Embarrassing elevation question

[270windude]

I tried out my new Vector scope yesterday and am quite pleased. I’d fire a shot, adjust up and fire, repeated with excellent and consistent results but took forever. Now I’m maxed out and at my 10 yard target I’m still shooting about an inch low. 

Gun in Gamo CFR, scope is 30mm with 50mm objective, and mounts are cheap one piece UTG 30mm from Amazon. 

My gun is taken apart currently for some stock and internal working but hoping to solve the problem before I head out to shoot next. 

 

[JimNM]

You are too close to the target. The barrel is lower than the scope, and the pellet is launched at an upward angle in relation to the line of sight. As the pellet moves down range, it will slowly climb to the point of apex, where the acceleration of gravity will erode the upward vector and the pellet will begin it's unstoppable descent to the ground. Your target is too close, and the scope cannot adjust far enough to accommodate the short distance.

There is good discussion on this thread...

https://www.airgunnation.com/topic/holdover-or-holdunder/

 

[270windude]

I was wondering about that. I left as soon as I got it an inch low at ten yards. Just didn’t know if that was characteristically an issue. I wish I’d have shot another group at 30 which is where I started at but had to move closer to get on paper. I suppose before I play with ChairGun for my guns trajectory I’ll get it shooting at 25 and just hold over or under otherwise. 

 

[Yo]

Buy a cheap $15.97 shipped (Retails over $30) droop compensating mount and be done. Or bend your barrel up.

You MAY have to Dremel it a little if that Vector Scope's belly is too fat. No big deal.

 

[ChrisUSA]

Yes, get it sighted at 25 and while you are at it, put a shim under the scope (between ring and scope) at the rear ring. Maybe plastic bottle or credit cards worth,... .010" approx..

You have to get that elevation back down. Right now, you can not trust that scope to hold adjustment at all. From there, use hold (over) as you said. If you think about it,.. if you were shooting at 3 feet, your scope is higher than your barrel. The pellet will hit low at that same amount. The gun must be (raised) for you to get the pellet to hit at point of aim. That means the center of the cross hairs would be (above) the target,... hold over.

Keep us posted as to how you are getting along.

 

[c_m_shooter]

Buy a cheap $15.97 shipped (Retails over $30) droop compensating mount and be done. Or bend your barrel up.

You MAY have to Dremel it a little if that Vector Scope's belly is too fat. No big deal.

This

 

[bandg]

Yes, get it sighted at 25 and while you are at it, put a shim under the scope (between ring and scope) at the rear ring. Maybe plastic bottle or credit cards worth,... .010" approx..

You have to get that elevation back down. Right now, you can not trust that scope to hold adjustment at all. From there, use hold (over) as you said. If you think about it,.. if you were shooting at 3 feet, your scope is higher than your barrel. The pellet will hit low at that same amount. The gun must be (raised) for you to get the pellet to hit at point of aim. That means the center of the cross hairs would be (above) the target,... hold over.

Keep us posted as to how you are getting along.

Agree with sighting at 25 yards (20 might be enough) but 10 yards is too close. But I couldn't disagree more with the shimming. I don't believe it is good for the scope. I don't do it, many others don't do it, and many believe it is fine.

 

[ChrisUSA]

Yes, get it sighted at 25 and while you are at it, put a shim under the scope (between ring and scope) at the rear ring. Maybe plastic bottle or credit cards worth,... .010" approx..

You have to get that elevation back down. Right now, you can not trust that scope to hold adjustment at all. From there, use hold (over) as you said. If you think about it,.. if you were shooting at 3 feet, your scope is higher than your barrel. The pellet will hit low at that same amount. The gun must be (raised) for you to get the pellet to hit at point of aim. That means the center of the cross hairs would be (above) the target,... hold over.

Keep us posted as to how you are getting along.

Agree with sighting at 25 yards (20 might be enough) but 10 yards is too close. But I couldn't disagree more with the shimming. I don't believe it is good for the scope. I don't do it, many others don't do it, and many believe it is fine.

I do not disagree,.. but I do not compete, I do not optically center, I do not bend barrels. I use tooth paste tube material to shim. Works wonderful. I have done that on a TX200, LGU, M-rod and Maximus. For the Red Wolf, I opted for fully adjustable SportsMatch rings. I shim only to keep the elevation down a bit more. Of course,.... people can get carried away and over shim and bend something. Some finness and common sense are required.

 

[Feinwerk]

You may not have to change anything with your mount. Does your scope reticle have aim points below where the main crosshairs intersect? If so, then it is just a matter of choosing one of the mil dots below the center crosshair intersection, to provide hold over at 10 yards. Then you can return your elevation adjustment closer toward the center of its range and just remember to use the appropriate hold over Mil dot at your 10-yard distance.

Most of my air rifles are sighted in at 30 or sometimes 20 yards. I always have to use hold over at 10 yards and use a different AimPoint from the reticle that is below the center crosshairs.

 

[Yo]

When I buy used scopes I make sure to ask if they have EVER been mounted.

Then on a PCP or Springer. (Not stressed at all or jack hammered)

Then if the scope was ever used for repeated clicking if it's a Chinese scope.

Then what kind of mounts used if they were Burris with the perfect plastic inserts.

 

[bandg]

Yes, get it sighted at 25 and while you are at it, put a shim under the scope (between ring and scope) at the rear ring. Maybe plastic bottle or credit cards worth,... .010" approx..

You have to get that elevation back down. Right now, you can not trust that scope to hold adjustment at all. From there, use hold (over) as you said. If you think about it,.. if you were shooting at 3 feet, your scope is higher than your barrel. The pellet will hit low at that same amount. The gun must be (raised) for you to get the pellet to hit at point of aim. That means the center of the cross hairs would be (above) the target,... hold over.

Keep us posted as to how you are getting along.

Agree with sighting at 25 yards (20 might be enough) but 10 yards is too close. But I couldn't disagree more with the shimming. I don't believe it is good for the scope. I don't do it, many others don't do it, and many believe it is fine.

I do not disagree,.. but I do not compete, I do not optically center, I do not bend barrels. I use tooth paste tube material to shim. Works wonderful. I have done that on a TX200, LGU, M-rod and Maximus. For the Red Wolf, I opted for fully adjustable SportsMatch rings. I shim only to keep the elevation down a bit more. Of course,.... people can get carried away and over shim and bend something. Some finness and common sense are required.

Glad to know it has worked for you. I can certainly understand the concept of some common sense and a bit of finesse being needed, and the degree to which such might damage a scope is not an ascertained fact, if indeed any damage is possible. But it doesn't seem that it can be argued that IF the scope tube is straight, and IF the receiver is level, and IF the mounts are machined accurately (all things that I would expect most consider to be expected), THEN any shimming at one end will result in uneven contact in the ring at the other end (as well as on the cap of the shimmed ring). It is simple geometry. The question seems to be HOW MUCH of this would cause damage on any particular gun/ring/scope combination. You shim and it has worked for you. I don't because I believe it may damage my scope and it isn't worth the risk to me. How much difference in cost are we talking about from a good quality non adjustable set of rings to a Sportsmatch set of fully adjustable rings? Not a lot in terms of gun and scope cost. Worth it to me, not to others. Different strokes.

 

[ctshooter]

I have a thought for you to try before spend more money. It just seems odd that you don't have enough elevation for 10 yards - but I guess some combo of guns and scope heights just work out that way - but it's still an odd situation.

I would turn the scope around in the mount. If it's a nothing special UTG mount maybe it was machined at a slight angle and right now the scope it actually pointing up at a slight angle. IF this is true and you reverse the scope in the mount, it should now be at a downward angle a little bit - which is the same things as mounts which build in 20MOA of elevation.

If that doesn't work - just use holdover.

 

[bandg]

I have a thought for you to try before spend more money. It just seems odd that you don't have enough elevation for 10 yards - but I guess some combo of guns and scope heights just work out that way - but it's still an odd situation.

I would turn the scope around in the mount. If it's a nothing special UTG mount maybe it was machined at a slight angle and right now the scope it actually pointing up at a slight angle. IF this is true and you reverse the scope in the mount, it should now be at a downward angle a little bit - which is the same things as mounts which build in 20MOA of elevation.

If that doesn't work - just use holdover.

I agree with the thought but just had a funny picture pop into my mind of the scope pointing backwards on the rifle. Perhaps saying "reverse the mount on the rifle" would convey the idea without the above image.

 

[ctshooter]

bandg - you know there's a reason for every single little warning on every package we buy. it's hard to believe sometimes, but someone had to have done it or it wouldn't be on the warning label.

 

[bandg]

Certainly true. Every time I mess something up the first thing I do is reach for the instructions and throw them away before I can read what I wasn't smart enough to read first.

 

[Yo]

My guess is that he MUST have a high or maybe even mid magnification scope to bot have enough clicks to zero at 10 yards. If it were only a 2-7x or 3-9x shouldn't max out the clicks. Probably still really cranked up though way way way outa optical centeredness.

 

[ctshooter]

ok - seen it mentioned twice - what the heck is optical center?

 

[bandg]

Seems you have mechanical center where you go end to end in turret adjustment and then put it in the middle. Optical center seems a bit more nebulous to me but I've read about using a mirror to adjust the turrets until you see a single clear image of the retical. Not sure of exactly what is being centered there or if it makes any functional difference but I guess it can't hurt.

 

[JimNM]

Optical center pits the elevation and the windage adjustments on the middle of the range. Different ways to do it.

Simple:. Turn dial to the end, count clicks to reach other end. Back off half the count.

Mirror method:. Not sure, have not used it. Put scope face into a mirror. You can see a ghost of the reticle. Adjust until primary reticle and ghost are lined up.

Advanced:. Roller method. Loosen scope rings. Center view on a dot on the wall. Watch the reticle as you roll the scope in the rings. If the dot on the wall stays on the cross hair, then the scope is centered. IIRC, TominCo did a video on this topic. 

 

[ctshooter]

Thanks - I get what you are saying. The optical center of the scopes lenses and the physical center of the tube may not quite line up 100%. So when you do the mechanical halfway through the click range, you're in the middle of something - but not necessarily the ideal optical center.

I don't see how going through that much work matters when you're gonna move the reticle around anyway for elevation and windage. 

I don't compete so I doubt I would benefit from much of a fine adjustment.