Custom rings? Just loosen the screws on any rings and rotate. Am I missing something here?
Yes!! start reading from the top down!!!
Custom rings? Just loosen the screws on any rings and rotate. Am I missing something here?
This is my fav pic of bubble levels. And the reason why you should only adjust your scope bubble to 'zero' when vertical stadia are lined up on a plumb bob!Recommend a level bubble
What’s a decent level to put on a pic rail or scope tube. Thanks!forum.accurateshooter.com
The scope only knows the scope and gravity (and a few other effects). The location of the barrel means nothing (relatively speaking). It's a tube that launches the bullet.
It would only matter if the sights were attached to the receiver and functioned relative to the receiver.
Bullets drop relative to a plum line parallel to gravity.
As to whether the bullet knows it was offset from the bore half an inch... after several yards I dare say it's forgot.
Are you saying that if u had had a zero moa rail you could have avoided rotating the rail? From discussion in this thread the cant to the rail is immaterial, but obviously a 20 moa rail would exaggerate the offset effect even more. (?)As long as your scope height (from centerline of bore) is entered correctly in software, the vertical will be fine with scope offset and the POA set plumb through elevation adjustments.
Horizontal offset presents an angular error on that plane. You'll see that at distances different from your zero.
There is no software that can compensate for that.
I ran with a Tubb 2000 at 7deg cant and loved it.
The difference there and with your setup is that the scope rail adjusted separately to counter that 7degs.
It had to, as it was a 20moa rail.
With that rail counter, the scope was was plumb above center of bore even while the action was turned.
Works fine for you because you zero to and shoot at the x at a fixed distance with a cant and then forget about it! But the physics says if you were then to only adjust for windage then it will also affect your vertical hit by a bit. This wont happen when your scope is on top and the vertical stadia are inline with the arc of the bullet drop. ( as I have recently learned!)
I am late to the discussion, but I’ve been competing at long distances out to 1K for a very long time and I haven’t seen any comment emphasizing the fact that the stated intention is to cant the rifle and then, by adjusting the scope to ensure that the vertical cross hair is plumb, expect the rifle to be accurate at distance. If you remove the scope entirely and rely on fixed sights, canting the rifle will move the point of impact in the direction of the cant. Cant right, point of impact moves right; cant left, point of impact moves left. Using the scope cross hairs to overcome that won’t move the point of impact. Your fired round doesn’t know what’s in the scope image, it only knows that when the rifle fires and the laws of physics takes command, the bullet follows those rules.I just re-stocked my 6br with a MDT chassis and magul prs lite ar15 style butt stock. This ar15 type setup feels so much better when I shoot it canted inwards about 10-15deg. I have straight rings - zero moa. I dont shoot prone.
I re-levelled the scope off a tilting bipod using a plumb line out 30 yds with the cant hold that felt comfortable. And then I adjusted my scope mounted level to the same plumb line. Therefore the scope vertical stadia are in synch with the level.
I know there have been debates over this setup before but the confusion originates on whether or not a +moa rail was being used, which will throw off windage calcs, other than at the zero distance.
In my case the scope is perfectly aligned with the bore and aligned to gravity when at the cant angle. I would like to be able try out this configuration for ranging and dialing at varied distances out to 1000 using my conventional dope.
Anyone see any reasons why my configuration wont work identically to a 'straight up on top' conventional scope setup?
You might hear the sniper say it if he tried shooting offhand, or off the hood of a humbee, using a rifle with an ar15 style stock!I am late to the discussion, but I’ve been competing at long distances out to 1K for a very long time and I haven’t seen any comment emphasizing the fact that the stated intention is to cant the rifle and then, by adjusting the scope to ensure that the vertical cross hair is plumb, expect the rifle to be accurate at distance. If you remove the scope entirely and rely on fixed sights, canting the rifle will move the point of impact in the direction of the cant. Cant right, point of impact moves right; cant left, point of impact moves left. Using the scope cross hairs to overcome that won’t move the point of impact. Your fired round doesn’t know what’s in the scope image, it only knows that when the rifle fires and the laws of physics takes command, the bullet follows those rules.
That said, if a shooter chooses to shoot with the rifle canted to one side or the other, so be it. But it would be absurd to expect consistent accuracy using that method. You will never find a successful sniper saying “I like to cant my rifle because it feels better.”
No, if the scope is offset horizontally from local bore centerline, you have a horizontal error.Are you saying that if u had had a zero moa rail you could have avoided rotating the rail?
I now totally visualize all of this. I think the wiser move is to re-set up square and shoot LR off bench that way. If i am shooting it offhand or with field aids at steel and cant then just hold off accordingly, if even necessary. For that kind of shooting pinpoint precision is not on top of list. The rifle in discussion is all around not just one purpose.No, if the scope is offset horizontally from local bore centerline, you have a horizontal error.
This, even while you've overcome elevation error.
If for example the scope is offset 1/4" with your cant, that 1/4" of horizontal error would be adjusted out with your zero, but the angular path remains beyond your zero. Further out you'd be around 1/4" off on the other side, and growing with distance.
If you use what I call a click-card in the field, you might pre-calculate or test for the horizontal offset error per range. Then compensate. And where you're more comfortable with a canted gun, shooting it better, I see no harm in going with it. Just be sure to test your capabilities -so that you know them, and stay within them.
Hear Hear! esp the last paragraph.My understanding is this...
A level scope is crucial. If you cant the scope when shooting at distance you are rotating two points within the scope, the original 100 yard zero and the dialed (up) distance. Shooting while canted can produce significant left/right error because you're now holding your point of aim far above and to the left/right of the actual 100 yard zero and gravity will cause the bullet to fall straight down. A quick illustration you can do at the bench, tilt your rifle and dial in elevation and watch where the crosshairs go.
Having the rifle stock level and barrel exactly centered under the scope is not crucial, assuming you keep the scope level. If you choose to run a canted stock, once you zero your rifle at 100 yards you are just left with a slight horizontal offset of scope over bore (scopes and barrels are just tubes, they don't know if a rifle stock is level or not). The difference here is that this is a linear error compared to the nonlinear error of canting your scope. If your scope is 1/4" offset to the side of the barrel and zeroed at 100 yards you will be perfect at 100, 1/4" offset at 200, 1/2" offset at 300, 1" offset at 500 yards, 2 1/4" off at 1000 yards and so on in a linear fashion. This is a MUCH smaller issue than tilting scope off level when shooting.
Many people choose to run a canted rifle under a level scope and that's a reasonable choice. The benefits of the gun fitting your body and helping you naturally keep the scope level (and also possibly help manage recoil better) could possibly outweigh the slight offset error.
And finally...why not just zero at 1000 and then dial down for lesser distances? This way the horizontal linear error would never be more than the offset distance??