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Old April 11th, 2008, 11:20 AM #11
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herr.bear, preferred magnification depends on the target size and how much mirage I want to see.

For shooting small targets like varmints and bullseyes, I like at least 20x, and in the pic above, I'm using the scope at 26x. That's about on par with the LR benchrest guys, who run 24x to 36x on the average. This higher magnification allows me to see mid-range mirage better, which is often the only wind indicator available on a nice summer afternoon. It often allows me to tell whether that tan lump on the edge of the hay at longer ranges is a groundhog head or a tuft of grass. It also allows me to mark my misses myself and so if a second round correction is needed, it's more reliable and quite fast.

My two LR tac comp rifles have 22x max, but more so for precise target measurements with the (mil) reticle graduations (for accurate ranging) than to see/hit the target itself. The better you can see, the more accurately you can measure reticle subtension/target size, the better you can measure, the closer your distance calculations will be, the accurate your distance calcs, the fewer targets are lost due to range estimation errors. Targets themselves at the tac comps are usually 1 to 2 moa in size, and a 10x scope provides plenty of magnification to put the crosshairs on the target this size at 1k. A "1 moa" target at 1,000 yards is about 10-1/2", "2 moa" is close to 21".

The greater magnifications provide a better view, but also show more mirage, which can be good or bad, depending on whether it's just boiling and you want to shoot through it or if you'd like to see it better to use for gauging a light wind. This is why I prefer variables, and if mirage is so great it makes target focus tough, I'll reduce magnification a little to make it less pronounced
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Old April 11th, 2008, 11:40 AM #12
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Thanks... great write up. Always a learning experience when I read them. Now I just need to get out and practice.
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Old April 11th, 2008, 11:44 AM #13
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i think my only chance to drive to the middle of a large field and shoot from the back of my truck would be if my gf inherited the family farm down in calvert. be a heck of a good time. and the truck would make changing targets much faster as well
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Old April 13th, 2008, 12:17 AM #14
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Ed,at 900 yds,on a good day,what would a good 5 shot group measure?
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Old April 13th, 2008, 01:38 AM #15
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900 yards! A regular Bob the Nailer.
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Old April 13th, 2008, 07:37 AM #16
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Quote:
Originally Posted by Jimet View Post
Ed,at 900 yds,on a good day,what would a good 5 shot group measure?
With the emphasis on "a GOOD day" (no wind, mirage or caffeine) that rifle will shoot to about 3" at 900. It shoots a Sierra 140 at about 3,400 fps or a Lapua 123 Scenar at a little over 3,500, both into about 1/4 moa. My tac rifles shoot closer to 3/8 moa and on the same day will shoot a 4" or larger group at that same range.

With rifle technology these days, atmospheric conditions and the shooter are the limiting factors and in 1k BR, IIRC the current record is less than 1-3/4" for 5 shots.

Houserocker, we can get to 1,200 at that same farm if we juggle our positions a little, we go to 1,030 at Quantico every time we shoot, and some of the tac matches present targets at near 1,400. It's all relative to target size, and one could shoot barns at 900 with even a lever gun . . . In that pic above, we're load testing and getting data, for the very longest shots mentioned, we shooting steel plates that run about 1 moa or a little bigger. At the Allegheny Sniper Challenge last year, the toughest target was a LaRue popper (1/2 moa wide) at 1200 in a good cross breeze.
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Old April 13th, 2008, 09:38 AM #17
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I have to thank you Ed, you've got me started on a life-long addiction with the LR bolt guns , the one I told you about has just started construction, I'm thinking maybe by mid-summer I should have it back and ready to go
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Old April 13th, 2008, 10:39 AM #18
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At what distance does "long range" become official? On a box of .22s is a warning that the bullet can travel over a mile but I don't consider a .22 a LR rifle,now,a 22-250 is another story.
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Old April 13th, 2008, 11:54 AM #19
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You're welcome Tundra . . . give a holler when you're ready to hit Quantico one day.

Good question Jim . . . and the answer is dependent on the outfit used, the target size and the desired effect. We could assume sufficient terminal energy and a "reasonable" sized target . . .

While a .22 Rimfire (RF) slug will/may carry to more than a mile (1,760 yards) downrange, and an efficient center-fire (CF) can go 3 miles or more when fired at an optimum elevation angle (usually 25 to 35 degrees above horizontal) and constitute grave danger, actually intentionally hitting something is not likely at half or even one quarter of these distances.

Given a "good" hit probability (75% (3 out of 4) or better?), the ranges we'd consider "long" shorten considerably. Obviously, what would be rightfully considered a "long shot" with an off the shelf sporter class rifle may not be such a big deal with a match grade heavy gun. A big advantage to long range shooting is the ability to shoot a bullet of high ballistic coefficient (BC) to minimize flight time/drop and help negate wind variations, the single biggest player.

Admittedly very subjective, and just *MHO*: True "Long Range" with an accurate rig is where we start to be challenged by more than just how steady we can hold, I suggest we're in the following zones for these examples:

.22 RF: 150 plus yards

CF small caliber/slow twist/light bullet (55 grain/.22-250, 75/.243, 150/.308 class): 400 plus

CF small-med caliber/fast twist/heavy bullet (77-80 grain .223, 105/.243, 168/.308): 700 plus

CF med caliber fast twist/heavy bullet (115/.243, 140/.264, 175/.308): 900 plus

CF med-large caliber specialty fast twist/heavy bullet (210/.300WinMag, 300/.338 Lapua, 400/.408Cheytac, etc.) 1,200 plus

CF BIG stuff (.50BMG & variants, .20mm) 1,500 plus . . . The BMG and 20 are theoretically superior in a ballistic sense, and resist atmospheric problems better than almost everything else, but are usually not as accurate as the other slightly smaller calibers and "hit probability" drops. If you can't land one where it needs to go, who cares what you're tossing or how efficient it is?

Knowing exactly how far is key to any long range capability, and the effective range of almost any caliber can be increased by knowing the **exact** distance to the target.

For example, a 175 .308 drops almost 2 moa in the scant 30 yards between the 1,000 yard target frames at Quantico and the berm at 1,030. So, missing your range estimate with this combo by more than a few yards can cause a miss of Biblical proportions . . . I once made the mistake of shooting sighters on the berm with my LTR, then moving to the paper target frame for record fire w/o bringing my elevation setting down. My bullets were off the top of the frame. . . Since they dropped behind the target before striking the berm, they just seemed to disappear, causing a bit of a panic, LOL.

Target character plays an important role. We shoot steel plates *much* further that what would be a sure, humane shot at live game like a deer. We often find unexpanded bullets on the ground around the target stands at ranges exceeding 1k, meaning they might not even open up, and with more than a full second flight time to 1k, almost anything can happen before the bullet arrives.
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Old April 13th, 2008, 12:54 PM #20
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At 900 yards, I would have to send it in a brown truck!
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