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Old 08-06-2018, 11:58 AM
chicks2111

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Long range torque drift??



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I am wondering if I have discovered something or just a victim of the wind spirits...Every time I go to the range to get ready for the fall muzzleloading season I go through the same frustrating drill.
I am shooting a stainless CVA Accura .50 with a 209 Mag primer, 3 50 grain 777 pellets and Barnes TEZ 250's. The rifle is topped with a Nikon 3-9 with a BDC reticle.
I get the point of impact dead on using the crosshair at 100 yards, then shoot 200 and 300, using those reticle circles.
Inevitably, the 200 yard shot will hit maybe 1" to the right, and the 300 yard shot will land as much as 5 inches to the right.
Seeing this, I put in a sight correction of maybe 3 clicks left. Guess what...next time I shoot at 100, the impact will be 3 clicks to the left of center.
Could there be a rotational drift at the longer ranges or just an unnoticed wind spook? Maybe I'm the only one who doesn't know the answer to this????
Scope not mounted perfectly plumb?
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  #2  
Old 08-07-2018, 12:32 PM
farm boy
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Try doing the "box" test with your scope to see if it is tracking properly.
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Old 08-07-2018, 01:02 PM
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Verticle tracking test. Guessing it's not true.

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  #4  
Old 08-08-2018, 11:46 AM
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Originally Posted by Topstrap44 View Post
Verticle tracking test. Guessing it's not true.

Topstrap
My guess is the scope crosshairs are not lined vertically with the bore. This would mean you will be accurate at the distance sited in only. This means as the distance changes the bullet impact will shift sideways.
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  #5  
Old 08-09-2018, 10:43 AM
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Try some different slugs?
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Old 08-09-2018, 12:13 PM
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I shoot long range silhouette with .22, and by the time we're shooting the 200 meter target I've dialed in 4 to 5 clicks left to compensate for rotational drift (or what ever it's called) of the bullets right hand spin.
I've needed to do this with all three rifles I've used, as do all of my fellow other shooters. Your drift will be a bit less because of the lower veloctiy of the .22.

Now you could have scope issues, but I don't as far as being level and aligned with the bore.
I use an EXD Engineering Scope device that will instantly show if my scope is out of line with the bore. It also of course insures that the scope is perfectly level.

#1:
So it may just be the rotational thing.
#2:
If you scope is canted even a little bit, that would account for your problem.

#1 or #2, or combination of the two are probably responsible for your issue.

#3:
It may be your scope is misaligned with the bore. If you scope is off by 1, that will be 180 inches at 300 yds, and yes you read that right. Now that means it only has to be 3 one hundredths of a degree off to miss left/right by 5 inches.
It's the least likely reason, and takes the EXD tool to show that small of an misalignment.

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Last edited by Smoothtrigger; 09-10-2018 at 10:02 PM.
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Old 08-09-2018, 01:35 PM
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[QUOTE=Topstrap44;11120907]Verticle tracking test. Guessing it's not true.

I agree, Chances are the reticle may not be perpendicular and that is the reason for your impacts being off. I have seen this before and using a plumb bob to set the verticle of your scope along with using levels to make sure the scope isn't canted when shooting can be helpful.
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Old 09-10-2018, 07:34 PM
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I shoot a .600 Snider almost daily, it's affected by the wind like nothing else I have ever owned. It taught me how to read the wind and how much to adjust for windage, I'm getting quite good at it now.


Last edited by Explosive; 09-10-2018 at 07:37 PM.
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Old 09-10-2018, 07:56 PM
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Quote:
Originally Posted by farm boy View Post
My guess is the scope crosshairs are not lined vertically with the bore. This would mean you will be accurate at the distance sited in only. This means as the distance changes the bullet impact will shift sideways.
Correct. farmboy is the winner. This is a common problem.
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Old 09-10-2018, 09:16 PM
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If you are consistently only one inch out at 200 yards with a bleedin muzzle loader, you must be the best shot in the world.
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Old 09-12-2018, 11:40 PM
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Cool rifle!

Quote:
Originally Posted by Explosive View Post
I shoot a .600 Snider almost daily, it's affected by the wind like nothing else I have ever owned. It taught me how to read the wind and how much to adjust for windage, I'm getting quite good at it now.

Wow, a .600! That sounds like a lot of fun. Love to see some more photo's of your rifle if your up for posting them. Thanks in advance! Joe
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Old 09-13-2018, 12:05 AM
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Quote:
Originally Posted by gunsmither View Post
Wow, a .600! That sounds like a lot of fun. Love to see some more photo's of your rifle if your up for posting them. Thanks in advance! Joe
I have two, a MkIII short rifle built as a breech loader shown in the pic above and a MkII** converted from a muzzle loader. I just got the sights sorted on the MkII** so will be shooting that one too now.



https://www.youtube.com/watch?v=c8brRmde0o0

Last edited by Explosive; 09-13-2018 at 12:24 AM.
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Old 09-13-2018, 01:06 AM
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I have 3 Sniders and 2 Enfield muzzle loaders. They are all 577s. I hadn't heard of a 600 Snider before.

Two Sniders are carbines and one a full rifle. I have fired the two carbines quite a few times in BP competitions. The rifle is devoid of any markings and most likely a Kyber Pass rifle. I will never fire it.

One carbine is a cavalry model with saddle ring the other is an Enfield muzzle loader conversion with the old "suicide" action - no lock latch.

You are right about the wind but the other issue of course is the rainbow trajectory. My Cavarly carbine is surprisingly accurate although my aged eyes now have issues with the closely placed rear sight.
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  #14  
Old 09-13-2018, 08:04 AM
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The .577 bullet is too small to fit the rifling properly, use bullets sized to .600 and seated to touch the rifling for good performance.

PS, You will need to make a custom bullet sizer and case neck sizing dies to be able to do that, but it's worth the trouble. I use 16.6 grains of Unique.

Last edited by Explosive; 09-13-2018 at 08:35 AM.
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  #15  
Old 09-23-2018, 08:26 AM
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Quote:
Originally Posted by chicks2111 View Post
I am wondering if I have discovered something or just a victim of the wind spirits...Every time I go to the range to get ready for the fall muzzleloading season I go through the same frustrating drill.
I am shooting a stainless CVA Accura .50 with a 209 Mag primer, 3 50 grain 777 pellets and Barnes TEZ 250's. The rifle is topped with a Nikon 3-9 with a BDC reticle.
I get the point of impact dead on using the crosshair at 100 yards, then shoot 200 and 300, using those reticle circles.
Inevitably, the 200 yard shot will hit maybe 1" to the right, and the 300 yard shot will land as much as 5 inches to the right.
Seeing this, I put in a sight correction of maybe 3 clicks left. Guess what...next time I shoot at 100, the impact will be 3 clicks to the left of center.
Could there be a rotational drift at the longer ranges or just an unnoticed wind spook? Maybe I'm the only one who doesn't know the answer to this????
Scope not mounted perfectly plumb?
While other posters are correct in that it is probably a scope level issue there is a real problem with bullet drift at long ranges, though it won't show up at relatively short ranges of 300 yards. The Buffington sights on Trapdoor Springfields and Springfield 1903s correct for precession, the drift imparted by the spinning bullet as it descends onto the target from it's high arc at very long distances. You will note that the ladder does not climb vertically but leans to the side to compensate for precession. Those were marksmen's sights, good in competitions but too complicated for the battlefield.
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