New Posts New Posts RSS Feed - Bushnell 8-32x40 scope problem
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Check GunBroker.com for SWFA's No Reserve and No Minimum bid firearm auctions.

Bushnell 8-32x40 scope problem

 Post Reply Post Reply   Topic Search Topic Search  Topic Options Topic Options
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/08/2006 at 05:56
JaJoa View Drop Down
Optics GrassHopper
Optics GrassHopper


Joined: April/19/2006
Location: Canada
Status: Offline
Points: 14

Hi All,

Evidently on May 6,I posted a follow up to my previous inquiries about this

scope in the wrong place! Since I did'nt get the usual quick response to my

post, I hope I'm doing the right thing in reposting my inquiry as a new post!

Here goes:

 

''Hi all,I'm back,

I finally bought the Bushnell Elite 4200,8-32x40 scope,and so far I'm impressed.

As it turned out the base and rings of my present scope (Balvar 8, 2.5x8x) could

not accomodate the new scope.I bought and installed Leupold standard 2 part

base and standard medium (.770) rings.I managed to center my shots on

target at 100 yards after adjusting the large screws on the rear base.At this

distance I was 9'' low.As an example,my question is this: .25'' MOA

corresonds to .25'' (UP) at 100 yards, I gather I would need to move the

elevation dial 36 clicks to attain dead center! then at 200 yards raise it by,

say 3 inches (another 12 clicks)? Does this scope have enough clicks to

this?Now the dealer confirms, that this scope has a one eights MOA,

(sorry I don't know how to write this in fractions with my present keyboard)!

Now I'm really confused.The gradation little lines on the elevation knob are

one sixteenth of an inch, and about seven eights of an inch between the longer

vertical lines.Where do we get one eights of an inch MOA out of this?

I would greatly appreciate some expert advice on this.Thanks''

JJ

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/09/2006 at 06:01
fourinone View Drop Down
Optics Apprentice
Optics Apprentice
Avatar

Joined: January/14/2006
Location: United States
Status: Offline
Points: 169

Hi; assuming you are correct for your gun at 200 yards....on a regular 1/4 MOA click value scope you would have to turn aprox. 48 clicks. On an 1/8 MOA click value scope you would have to turn aprox. 96 clicks.

I did cringe when I read how you mounted and adjusted your rear screws to sight in your gun. You should never try to adjust your point of impact by turning those rear screws!!

I'd would use Burris Signature rings and use the off-set inserts to get as close to zero as possible.

I will not pay extra for the scope on a gun I'm buying used if it is mounted in that type of scope mount.

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/09/2006 at 06:59
JaJoa View Drop Down
Optics GrassHopper
Optics GrassHopper


Joined: April/19/2006
Location: Canada
Status: Offline
Points: 14

Forinone,

Thanks for the quick response.I guess your confirming what I thought,that is

with one eights MOA, and at 100 yards, where I'm 9 inches low, I'll need to

click up 72 times! My question was (and is) will this scope have enough clicks

to do this? You crinched at the way I adjusted the scope from left to right by

adjusting the large screws on the rear base! It seemed I had no choice, since

I clicked right 40 times and I did'nt seem to see any movement.I guess you

mean this action could have affected the front rings or something! The store

presented me with a choice of either Burris or Leupold standard base and

rings.If I need to click, to attain zero, dozens of times on the scope, I don't

mind doing this, as long as it can be done.Thanks for your help.

 

JJ

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/10/2006 at 04:38
fourinone View Drop Down
Optics Apprentice
Optics Apprentice
Avatar

Joined: January/14/2006
Location: United States
Status: Offline
Points: 169

Hi; you may want to take a hard look at the Burris Signature Rings in a dual dovetail set-up and use the off-set inserts to get you on zero while the turrets are back to the factory or optical center.

 

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/11/2006 at 11:46
koshkin View Drop Down
MODERATOR
MODERATOR
Avatar
Dark Lord of Optics

Joined: June/15/2004
Location: United States
Status: Offline
Points: 10963

Total adjustment range for this scope is 20" at 100 yards (this information is also contained in the documentation that came with the scope).  That means you have 10" of UP adjustment at 100 yards.  If your scope is centered mechanically and is 9" low at 100 yards, you barely have enough adjustment range to get there (just for the record, a 6-24x40 Elite 4200 that I think I originally recommended would give you 26" of total adjustment range; not much more but enough to make a difference).  You are correct on the number of clicks, but the scopes adjustment range is typically measured in inches of adjustment at 100 yards, and you can translate it to the number of clicks as necessary (incidentally, that pretty much matches the number of MOA of adjustments which some people prefer).

 

Your best way to go at this point is to sell your Leupold rings and get a set of Burris Signature rings:

 

http://www.riflescopes.com/products/420501/burris_signature_ 1_rings.htm

 

and offset kit http://www.riflescopes.com/products/626019/burris_signature_ pos-align_offset_insert_kit.htm

 

These should work with your bases.  Since these are different rings you can not assume that they will point to the same spot as you current rings, so you first sight in your scope with zero offset inserts that come with the rings.  Once you see where the bullets impact, you'll know which offsets to use and where (or post your results here and we'll help you out).

 

ILya

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/14/2006 at 07:07
JaJoa View Drop Down
Optics GrassHopper
Optics GrassHopper


Joined: April/19/2006
Location: Canada
Status: Offline
Points: 14

 

Ilya,

Thanks so much for the valuable info you provided.I will digest all and

come back as I need to.

 

JJ

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/15/2006 at 07:17
JaJoa View Drop Down
Optics GrassHopper
Optics GrassHopper


Joined: April/19/2006
Location: Canada
Status: Offline
Points: 14

ILya,

As I indicated in my last post,I've returned with some further questions or confirmation, on

how to finally site my new scope.

You said..''.Total adjustment range for this scope is 20" at 100 yards (this information is also contained in the documentation that came with the scope).''The Bushnell Manual I got does not show this info!

However,I'm sure glad you provided this important info.

In a previous post I asked''The gradation little lines on the elevation knob are

one sixteenth of an inch, and about seven eights of an inch between the longer

vertical lines.Where do we get one eights of an inch MOA out of this?

Do the one sixteenth of an inch gradation represent one click each time or seven eights between the

longer vertical lines?

I appreciate your suggestion to buy the Burris rings and kit but,I just spent $52. for the Leupold ones,

Could I not use shims under the mounts to accomplish the same results? Because looking at the

Burris signature rings and the post align offset insert kit, would seem to just raise the scope in the

rings, in order to gain more elevation adjustment? Thanks again for any help,much appreciated.

Jacques

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/15/2006 at 11:02
koshkin View Drop Down
MODERATOR
MODERATOR
Avatar
Dark Lord of Optics

Joined: June/15/2004
Location: United States
Status: Offline
Points: 10963

You can use shims under the base if that is easier for you.  In your case, if you are shooting low, you'd want to put a 0.010" shim under the rear base.  Some people would actually put a slightly thicker shim, in case you want to have more "UP" adjustment available.  Perhaps, something on the order of 0.015" is more appropriate.

 

I am suprised Bushnell manual does not show this.  I'll check in my manual for it to see it is there.  The basic specs are available from a number of sources though, such as Bushnell website:

 

http://bushnell.com/products/riflescopes/specs/42-8324m.cfm

 

As for the knobs, a click is called a click because it makes an audible and tactile click when you turn the knob.  One of those clicks will adjust your POI 1/8" of an inch.  I do not have the scope in front of me (I can look at it when I get home), but I would expect that one little gradation line would correspond to one click. 

 

ILya

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/16/2006 at 07:15
JaJoa View Drop Down
Optics GrassHopper
Optics GrassHopper


Joined: April/19/2006
Location: Canada
Status: Offline
Points: 14

ILya,

I had already downloaded the Bushnell manual a while back.It showed

exactly the same info as the booklet I got with the rfle scope.The 20''

elevation @ 100 yards info,however is indicated in their advertizement

specs.Yesterday I removed the scope from the gun,and really studied

and checked the whole thing.The elevation knob has a range of 0 to 5.

For instance 0 to 1 has 48 clicks,and multiplied by 5,I counted 190.

The windage knob had 210.So my 9'' low problem at 100 yards can

be adjusted by clicking up 72 times,which still leaves plenty of clicks

if I need to adjust it higher,say at 200 yards! Does this make sense?

I'm glad to see,that you agree that the shims thing is a possibility!

However,from what I discovered,I might not need to do this.I'm

going to do some shooting and test this out.Thanks again.

 

Jacques

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/16/2006 at 12:33
koshkin View Drop Down
MODERATOR
MODERATOR
Avatar
Dark Lord of Optics

Joined: June/15/2004
Location: United States
Status: Offline
Points: 10963

You should have a total adjustment range of 160 clicks.  If you are currently at the mechanical center of your scope, then you have 80 clicks of "up" left.  9" is 72 clicks.  That would take very close to the limit of the adjustment.  Personally, I do not like to operate a scope right at the edge of the adjustment range.  If I were you I'd put a shim in.

 

I am not sure where the 190 and 210 clicks come from, but it is usually a good practice to try to keep the scope from being too close to the adjustment limit.

 

ILya

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/17/2006 at 06:36
JaJoa View Drop Down
Optics GrassHopper
Optics GrassHopper


Joined: April/19/2006
Location: Canada
Status: Offline
Points: 14

IIya,

I will certainly consider getting shims,as you suggest.But I'm curious as to how

shims under the rear mount (as you indicated in a previous post) would help

the elevation! I would think it would be the other way around.Shim the front mount!

 About the clicks I was wrong,I counted them again and both the Elevation and

Windage knobs, each have 212.I'm very meticulous that way..hi hi hi.

 

Jacques

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/17/2006 at 11:31
koshkin View Drop Down
MODERATOR
MODERATOR
Avatar
Dark Lord of Optics

Joined: June/15/2004
Location: United States
Status: Offline
Points: 10963

That implies that you have just over 26" of adjustment at 100 yards.  However, in my experience, many scopes do not track well at the limit of their adjustment range.

 

Anyhow, you are currently shooting 9" low, right?  That can be rephrased in the following way (this is not strictly correct due to a curved bullet trajectory, but it will serve to illustrate the argument):  your scope is pointing 9" higher than your rifle.  Therefore, in order to bring the point of impact and point of aim to the same spot, you have to make the scope point 9" lower with respect to where the rifle is pointing.  In order to do that, you should keep the fron ring the same and elevate the rear ring a little.  For most standard length actions, raising the rear ring by 0.010" will lower the point of aim by ~10" at 100 yards.  Hence you should add a shim to the rear base.

 

ILya

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/18/2006 at 07:08
JaJoa View Drop Down
Optics GrassHopper
Optics GrassHopper


Joined: April/19/2006
Location: Canada
Status: Offline
Points: 14

ILya,

I agree,I would'nt dare come close to adjust the scope at it's elevation limit,

as I observed while counting the clicks before (212 of them),the knob got

stiffer to turn.

Your explanation of the shims thing,is very clear and informative,and I

thank you for all the tips and info you provided so far.I will do some

target shooting and let you know how it went.

 

Jacques

 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Similar Threads: "Bushnell 8-32x40 scope problem"
Subject Author Forum Replies Last Post
Bushnell 4200 Elite 8-32x40 major accuracy problem Doodaddy Rifle Scopes 1
Bushnell 8-32x40 mm scope JaJoa Varmint Scopes 12 5/6/2006 6:48:12 AM
Bushnell Elite Spotting scope question? bergbennett Spotting Scopes 1
Redfield scope problems BDA103 Rifle Scopes 18
Proper Bushnell rifle scope hackneykermit Rifle Scopes 0
A plea to Bushnell for the 4500/3500 scopes Roy Finn Rifle Scopes 12
Old scope - New problem Dawgdad Rifle Scopes 5
Problem sighting in scope chadfite Rifle Scopes 1
Dating Older Bushnell Scopes 64dodge Rifle Scopes 7
New Bushnell 4500 Elite Scopes lewwetzel Rifle Scopes 14


This page was generated in 0.516 seconds.