I want to lossen my scope and slide it back an inch. Will this cause it to have to be resighted in again?
Rifle Scopes movingmy scope back
- Thread starter cornhusker
- Start date
guess I should have ask how far off you thinks it might be..it's sighted fer 300 right now
You should not be off a 6" target at 300yds if all your doing is moving it 1" back. I've moved mine more than that an they were less than a 1/2 moa different from the previous zero.
OK, now somebody has to explain how the rail cant and moving the scope either on the rail or just sliding it back in the rings is gonna effect zero in any way. I can see a very slight effect if the scope is not rotated perfectly square either before of after but elevation adjustment should not be effected at all.
You do understand that moving the scope 0.001" in any direction will move the poi right at 1 moa right?
Yes, I do understand that. I'm a mechanical engineer and a millwright. The OP stated he was going to slide the scope in the rings. In other words, he was moving it within a tube, no different than if the scope were a solid shaft. If all is properly machined and aligned, he is only making an axial move to the scope. Forward or back should have no effect on the elevation adjustment as the angle of the scope should not change. The same would be true for a well machined and installed rail. The angle of the scope relative to the bore axis is not changed here, so long as the rings are properly torqued and were properly torqued before he made the move.
I'm not saying he will attain a perfect zero, shit, most folks can't hold a perfect zero anyway. At 300 yards, the movement shouldn't be outside the cone of error for velocity changes of his ammunition.
I'm not saying he will attain a perfect zero, shit, most folks can't hold a perfect zero anyway. At 300 yards, the movement shouldn't be outside the cone of error for velocity changes of his ammunition.
It's a moot point isn't it, or at least an academic one. Who the heck would move a scope and not recheck zero? I mean, we're here because we like to shoot, right?
I guess it takes a while for some of us to figure this crowd out. Set yourself of for a thrashing and sure enough your going to get it. Only if you want it to be accurate. Spoken in true Low Light fashion, direct.
Scope tube outer diameter the same, same ring spacing (side to side clearance the same) an same torque, it should not change at all, in perfect world. However tolerance stacking to 1 thou is very easy to achieve, even when your dealing with the same mfg, let alone 2 or more.
SubOptimal i get what you mean from math "theory," if your erector zero point is off let's say 40MOA from scope dead center, and we assume at 100 yd, bullet trajectory could be assumed as dead flat, then it's like a right trangle, then Sin(0.667)=Opp/Hyp says POI will shift less than 0.02" low. What's the chances the erector zero is dead center of adjustment range?
However, we've seen unmounting rings from a rifle and putting it back in exact rail slot can change POI because its never possible to mount everything exactly how it was before. What if OP cants scope, then overtightens one side barely pulling the scopea different way, removes the rings completely, or there barely a thick coat of uneven paint where the rings are now at? What if the rail is slightly worn on in the spot where the rear ring sits and now introduces a side shift? Etc etc. Those are the X-factors that are impossible to predict.
But... unless OP does or the rifle is built with something inconsistent ... it "could" have no POI shift, but it would likely change but it will also likely change less than 1/2".
However, we've seen unmounting rings from a rifle and putting it back in exact rail slot can change POI because its never possible to mount everything exactly how it was before. What if OP cants scope, then overtightens one side barely pulling the scopea different way, removes the rings completely, or there barely a thick coat of uneven paint where the rings are now at? What if the rail is slightly worn on in the spot where the rear ring sits and now introduces a side shift? Etc etc. Those are the X-factors that are impossible to predict.
But... unless OP does or the rifle is built with something inconsistent ... it "could" have no POI shift, but it would likely change but it will also likely change less than 1/2".
Again, I'm not backing off from my original statement, remember that 300 yard zero. Damn few people are shooting bug holes at 300, in fact, damn few guns can do that. I will say that if it is my gun, I'm going back to the bench to dial it in after a move. I do like hitting what I am aiming at.
Some interesting comments. I have hot had the time to make the move yet due to work and
weather. But I will post what happens ..I do all my load testing between 300 and 500 yards..
I think moving it back is going to make it easier for me to get a faster focus..223 with wylde
chamber and 7 twist..I have a real good load using 85 gr Barns match burners..Finally after
getting a decent OAL...
weather. But I will post what happens ..I do all my load testing between 300 and 500 yards..
I think moving it back is going to make it easier for me to get a faster focus..223 with wylde
chamber and 7 twist..I have a real good load using 85 gr Barns match burners..Finally after
getting a decent OAL...
No one is saying not to recheck zero. To not do that and assume it will be the same is foolish at best.
welli'mhere to tellyou..I was surprised that it was that freaking far off and 300 yards..I had to shoot into the bank to see where it was hitting...Dam,all I did was slide it back one inch,if even that..
Loosen the rings and slide back..So I guess I learned something today..lmao
Loosen the rings and slide back..So I guess I learned something today..lmao
Im surprised there were naysayers to begin with... and educated ones at that.
the number of variables involved are substantial from torque values to whether the torque wrench was accurate this time vs the first time, whether it canted, vertical vs horizontal rings etc etc.
the number of variables involved are substantial from torque values to whether the torque wrench was accurate this time vs the first time, whether it canted, vertical vs horizontal rings etc etc.
You should have shot it at 100. I would never move a scope and go out past 100 to check if it was on paper. I have moved scopes back in the slots and at 100 in that about 1/4" move never been off more than an inch or so.
I've pulled my scopes out of the rings, took the rings off the base, pulled the base off the action, an the action out of the stock, put everything back together and only been off 3/4-1 moa, from zero.
What scope, rings, an rail are you using?
Me too, most I have seen is a few inches switching scopes between rifles and moving rings. Thats at 100 yards tho, not 300.
The amount of cant on the rail has no influence of its zeroed and moved was my point, because the scope and rail still remain parallel.
The cant makes a difference if you reposition the rings on a canted rail. Whenever I have to move a scope forward or back, I move it on the rails, NOT in the rings. The op never made it clear which he was doing. Perhaps he did not have a receiver mounted rail. In either event the zero will change for one reason or another, period. To not check zero after moving a scope, be it in the rings or on the rail, canted or not is simply a poor approach to fundamental accuracy for a rifle. At least if one gives a dam about maintaining optimum accuracy anyway.
I never said he didn't need to check his zero, in fact I said the opposite and it would be off.
You do realize rails are canted to the action? Meaning moving the scope or rings keeps them on the same angle, how would that affect the zero to be off a huge amount?
The only way I see what you are implying happening is if they were called 20moa radius rails.
Tolerance stacking is what will cause the zero to be different after moving.
None of this really matters, because he has already seen the results of moving it at 300 yards.
You do realize rails are canted to the action? Meaning moving the scope or rings keeps them on the same angle, how would that affect the zero to be off a huge amount?
The only way I see what you are implying happening is if they were called 20moa radius rails.
Tolerance stacking is what will cause the zero to be different after moving.
None of this really matters, because he has already seen the results of moving it at 300 yards.
All I did was lossen the rings and slide it back.I marked the rings so that it would not be canted.I am guessing it was off from 300 yard zero
approx.,18 inchs high,which I don't understand being that much....Anyway all's well and ready for 500 yards next weekend..At least the eye relief
is a lot better now..
approx.,18 inchs high,which I don't understand being that much....Anyway all's well and ready for 500 yards next weekend..At least the eye relief
is a lot better now..
This was really interesting to read I'm doing the same thing next trip out. Left scope in rings and moved rings back 2 slots(20MOA rail). Will be interesting to see what my zero change ends up being.....you did have a canted base correct? I've done it on flat bases and it was minimal, but apparently the 20MOA base will have more to say about that.
