Adjusting scope for parallax

[tazzman]

Hi everyone,

Scope adjustment is a touchy subject. We are all looking to guarantee that what we see in the scope is the best image possible so that we can do our best to shoot the bull's eye. I, for one, believe that the simplest (please read that it is not necessarily the shortest) explanation is always the best one. I am not an engineer, nor am I versed in the intrinsicacies of the English language. I enjoy reading about shooting experiences and especially condone the ones where I can read, understand and duplicate the results of your(and I'm including all of you) results, where possible. My eyesight is not the best. I also enjoy shooting short-range RF benchrest with a BR-36X Leupold FCH(fine cross-hair) reticle. I also admit that, some days, that reticle is harder to acquire than better days. It is something I have to live with. All this being said, I would appreciate a point-by-point procedure that ensures a positive result for the majority of shooters. I am not looking for the Holy Grail. Just the explanation that will work for me. Belief in one's own process is good, but not to the detriment of others. I am looking for a response that will improve my performance, and I imagine that most of you do too. Let's write/read the following responses without making denigrating comments.

Just my .02( read .04 with the current exchange) cents worth.

Phil aka tazzman

 

[Tozguy]

Up to now I have always worn my prescription glasses to shoot but there is a problem with that. They are graduated for reading to 3.25. It takes very little head tilt to 'adjust' my vision. It is very difficult to keep exactly the same head position for every shot with the free recoil technique so I find myself hunting for the best head position every shot. I can never be sure if its me or the scope that needs adjustment. Based on some comments in this thread I tried using non prescription safety glasses and using the scope's ocular and objective adjustments to correct for my vision. It seems much better this way and a lot less frustrating to aim.

 

[BoydAllen]

When I got my first bifocals i got some good advice. Dr. Fong advised me to go with line type bifocals, with the line low on the lens, which keeps them out of the way, but well placed for reading. They work just fine, and there are no issues when shooting through a scope.

 

[Tozguy]

BoydAllen,
When I first started to wear reading glasses they were bifocals, with the line seperating the two partsof the lens. Then I needed trifocals and eventually my optometrist recommended graduated lens instead of having several lines in my vision. These are definitely excellent for everyday use and I only take them off before going to bed. I have a different pair of glasses for motorcycle riding because my head posture requires a different lens position. There is also a third pair of glasses for when I have to see up close in awkward positions. I asked my optometrist about a special prescription for shooting but it was expensive and I could not justify the cost of another pair of glasses. It turns out that using the scope adjustments to correct my eyesight when shooting is a perfectly feasable alternative at this point for me.

 

[Fred Bohl]

On the other hand I have seen the results of several blowups that turned the shooter' s face into a pattern of small cuts that would have extended into the eyes if glasses had not been worn. IMO really bad advice. :-[

Having been the president of a large range that was open to the public and members seven days a week, I can speak with some authority on the subject of length of shooting experience and attitude about strict compliance with range rules, including safety procedures. Many times they do not correlate.

After long and careful consideration, I have decided to reply to your above comments. I do not intend this to be "mean spirited" as I do respect your opinions even those with which I disagree.

Please note that my comments on use of corrective eye wear were preceded by the "IMHO" (In My Humble Opinion) that from common usage on this forum is intended to mean that what follows is my own opinion based on my experience. I did not offer or intend those comments as advice or I would have started with something direct like "You should try..." or even "You might try..." instead.

Since you chose to provide "credentials" via your range history to support your critique of my opinion, I offer the following:

For the last 10 years I have put in 400 to 500 hours per year as a volunteer Range Safety Officer at our range which is open to public. Our policy is to recommend but not require eye and ear protection on the advice of our insurance company. Note that they advise us that to require these protections, we would be compelled to make such protection available in a type certified to be effective for the purpose.

I personally lost the hearing in one ear, some damage to one eye and other injuries in combat due to a very nearby detonation of an enemy RPG while purportedly defending the personal liberties of myself and all US citizens. Note that the US Government did not find it necessary to suggest or provide any eye or ear protection nor at that time any body armour.

Sir, I inferred from your second paragraph that you meant to imply that my experience and age somehow led to my being disrespectful of your understanding of commonly accepted safety rules and practices. If that was your intent I find that to be offensive to my service and sacrifice and to our personal freedoms I fought to defend. If that was not your intent, then I would suggest (this is advice) that you make your intent clear and chose your target more carefully in the future.

 

[BoydAllen]

Fred,
Of course I would never disrespect you service. Until you wrote of it, I would have had no way to know about it, so I am surprised that you would take it that way. My second paragraph was a reaction to years of my own experience dealing with a minority of experienced shooters who argued against having to wear eye protection on a range that required it. If I were to disrespect anything, it would be an insurance company that would take the position that yours has. One thing that I have learned, over the years, is that many people ( I am not speaking of you here.) are real dummies about eye safety. It is not that I have always been any better, but simply that having to wear glasses has saved my eyes from damage on more than one occasion. After a number of years of seeing "could have beens" it has finally dawned on me that there are many tasks where some form of eye and/or hearing protection are appropriate. In an effort to reduce the number of injuries related to a hobby that I find myself writing about, I have, and continue to, take a strong position on eye and ear protection, in the hopes that some readers may be influenced to take better care of themselves. That is all my post was about. I have the warmest respect for both veterans and volunteer range officers. The range that I currently belong to is staffed that way, and I am proud to contribute a little of my time as a RSO. Be well.
Boyd

 

[Fred Bohl]

Boyd,

I appreciate your quick reply and the clarification it provides. Be assured that I did not take your comments to be intended as a personal attack on me.

Maybe the occurrence of Veterans Day between your first post and my reply this morning contributed to my misinterpreting your comment and inferring something that wasn't there.

I also support encouraging use of effective eye and ear protection in shooting sports as elsewhere. Both the gun club and I actively support the Hunter Education Courses here in Wisconsin including the mandatory use of eye and ear protection by minors during range activities.

However, I still believe that adults are free to do their own risk benefit analysis and make their own choices as to use of equipment and procedures for their personal protection as long as such choices do not endanger others.

Happy Thanksgiving Day to you and yours Boyd.

 

[TnTom]

Some interesting discussion going on. (1) properly adjusting for focus and parallax error and (2) should one wear eye protection. (3) with corrective lens on or off.

I have found that consistency seems to play an important role. I have learned if I screw something up the same way each and every time the results become predictable.

Focus and Parallax, I adjust the focus against the sky and adjust my AO until I have no parallax error. I tape my obj ring and mark it accordingly so its one stop shopping adjusting for no parallax at a given distance. No deviation involved.

I always wear eye protection when working up a new load. . I always put them on if I have another shooter near me. Doesn't guarantee I wont lose an eye but provides some margin of safety. I always wear my corrective lens (which just happen to be safety glasses). It works for me so I do it.

I have never found a reason to do it any other way. It may not be correct but it works for me.

I use fixed power scopes and don't mess with variables it just makes it easier to remain consistent.