Rifle Scopes hmmmm.... @100 dead on..@400 .5mil left @660y 1mil left
- Thread starter Ring
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Based on your observations, the relationship between range and change on POI doesn't correlate. It appears to be a variable that changes with a non-linear relationship to range?
Variable power scope?
If so, were you at the same magnification for all 3 ranges?
First or second focal plane?
Was parallax accounted for at all 3 ranges?
Also, did all the shots at 400 and 660 show the same horizontal deviation?
Variable power scope?
If so, were you at the same magnification for all 3 ranges?
First or second focal plane?
Was parallax accounted for at all 3 ranges?
Also, did all the shots at 400 and 660 show the same horizontal deviation?
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The first thing that comes to mind is the rifle is canted. B Litz has an interesting article about it. The human eye can only detect about 3 degrees one degree = about 12" at 1k. I would go through and remount the scope, bubble level etc, especially if the rifle is grouping well.
Shooting a 10" plate... Gun has been away all winter.. Didnt shoot that way last summer...
Sniper match next Sunday... Not many days left to work out the bugs
Prone....
Sniper match next Sunday... Not many days left to work out the bugs
Prone....
How do you know the wind was 0-3mph, and what direction was it pushing when it was 3mph?
1mil left at 660 would be a good bit of wind, unless this is a 55gr from a 223, but nevertheless, wind can be feisty, especially a few yards above the ground.
It isn't spin drift, because spin drift would most likely push bullet right (if the twist is to the right) and only by 0.1mil at 660.
Like others have said, remount and make sure its level. And then reshoot.
1mil left at 660 would be a good bit of wind, unless this is a 55gr from a 223, but nevertheless, wind can be feisty, especially a few yards above the ground.
It isn't spin drift, because spin drift would most likely push bullet right (if the twist is to the right) and only by 0.1mil at 660.
Like others have said, remount and make sure its level. And then reshoot.
Is it possible your Natural point of aim was off a little.I know the position of your left elbow can have a big effect on natural point of aim.
Regards,Mike
Regards,Mike
shooter and mid range.. last 100y to target was wind blocked by trees... even local weather station showed max gust for the day @ 3mph for it to be wind, it would have had to be a 10mph wind.. i would have noticed that
I have been noticing a trend of missing to the right with my rifle at extended ranges... after reading this I will go ahead and check to make sure everything is plumb and level.
These threads crack me up, it's like the worst game of "telephone' on the planet.
Spin Drift going the opposite direction, hey don't sweat it I like to use SD as an excuse too... makes you sound, worldly. It's one of my top 14 excuses.
A Foot of deviation from 1 degree of cant, ya that has to be right, he quoted someone smart. Forget the tolerances on scopes are 3 degrees or less when assembling the reticles, if they (manufacturers) can't hold less, I am sure we can, easily. Those 1/2" levels are the cat's ass, the company that makes them said so. I mean they wouldn't sell it if I didn't absolutely need it. Only problem, isn't 1 mil of offset 21.6" at 600 yards... oops, maybe it was that 3 degrees.
Phantom Winds not checked at the target, because certainly a 260 shooting a 142gr needs to have everything accounted for inside 600 yards, shooter, mid range and target. After all a 10MPH wind at 600 with a 142 is in fact a 1 Mil adjustment. And we all use 10. Big difference if you screwed that up, cause if you checked at shooter and it is 3MPH plus mid range and you missed checking the target and it 10MPH, big miss. That is .7 seconds versus what might be .3 seconds at 300 yards, that .3 seconds gives the wind an awesome amount of time to work on the bullet, pushing off. Then again, a 2 MPH (Let's assume a mistake of that magnitude) is .2 mils with that 142gr bullet at 600 yards. I mean the bullet slowed down right.
No, these threads are my favorite to read, all the anecdotal evidence, the 3 hand data, so valuable many suggestions.
Personally I think the barrel warped at the last few inches where it sat in the safe, that, or it was lunar drift as we have had a rather large Moon effecting the Earth's gravity over the past few weeks. Lunar Drift is often overlooked, and combined with Coriolis can easily cause a miss, that is excuse #7 ... I would check Space.com for any asteroid or comet sightings, any reports of Alien UFO activity in the area, they use magnetic propulsion which can move the bullet.
Spin Drift going the opposite direction, hey don't sweat it I like to use SD as an excuse too... makes you sound, worldly. It's one of my top 14 excuses.
A Foot of deviation from 1 degree of cant, ya that has to be right, he quoted someone smart. Forget the tolerances on scopes are 3 degrees or less when assembling the reticles, if they (manufacturers) can't hold less, I am sure we can, easily. Those 1/2" levels are the cat's ass, the company that makes them said so. I mean they wouldn't sell it if I didn't absolutely need it. Only problem, isn't 1 mil of offset 21.6" at 600 yards... oops, maybe it was that 3 degrees.
Phantom Winds not checked at the target, because certainly a 260 shooting a 142gr needs to have everything accounted for inside 600 yards, shooter, mid range and target. After all a 10MPH wind at 600 with a 142 is in fact a 1 Mil adjustment. And we all use 10. Big difference if you screwed that up, cause if you checked at shooter and it is 3MPH plus mid range and you missed checking the target and it 10MPH, big miss. That is .7 seconds versus what might be .3 seconds at 300 yards, that .3 seconds gives the wind an awesome amount of time to work on the bullet, pushing off. Then again, a 2 MPH (Let's assume a mistake of that magnitude) is .2 mils with that 142gr bullet at 600 yards. I mean the bullet slowed down right.
No, these threads are my favorite to read, all the anecdotal evidence, the 3 hand data, so valuable many suggestions.
Personally I think the barrel warped at the last few inches where it sat in the safe, that, or it was lunar drift as we have had a rather large Moon effecting the Earth's gravity over the past few weeks. Lunar Drift is often overlooked, and combined with Coriolis can easily cause a miss, that is excuse #7 ... I would check Space.com for any asteroid or comet sightings, any reports of Alien UFO activity in the area, they use magnetic propulsion which can move the bullet.
G
Guest
Guest
I was figuring a hard ware issue since it was fine last time I had it out at range last year...
And while. Know all the normal things that would cause this... "Off scope".. The scope was all checked out last summer when I had the 10mil turrets put in...
So I like to read other opionins even if 90% and wrong... There may be 1 thing I over looked....
I would check that the scope is mounted true and level and also that the reticle is level in the scope. Also when shooting that thew rifle is level so you don't have any cant during shooting to induce POI shifts.
Just want in the back and checked with a plumb ... Scope/mount/anti can't.. all level...
So could be a tracking issue...
Will check out that this week and set up my swfa as a backup..
So could be a tracking issue...
Will check out that this week and set up my swfa as a backup..
These threads crack me up, it's like the worst game of "telephone' on the planet.
Spin Drift going the opposite direction, hey don't sweat it I like to use SD as an excuse too... makes you sound, worldly. It's one of my top 14 excuses.
A Foot of deviation from 1 degree of cant, ya that has to be right, he quoted someone smart. Forget the tolerances on scopes are 3 degrees or less when assembling the reticles, if they (manufacturers) can't hold less, I am sure we can, easily. Those 1/2" levels are the cat's ass, the company that makes them said so. I mean they wouldn't sell it if I didn't absolutely need it. Only problem, isn't 1 mil of offset 21.6" at 600 yards... oops, maybe it was that 3 degrees.
Phantom Winds not checked at the target, because certainly a 260 shooting a 142gr needs to have everything accounted for inside 600 yards, shooter, mid range and target. After all a 10MPH wind at 600 with a 142 is in fact a 1 Mil adjustment. And we all use 10. Big difference if you screwed that up, cause if you checked at shooter and it is 3MPH plus mid range and you missed checking the target and it 10MPH, big miss. That is .7 seconds versus what might be .3 seconds at 300 yards, that .3 seconds gives the wind an awesome amount of time to work on the bullet, pushing off. Then again, a 2 MPH (Let's assume a mistake of that magnitude) is .2 mils with that 142gr bullet at 600 yards. I mean the bullet slowed down right.
No, these threads are my favorite to read, all the anecdotal evidence, the 3 hand data, so valuable many suggestions.
Personally I think the barrel warped at the last few inches where it sat in the safe, that, or it was lunar drift as we have had a rather large Moon effecting the Earth's gravity over the past few weeks. Lunar Drift is often overlooked, and combined with Coriolis can easily cause a miss, that is excuse #7 ... I would check Space.com for any asteroid or comet sightings, any reports of Alien UFO activity in the area, they use magnetic propulsion which can move the bullet.
Brutal.
Joe
Taking your word that wind was not a factor. Dropping a plumb bob from the wall and lining your reticle up to it then calling the scope level to the rifle will not ensure that your scope is not canted. The erector assembly is what needs to be leveled, Do a box test.
IF the box test works out then it was phantom 10mph winds, lunar Coriolis spin drift induced 142 funkyness
IF the box test works out then it was phantom 10mph winds, lunar Coriolis spin drift induced 142 funkyness
I guess one thing I'd mention is that if a cant error is introduced, it will result in an impact low and in the direction of the cant. This is for cant only independent of other exterior ballistics. Your post "implies" the rounds impacted on the 3/9 line. If this indeed is the case, you don't have a cant issue.
I welcome any correction if what I say is not correct.
I welcome any correction if what I say is not correct.
Make a large 100yd target and place a dot at the bottom. shoot 100 yard zero and keep adding 100 yards to the zero with the same hold. Bullets should hold a vertical alignment up the page if properly tracking. If they do I would suggest looking at the wind or position harder.
Something like this below. You can see some shots covered in the light colored masking tape that start wandering to the right as the MOA are dialed on. That scope was mounted fast and had cant.
Sooooo...
Mounted the swfa.. Zeroed ... Ran up 6mils dead on for wind..
Remounted the razor... Zero.. Ran up 7mils.. Dead on.. :/
Went back to 425 .. 1st round hit dead on... Want to 665.. .5right.. Partner was the same.. So can figure that was wind ..
So not sure if it was pulling and remounting or something else..
I'll still take the swfa just in case.. Hope not to use it.. I phucking hate the zoom and paralx adjustments... Even worse when its cold...
Mounted the swfa.. Zeroed ... Ran up 6mils dead on for wind..
Remounted the razor... Zero.. Ran up 7mils.. Dead on.. :/
Went back to 425 .. 1st round hit dead on... Want to 665.. .5right.. Partner was the same.. So can figure that was wind ..
So not sure if it was pulling and remounting or something else..
I'll still take the swfa just in case.. Hope not to use it.. I phucking hate the zoom and paralx adjustments... Even worse when its cold...
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