Bringing back detachable iron sights
- Thread starter User00040
- Start date
Sambarrmann
Active Member
Hi Scrumbag,
sorry I didn't get back earlier - maybe I missed seeing your last post about my book. I don't know what other stuff I sent with your copy but the story moves on. There's a gunsmith here who wrote a book on precision rifle shooting; he goes to so much trouble getting image-movement scopes straight and not to bend them that it seems to me he could spend less time mounting a reticle-movement scope properly (if only because he would not have to twiddle the knobs while turning the scope through 360 degrees just to get the reticle centred).
Considering how much time many shooters spend preparing cases when reloading ammo, I'm damned if I can understand why they would not spend a few more minutes mounting their scopes. Had serious shooters known 60 years ago the BS concept got up just to capture the lowest common denominator of lazy people, a few more might have thumbed their noses at it. For 50 years I assumed image-movement centred the reticle the Pecar Champion way and just put a restrictive field stop around it. While that is silly enough and also gives small fields of view and tunnel vision, at least it doesn't suspend the entire guts of the scope on a spring.
Cheers
- Paul
sorry I didn't get back earlier - maybe I missed seeing your last post about my book. I don't know what other stuff I sent with your copy but the story moves on. There's a gunsmith here who wrote a book on precision rifle shooting; he goes to so much trouble getting image-movement scopes straight and not to bend them that it seems to me he could spend less time mounting a reticle-movement scope properly (if only because he would not have to twiddle the knobs while turning the scope through 360 degrees just to get the reticle centred).
Considering how much time many shooters spend preparing cases when reloading ammo, I'm damned if I can understand why they would not spend a few more minutes mounting their scopes. Had serious shooters known 60 years ago the BS concept got up just to capture the lowest common denominator of lazy people, a few more might have thumbed their noses at it. For 50 years I assumed image-movement centred the reticle the Pecar Champion way and just put a restrictive field stop around it. While that is silly enough and also gives small fields of view and tunnel vision, at least it doesn't suspend the entire guts of the scope on a spring.
Cheers
- Paul
Sambarrmann
Active Member
Furthermore, Scrummy,
I don't suppose the book I sent you dated from after I discovered there were a couple of mistakes in the table on p119 and that those mistakes had caused me to draw a wrong conclusion on the difference in 'excess hidden field' (tunnel vision) between old scopes and modern image-movement ones. So, instead of the modern ones only having about 10% more excess hidden field (measured horizonally cf field of view) the correct figures showed they were in fact more than 25% worse than old reticle-movement and B&L scopes. Though modern, fat-rubber eyepieces were part of the reason, two of the old scopes also showed some tunnel vision from rubber eyepieces. Also, one of the image-movement scopes had a metal eyepiece on an 'egg-shaped' ocular that tapered in order to overcome that problem, even though the field stop still reduced the Nikko-Stirling Silver Crown's 4x FoV to 23 feet. That 23 feet at 100 yards made the FoV more than 20% worse than the once-usual 30 feet and maybe 35% worse than the pre-65 Leupold scopes, though the Leupies did have an eyepiece about 10% wider.
Combining those humble discoveries with information from a former Californian film-industry technician, and an admission from Burris in a promotional video for Signature rings, has led me to believe that constrictive field stops are not just to remind us that the reticle is constantly centred but to mask reflections from the walls of the erector tube when it is set crookedly in the outer tube to compensate for poor mounting.
At high powers this stuff may not matter much because magnification has already obliterated acres of FoV -- but it is vital to anyone who hunts dangerous or wary game with a scope set at 1x or even 2.5x. If you are aiming at a buffalo you don't want the possibility of another herd member charging out of the tunnel of hidden landscape created by the field stop and rubber eyepiece. Though these tunnels can occur in either reticle system they are, as found in my little experiments, much worse in modern scopes. As an example, my old Nickel Marburg 1-4x21 had an excess hidden field of 5.8 feet at 1x while my son's Kahles Helia C 1.1-4x has 29.7 ft (shown in the new table) at 1.1x. Even with the rubber removed from the Kahles it still has 17.5 ft excess hidden field, enough to hide a belligerent beastie at any more than 20 yards. My favorite little scope is the ancient Nickel Supralyt 1x12 shown on the back cover of the book. Though I made two calculations for that scope, the photo suggests Colin Shadbolt's Nickel table may have been correct and that the total hidden field was as little as one foot (the sum miraculously showed 304mm
).
Let me know if you'd like me to email you a copy of this new stuff.
I don't suppose the book I sent you dated from after I discovered there were a couple of mistakes in the table on p119 and that those mistakes had caused me to draw a wrong conclusion on the difference in 'excess hidden field' (tunnel vision) between old scopes and modern image-movement ones. So, instead of the modern ones only having about 10% more excess hidden field (measured horizonally cf field of view) the correct figures showed they were in fact more than 25% worse than old reticle-movement and B&L scopes. Though modern, fat-rubber eyepieces were part of the reason, two of the old scopes also showed some tunnel vision from rubber eyepieces. Also, one of the image-movement scopes had a metal eyepiece on an 'egg-shaped' ocular that tapered in order to overcome that problem, even though the field stop still reduced the Nikko-Stirling Silver Crown's 4x FoV to 23 feet. That 23 feet at 100 yards made the FoV more than 20% worse than the once-usual 30 feet and maybe 35% worse than the pre-65 Leupold scopes, though the Leupies did have an eyepiece about 10% wider.
Combining those humble discoveries with information from a former Californian film-industry technician, and an admission from Burris in a promotional video for Signature rings, has led me to believe that constrictive field stops are not just to remind us that the reticle is constantly centred but to mask reflections from the walls of the erector tube when it is set crookedly in the outer tube to compensate for poor mounting.
At high powers this stuff may not matter much because magnification has already obliterated acres of FoV -- but it is vital to anyone who hunts dangerous or wary game with a scope set at 1x or even 2.5x. If you are aiming at a buffalo you don't want the possibility of another herd member charging out of the tunnel of hidden landscape created by the field stop and rubber eyepiece. Though these tunnels can occur in either reticle system they are, as found in my little experiments, much worse in modern scopes. As an example, my old Nickel Marburg 1-4x21 had an excess hidden field of 5.8 feet at 1x while my son's Kahles Helia C 1.1-4x has 29.7 ft (shown in the new table) at 1.1x. Even with the rubber removed from the Kahles it still has 17.5 ft excess hidden field, enough to hide a belligerent beastie at any more than 20 yards. My favorite little scope is the ancient Nickel Supralyt 1x12 shown on the back cover of the book. Though I made two calculations for that scope, the photo suggests Colin Shadbolt's Nickel table may have been correct and that the total hidden field was as little as one foot (the sum miraculously showed 304mm
).Let me know if you'd like me to email you a copy of this new stuff.
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