Extreme Turret Adjustment?

[Bo3b]

Out-of-box new scope is about 2.50" POI inches low at 10 yards for goal of 40 yard zero. And 0.1 MIL/click reticle would require about 60 clicks to correct, near limit of scope specs 15 MIL (75 clicks any direction from center) max Elevation and Windage.

Question is - Adverse affects, mechanically or optically, to scope when zeroed at extremes of adjustment?

Thanks,
Bo3b

 

[c_m_shooter]

This is why they make mounts with droop correction built in. You haven't mention what rifle you have it on. You can shim the rear ring with tin can scraps if you are shooting a PCP. A set of adjustable rings or an angled mount would be the ideal solution. If you have a break barrel springer, you can just bend the barrel up.



15 clicks from topped out would not work for me because I shoot field target and click for each target. I need 7 moa of upward adjustment from zero. I prefer it to be within about a turn of center when zeroed. Some others are more particular.

 

[ChrisUSA]

Don't do it! Zero out at 25 yards or so. Shim the scope at the rear ring where the scope meets the bottom half of the rear ring while you are at it. Maybe .010" or so. This will further help to keep elevation down.

 

[likkitysplyt]

Most people generally like to keep their scopes as close to optical zero as possible. Adjusting the scope to the extreme limits of elevation or windage is not good for any scope. Scopes have springs inside and the springs can lose their ability to make adjustments when one side is crushed and the other has little or no pressure on it. If it is just your elevation that you are concerned with ... you can get a set of FX No Limit mounts for whatever size tube your scope has. There are other mounts available that will give you some adjustments for windage.

Shalom

John

 

[dc8cappie]

I’m zeroed at 50 yds, 40 is -3 clicks mil scope and 10 yds is the same as 110 yds -2 clicks. Scope fully one way less 1/4 turn with FX unlimited scope rings and still clean image.

 

[GLPalinkas]

Like others stated, best to buy a set of adjustable rings. However, they are expensive. Another solution mentioned but not detailed is cutting strips from an aluminum soda can and using one or two at the most under the scope at the rear mount. That raises the point of impact considerably. I usually use this method on less expensive scopes. I also smooth the edges with some fine sandpaper do as not to mar the scope tube. 
Hope this helps. 

Gary

Venice Fl

 

[lenweber2]

Barrel droop is quite common on air guns, even expencive ones. Some manufacturers are doing 20 MOA in their mounts on the gun itself both for long range and droop.I just don't like shimming. By doing so too much one can bend or mark the scope tube. I think it's Burris that make a ring set with inserts. Or a set of rings that are adjustable. I sight at 30 yards scope opticly centered, fire a round, then with gun held at the fired round position move the cross hairs with the adjustable mounts to the shot or maybe a bit below if yiu will be shooting extreme range. The scope tube is in alignment to the rings so no scope damage.

 

[JamesD.]

I've used scissors and sandpaper for aluminum can shims. I've used window blinds.

I finally learned to use feeler gauges as any thickness you need is available and I get entire sets cheap at flea market. Not only shimming but mounting flat bottom scopes to top of action gives me exact height when you add the stack and exactly 1/2 of the Objective bell in mm's. Perfect exact mounting height for Strelok Pro or any other. I'm extremely particular about center of bore. 
I've been running my SWFA bottomed out with FX No limit Rings getting a zero of up to 97 yards. That's 10 mils holdover & 27 from turret. 37 mils total and sending 28-32 grain RBT slugs at 1070-1040 as set, I can use all of that elevation. Since it's only targets and learning I have pushed it to 450.

I'm gonna take John's advice and loose some mills. Optically center that scope & not max rings out either. I'm gonna stick to 300 with the .22 & leave the long distance to the .257 Scandalous that's coming. 
Since I prefer low magnification 2ndFP scopes, airgun artillery isn't a problem. In fact it's fun when you have a safe backstop that provides a visual splash and dust shows wind speed at POI. 


If you need a set of feeler gauges just pay shipping. If you are having these issues with a springer, get the droop compensated mount and vibra tight or red Locktite. Degrease all screws & shake Loctite well. Let dry 24 hours before shooting if a springer. Then start trying to find your zero. 
If not you'll go crrrazzy, like I did. Good luck

 

[bandg]

Barrel droop is quite common on air guns, even expencive ones. Some manufacturers are doing 20 MOA in their mounts on the gun itself both for long range and droop.I just don't like shimming. By doing so too much one can bend or mark the scope tube. I think it's Burris that make a ring set with inserts. Or a set of rings that are adjustable. I sight at 30 yards scope opticly centered, fire a round, then with gun held at the fired round position move the cross hairs with the adjustable mounts to the shot or maybe a bit below if yiu will be shooting extreme range. The scope tube is in alignment to the rings so no scope damage.

Agree with this totally. I personally look at it this way-if one had rings that were manufactured level (as they should be) and then puts shims under the scope at the rear ring and the shims are flat and at all level then the scope would "float" above the front ring by an amount equal to the thickness of the shim. Tightening the front cap down would then at best apply a bending force to the scope and at worst would have contact on the edges (top rear and bottom front) of the front ring possibly damaging the scope. This is how I view scope shimming. Is it going to damage your scope? I can't say for certain because I don't do it. Maybe it wouldn't. Many claim it doesn't, and many claim it might. And many used scopes are for sale. Are they no longer needed or possibly damaged? Who knows. But it seems the geometry is pretty simple even though the amount of space involved is small-you cannot raise the rear of a straight body scope tube and then have it pass flat through the front ring UNLESS the rings are adjustable. One person's opinion.

 

[JamesD.]

Barrel droop is quite common on air guns, even expencive ones. Some manufacturers are doing 20 MOA in their mounts on the gun itself both for long range and droop.I just don't like shimming. By doing so too much one can bend or mark the scope tube. I think it's Burris that make a ring set with inserts. Or a set of rings that are adjustable. I sight at 30 yards scope opticly centered, fire a round, then with gun held at the fired round position move the cross hairs with the adjustable mounts to the shot or maybe a bit below if yiu will be shooting extreme range. The scope tube is in alignment to the rings so no scope damage.

Agree with this totally. I personally look at it this way-if one had rings that were manufactured level (as they should be) and then puts shims under the scope at the rear ring and the shims are flat and at all level then the scope would "float" above the front ring by an amount equal to the thickness of the shim. Tightening the front cap down would then at best apply a bending force to the scope and at worst would have contact on the edges (top rear and bottom front) of the front ring possibly damaging the scope. This is how I view scope shimming. Is it going to damage your scope? I can't say for certain because I don't do it. Maybe it wouldn't. Many claim it doesn't, and many claim it might. And many used scopes are for sale. Are they no longer needed or possibly damaged? Who knows. But it seems the geometry is pretty simple even though the amount of space involved is small-you cannot raise the rear of a straight body scope tube and then have it pass flat through the front ring UNLESS the rings are adjustable. One person's opinion.

Oh if somebody torques the heck out of what should be 15 ft/inches w/ Locktite, yup, gonna bend some tubes.

A mirror will reveal if the used scope is bent. I went over that in detail and it's in my accuracy relation green balls. 


A PCP doesn't need much torque on rings at all. A springer on the other hand, don't shim. Buy the correct mount or have someone that knows what they're doing align your barrel by bending. 
Bending means very slightly. Instrumentation is used. Not clamp and bend.

 

[ChrisUSA]

My favorite shim material is the flexible, plastic, aluminized?, tooth paste tube. They are pliable, have some grip and sure,.. a wee bit of "squish". A medicine ointment tube would be similar. I do not shim for shimming to a fixed amount,... I just shim to keep the elevation down some more. I will use the bottom (center) 90-100 degrees of the available 180 degrees in the bottom of the rear ring. For the Red Wolf,... I did splurge for a set of fully adjustable SportsMatch rings.

 

[steve123]

Too far on either end of the adjustment ranges can cause two more problems. #1 the image quality is often compromised and it appears somewhat blurry. #2 if the erector is hitting the inside of the tube you can have POI shifts.

I experienced #1 because the rifle I had it on had a 50 moa base on it and the scope only a had a few mils of down elevation left. I thought that there was something wrong with the optical quality of my new scope, then it occured to me what was happening, so I dialed up 10 mils and there was the nice image quality I expected! I put adjustable rings on which solved the problem.

 

[biohazardman]

The UTG 20 MOA riser is an inexpensive way to overcome barrel droop and get back to near optical center on you scope. I used one on my impact until I broke down and bought the FX No Limit rings.

https://www.amazon.com/UTG-Leapers-MT-RSX20MOA-Elevated-Picatinny/dp/B01M1KP7PD

Or if you have a break barrel gun Yo has a good suggestion they have a 1" also.

https://www.walmart.com/ip/RWS-2300597-Lock-Down-Scope-Mount-30mm/23468044

 

[Yo]

JAPAN AND EUROPEAN SCOPES ONLY!

Their turrets are built to handle the extremes in bottoming out. Don't do it if it's Chinese. That's why I no longer click dial of death with any Chinese scopes and just optically center and hold over and save all the clicking with Japan and European scopes.

I shim if the scope is a cheap POS and not mine nor my gun and if a BUDS too cheap to properly buy adjustable mounts and or MOA base and refuse to have me bend his barrel for him. Shoulda seen a Tech force underlever he insisted swimming got over 1/8" worth of coke cans wrapped with electrical tape jacking the rear up. Crappy $100 scope too anyway. Told him the tubes likely to dent he didn't care as long as it shot on target. Was a Springer so for sure it had to have dented the tube to keep it from creeping.

Bending the barrel works too. Best airgun tuner in the world does it and recommends it too.

I personally only use adjustable mounts even for cheap scopes. Noticed sgimming no matter how careful may negatively affect normal scope operations not including possible scope tube stress and damage.

Here's a cheap Chinese made one licenced by a German one. Just Dremel it if the scope doesn't fit perfect. Regularly $30.00 or pay $60-$180 for UK brands.

 

[steve123]

Yo stated - """JAPAN AND EUROPEAN SCOPES ONLY!

Their turrets are built to handle the extremes in bottoming out. """"(Don't do it if it's Chinese)"""". That's why I no longer click dial of death with """(any)""" Chinese scopes and just optically center and hold over and save all the clicking with Japan and European scopes."""

YO you really need to stop making 'blanket statements' like this because it is not the TRUTH. Yes there are plenty of crappy chinese riflescopes but there are some really nice ones that track well.

I've made 1st round hits, or 2nd round hits on steel because I didn't get the wind right on the first shot, with my AR in 6mmFatRat, from 300Y all the way out to 1122Y with a Athlon Talos BTR 4-14x44. That's a $300 chinese scope. I was dialing to see if it tracked and I was using the dope I used with my SWFA 3-15.

But I've tried a bunch of Athlon chinese made riflescopes that seemed to track fine when I dialed, when I say seemed, that means I couldn't tell any difference between them and my expensive Euro scopes. The Athlon Cronus is made Japan and it's a nice scope but the Chinese made ETR has better turrets and tracks just as well.

Last year I won Freestyle division for 4th year in a row in our AZ state FT match with a Athlon Argos BTR 6-24x50 - DIALING the whole time.

Furthermore, I had to send my S&B back twice because the elevation turret failed. The first time because the clicks couldn't be felt anymore, and the 2nd time because they locked up. 

If you frequent optics forums like I do then it becomes pretty obvious that there are plenty of Euro, Filipino, and Jap scopes that have had problems from time to time. In fact the scope with the most problems I've ever read about was the Steiner MX5i upon it's initial release, I think it was $1500 or so. Name a problem and this scope had it. Some scopes were never fixed to the customers satisfaction after being sent back 4 times.

 

[esaz-41]

Recently I bought a Barska 6-24 scope (yea I know) for a PCP. My usual practice is to zero at my ten yard range. On this particular rifle I had first mounted an old Winchester 4X32. I always center the reticle and the Winchester scope zeroed with a few clicks.

I mounted the Barska scope and at ten yards the poi was four inches low with the elevation maxxed. Not a barrel droop issue.

I returned the scope to Barska and they think it's to spec.

I solved the problem by using droop a compensating mount.

To my way of thinking this scope is defective. Am I the only one that has ever experienced this?

 

[esaz-41]

Out-of-box new scope is about 2.50" POI inches low at 10 yards for goal of 40 yard zero. And 0.1 MIL/click reticle would require about 60 clicks to correct, near limit of scope specs 15 MIL (75 clicks any direction from center) max Elevation and Windage.

Question is - Adverse affects, mechanically or optically, to scope when zeroed at extremes of adjustment?

Thanks,
Bo3b

To my way of thinking a new scope with a POI low at ten yards is defective. I t can be used with a compensation mount but that is not the way it should be. In have a Barska 6-24 that is 6 inches low at ten yards, Barska says it is to spec -- it may be but I still think it is defective. BTW in my case the rifle was a PCP -- NO BARREL DROOP!!

Maxxing adjustments in a scope to zero is a bad thing.