Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Long Range Scopes and Other Optics

Long Range Scopes and Other Optics Nightforce Optics


Reply

Leupolds Repeatability

 
LinkBack Thread Tools Display Modes
  #1  
Old 03-03-2005, 06:21 PM
Silver Member
 
Join Date: Apr 2004
Location: Northern California
Posts: 180
Leupolds Repeatability

I have a leupold VX III 6.5-20X40 with target turrets and was shooting the other day and to find out how much elevation and windage I have to work with I ran the ajustments to the top and bottom of their range when I reset the knobs to zero and resumed shooting the scope was no longer zeroed [img]/ubbthreads/images/graemlins/mad.gif[/img]. Is this a malfunction or have other people had the same problem. The change wasn't huge maybe 3/4 in at most but enough to annoy me. And I don't consider this acceptable for hunting purposes. What should be done about this?
__________________
I shoot 1/4 inch groups at a 1000 yards. That is...till my second shot.
Reply With Quote
  #2  
Old 03-03-2005, 08:05 PM
Silver Member
 
Join Date: May 2004
Location: southeast michigan
Posts: 495
Re: Leupolds Repeatability

...you're probably dealing with the "lash" issue associated with Leupold scopes... while they are extraordinary in most ways, I hear it is pretty common to have lash in the adjustments... some recommend setting the zero only after cranking all the way up and then back down to zero; same thing for windage, if that makes sense to you...hope this helps...
Reply With Quote
  #3  
Old 03-03-2005, 08:39 PM
Silver Member
 
Join Date: Apr 2004
Location: Northern California
Posts: 180
Re: Leupolds Repeatability

Thanks I may just have to try that, because other wise the scope is great for me. Although it may prove to be difficult with the windage because of the nessescity to turn the turret both ways due to the direction of the wind.
__________________
I shoot 1/4 inch groups at a 1000 yards. That is...till my second shot.
Reply With Quote
  #4  
Old 03-03-2005, 09:16 PM
Silver Member
 
Join Date: May 2004
Location: southeast michigan
Posts: 495
Re: Leupolds Repeatability

...I may have been thinking about the lash in the side focus parallax adjustment, and not the tracking issue you referred to...there is a good article on Leupold "tracking & side focus lash" on www.6mmbr.com/optics.html they also have a comparison article there between the Leupold & Nightforce; Leupold seemed to have better color rendition, but the Nightforce had no lash or tracking problems (much more money, of course)... personally, I like them both and would buy either one at the right price, for the right application...hope this helps...
Reply With Quote
  #5  
Old 03-04-2005, 09:17 AM
Platinum Member
 
Join Date: Jun 2007
Location: Fredericksburg VA
Posts: 4,058
Re: Leupolds Repeatability

there is a fix for that problem with Leupolds. commonaly called the Tucker conversion.

Cecil Tucker (432) 530-2919 or bpdms@aol.com is a gunsmith in Tx that is the premier scope guy for the BR communitiy in this area.

For $175 he puts a zero stop like the NF that takes up all the slack in the Leupolds and makes them 100 % certain and accurate on the click movements. He also does paralax work on them.

BH
Reply With Quote
  #6  
Old 03-04-2005, 12:12 PM
Platinum Member
 
Join Date: Jun 2001
Location: Palmer, Alaska
Posts: 2,539
Re: Leupolds Repeatability

BH,

Is it the zero stop thing that Cecil puts on that removes the slack? If so, it must be a different concept than that of Nightforces in order to accomplish it, because I don't see how it comes into play until the turret is dialed all the way in to the stop? Backlash is a result of a loose thread fit and unless he replaces them in some way, I don't see how it could be corrected.



When you unscrew either turret, it relies on a spring to push the erector tube tightly against the turret as it's backed away from this inner tube. If these leaf springs are weak, (and most say Leupold uses somewhat lighter springs) and drag even a little and stick, the tube may not be moved the calibrated amount at some point upon turret rotation, then all of a sudden it may free up and move a couple or more clicks at once... possibly after recoil from firing the rifle.

The solution most folks make habbit in order to avoid this problem if it exists or not is to unscrew the turret 1 MOA or so past where you intend to set it, then screw it back in the 1 MOA "toward" the spring to preload it... windage or elevation. Lefty loosy, righty tighty... think of the turret as pushing the bullet the direction you want it to go and you never have to look at a turret to know which way to dial. In a in a 9 O'clock wind, you need to push the bullet back left, so the turret gets screwed in to push it back left. In this case, you've already preloaded the spring so dialing 1 MOA past, then back 1 MOA is not necessary. If wind was at 3 O'clock and you unscrew the turret to let the spring push the bullet back right, the spring is unloading and should then be preloaded again, same as dialing out to a farther range unloads the elevation spring.

The best thing to have is stronger springs and ultra precision fit turret threads, which is why Nightforce is known for its tracking and repeatability.

Lock your rifle down in a rest so it does not move when you make turret adjustments and with a grid target, make a thurough check its tracking and repeatability throughout its full range, both turrets. This is the only way you too can truely calculate what your turrets are specifically calibrated at per click, and if that remains consistant throughout the whole range.

Other things to consider, as you were already preloading the spring when you returned to your 100 yard zero, are things like; was the barrel fouled and settled in when you zeroed it, or did it shift slightly as it fouled in while you fired more further out, was your rifle recoiling consistantly, as in same type rest and grip on rifle etc, had your barrel temp become drastically different as you switched ranges, etc...

Definitely will require some time and careful study to be sure of the cause.
__________________
Brent Moffitt
Reply With Quote
  #7  
Old 03-05-2005, 09:27 AM
Platinum Member
 
Join Date: Jun 2007
Location: Fredericksburg VA
Posts: 4,058
Re: Leupolds Repeatability

Brent

Cannot explain it technically. But several people I know have had it done, and it corrects that problem. YOu might want to email or call him for the technical aspects, but it is THE measure to clean up Leupolds by all accounts.

I am going to send a 6-20 bumped to 14-35 to him for the fix at the end of the month.

BH
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Leupolds Repeatability
Thread Thread Starter Forum Replies Last Post
scope repeatability oprod Long Range Scopes and Other Optics 2 09-07-2010 11:37 PM
Nikon Buckmaster Repeatability bookworm Long Range Scopes and Other Optics 4 12-22-2008 09:52 PM
Scope Come ups and REPEATABILITY HeskethPritchard Long Range Scopes and Other Optics 11 09-02-2007 12:07 PM
repeatability on rcbs micro pro electronic scales? 30-06 boy Reloading 1 03-17-2006 07:38 PM
Badger Repeatability Ian M Equipment Discussions 9 07-17-2002 03:21 AM

Current Poll
Do You Shoot Rifle Competition?
YES - 34.11%
732 Votes
NO - 65.89%
1,414 Vote
Total Votes: 2,146
You may not vote on this poll.

All times are GMT -5. The time now is 01:44 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC