
Let’s talk about weight.
One of the things that struck me about my March-X 5-50X56 was the fact it was 30 ounces, compared to 38 ounces for my Nightforce NXS 12-42X56. I appreciated the half pound weight saving, as F-TR rifles have a weight limit which includes the scope and the bipod. (Yes, I have a JOYpod, one of the lightest bipods around.) So saving a half pound on the scope meant that it could put that in my barrel.
But why was the March-X lighter than the NXS, with similar dimensions and specs? The obvious first though is that the Nighforce is built tougher that the March-X, that it has thicker wall material and so on. Closer examination shows this to be incorrect, grossly so. The March-X has a 34mm tube compared to the 30mm tube of the NXS. Well, people immediately think that the wall thickness is the same and that the March-X has a wider adjustment range because the tube is 4mm wider. The reality is that the March-X has a tube with walls that are 4mm thick compared to the 2mm walls of the NXS, or indeed, every Nightforce scope as far as I know. The March-X has 4mm thick walls which accounts for the difference in the tube size (34mm, 2mm extra per side). This makes the March-X immensely strong. Stronger than any other scope out there.
I spent quite a bit of time talking optics and the mechanics of a March scope with the chief engineer at SHOT, after hours as we were deluged with visitors. I found out quite a bit more about the scopes and I must say, I am super impressed with March. I think I already mentioned that each and every scope body starts as an ingot of aluminum bar stock and it is machined completely. There is not extrusion or forming or molding of any kind, unlike most other scopes. The 30mm March scopes have 2mm walls like the Nightforces, the 34mm tubes have 4mm tubes, unlike anyone else; but both the 30s and the 34s are completely machine from a billet.
So I asked the chief engineer how is it that my March-X is 8 ounces lighter than my NXS and yet had walls that are twice as thick? How is that even possible? That led to a great discussion which involved drawings on the back of a napkin. The gist of it is that it's all down to engineering. The guy who had done the design was in his element here; I had asked the exact right question, right up his alley and he was proud of his design.
Lenses make up the bulk of the weight, especially ED and Super-ED lenses. Next, the scope body is the single heaviest part, and we know that the March-X scope body is about double the weight of the NXS scope body. Later in my room, I made a quick calculation of the approximate weight of the scope body of the March-X and came up with about 296 grams. If the wall had been 2mm thick, my estimate was 150g.
The total weight of the March-X is 870g. That leaves 574g for the rest. We are talking about a doublet of ED glass at 56mm diameter, a focusing lens in the cone, the erector prism, the 3 zoom lenses with a diameter of about 25mm each, the reticle and the eyepiece assembly. That’s a lot of glass. My estimate is about 350g of glass leaving about 225g for the other inner parts and the knobs and such, about a half pound.
He has designed each and every part that goes in a March riflescope and over-engineered them to make them as strong as possible without unnecessary weight and bulk. So the weight savings were not because of one part, it was the accumulation of weight savings for a hundred plus parts. In a riflescope, there are 150 parts and then were all designed to be as strong as possible and yet light.
To my mind, having light but strong parts on the inside actually enhances the overall strength of the design, where the goal is to keep the zero on the scope. If you understand how a scope works, there is an inner tube that goes up and down and side to side, as you turn the knobs. Opposite of the knobs there are springs or some form of flexible yet firm resistance that pushes the inner tube against the knob, but that can yield to allow the inner tube to be adjusted. A heavier inner tube will exert more force against the knobs and “springs” during recoil or a fall or some type of impact. This helps explain why March scopes are legendary in their holding zero.
Yes, I asked about the “springs”, and he was a little reluctant to discuss them in detail and I understand why; the design is genius. Suffice to say, they don’t take a set. There’s a reason I use scare quotes around the word “spring”.
So when March says that all the parts in their scopes are made in Japan, they are probably made to their exact specifications or they make them themselves like they do for the scope bodies.
It was very educational and also a lot of fun talking with the chief engineer. I felt a bit like a kid in an candy store; ok, a lot like that.
In the meantime, I acquired another March scope, this time a March-X 10-60X56HM, which is very similar to my existing 5-50X56 but this one has Super-ED glass for even better CA control. I have assembled it in its rings and mounted it on a rail. I hope to sight it in on my match F-TR rifle this weekend. I’ll post some pictures soon.
Here is a picture of the new setup
You can see the Burris XTR Signature Rings, the Tubb level and of course, the March-X 10-60X56HM scope with added zoom lever, large focus wheel and sunshade.
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