Hey all,
This is my first post here, I've been lurking for a couple of years and am sifting through scope options for a few different rifles. This got me wondering as to the usefulness of certain scope configurations for various roles. I'm looking for one, a lightweight AR "recce" type rifle for 1-500 yard effectiveness, and two, a lightweight .300win mag for moose hunting out to 300-400 yards, and also the ability to stretch the legs of the .300 tactically, out to 900-1000 yards.
It seems that both of these rifles are somewhat hybridized, in that it can ask a lot of an optic to excel at multiple things well. The AR, being a tactical type rifle, that could be used under stress in a non-bench rest setting (i.e. running, rollover prone, slung etc.) the most important thing is shouldering the rifle and instantly acquiring a proper sight picture (which of course is the sole purpose of CQB sights). And the .300 win, at dusk, 400 yards away a dark colored moose moving into a tree line, low light performance is critical, if you can even see the reticle against the shadows.
Am I right in assuming that a scope's ability to work well in challenging environments like these is directly related to Exit Pupil size? I've heard mention of scopes like the 1.5-6x42 config being "easy to get behind" and having forgiving "eye boxes".
So, for the AR, engaging a man-sized target at 300 yards would be most comfortable at lets say around 4x-9x. So, with an objective of 42mm, at 6x we'd have our full 7mm exit pupil. My question is then, at 3x would we have twice the room for error when shouldering the rifle, or half the room for error at 12x? (and also much less image brightness) I read Chuck Hawks say once, when referring to the now discontinued Sightron SIII 1.5-6x50, that the 50mm objective was wasted because even at full 6x, only 42mm was needed to reach the magic 7mm human pupil size. Also, i began wondering, if you have a 7mm human pupil being bathed by an image with a 33mm exit pupil,such as on the Sightron at 1.5x, if the image isn't centered up, such our pupil being clear to the edge of the image, does this induce parallax error? Or is this the"very forgiving eye box " I've heard about? Also, how does eye relief "range" come into play? So, I guess in essence I'd like to know more about the physics involved, and what would make a tactical carbine/recce rifle easy to get behind under stress, and a longer range scope cranked up to 9x or 14x and have good lowlight performance and eye placement forgive-ability without having a larger than a 50 or 56mm objective. I've got to place some kind of weight restriction for both of these scopes and their roles, and I think 24 oz is about max. Is this a boring and useless topic or thought provoking? I love this forum! Thanks guys! Curt
This is my first post here, I've been lurking for a couple of years and am sifting through scope options for a few different rifles. This got me wondering as to the usefulness of certain scope configurations for various roles. I'm looking for one, a lightweight AR "recce" type rifle for 1-500 yard effectiveness, and two, a lightweight .300win mag for moose hunting out to 300-400 yards, and also the ability to stretch the legs of the .300 tactically, out to 900-1000 yards.
It seems that both of these rifles are somewhat hybridized, in that it can ask a lot of an optic to excel at multiple things well. The AR, being a tactical type rifle, that could be used under stress in a non-bench rest setting (i.e. running, rollover prone, slung etc.) the most important thing is shouldering the rifle and instantly acquiring a proper sight picture (which of course is the sole purpose of CQB sights). And the .300 win, at dusk, 400 yards away a dark colored moose moving into a tree line, low light performance is critical, if you can even see the reticle against the shadows.
Am I right in assuming that a scope's ability to work well in challenging environments like these is directly related to Exit Pupil size? I've heard mention of scopes like the 1.5-6x42 config being "easy to get behind" and having forgiving "eye boxes".
So, for the AR, engaging a man-sized target at 300 yards would be most comfortable at lets say around 4x-9x. So, with an objective of 42mm, at 6x we'd have our full 7mm exit pupil. My question is then, at 3x would we have twice the room for error when shouldering the rifle, or half the room for error at 12x? (and also much less image brightness) I read Chuck Hawks say once, when referring to the now discontinued Sightron SIII 1.5-6x50, that the 50mm objective was wasted because even at full 6x, only 42mm was needed to reach the magic 7mm human pupil size. Also, i began wondering, if you have a 7mm human pupil being bathed by an image with a 33mm exit pupil,such as on the Sightron at 1.5x, if the image isn't centered up, such our pupil being clear to the edge of the image, does this induce parallax error? Or is this the"very forgiving eye box " I've heard about? Also, how does eye relief "range" come into play? So, I guess in essence I'd like to know more about the physics involved, and what would make a tactical carbine/recce rifle easy to get behind under stress, and a longer range scope cranked up to 9x or 14x and have good lowlight performance and eye placement forgive-ability without having a larger than a 50 or 56mm objective. I've got to place some kind of weight restriction for both of these scopes and their roles, and I think 24 oz is about max. Is this a boring and useless topic or thought provoking? I love this forum! Thanks guys! Curt
