[tallpaulg]

My son (sharpshooter, many 1 shot 1 kill awards) and I (old, bad eyes) have an ongoing disagreement. I am hoping I can get some support for my side of this. He is military trained and as mentioned an expert.

He says that each individual may have a different sight picture and therefore a different sight adjustment.

I say geometry is geometry and if the theoritical rifle is sighted in perfectly via vice and laser (or some such) and every shooter holds the "correct" sight picture the result will be the same for all. I am unable to understand his side or debate to a win on my assertation.

An example of his point was made yesterday at the firing range. A .22 CZ was being sighted in, me helping a less experienced friend. When I finally got the rifle shooting tight groups in the 10 ring he tried it and was consistantly shooting the correct elevation but 2" right. I blamed his trigger pull.

We adjusted the sights 2" left and he was consistantly in the 10 while I was 2" left.

Come on now did we adjust for his trigger pull or can 2 people really see differently???????????

 

[JPBeck]

Your son, is right, and being a "sniper" he should be able to explain this to you in better detail than my explanation.

It's called
Parallax Error...

Parallax is the error in apparent point of aim verses actual point of aim due to misalignment of the shooter's eye verses the scope's axis (line along the bore of the rifle). Scopes can be made to correct this problem. Scopes correct this by either having an adjustable or fixed parallax. Fixed parallax means the distance at which there is no "error" is fixed to something for example:
100 or 200 yards from the factory (who ever made the scope). Most "tactical scopes" have an adjustable parallax, which means the user can adjust the parallax error free distance on the fly to reduce parallax error whatever the current target's distance. Finding the parallax is important -- hitting a 4" target at 400 will seem impossible even if you have the correct dope dialed in if your parallax is off.

There are many factors besides geometry-- proper check weld, consistent ammo, wind conditions at target site, firing site, and everything in between-- weather conditions, heat from the barrel, the list goes on and on.

PM me if you want a more detailed explanation and how a scope corrects the problem plus the different conditions that effect shot placement. I'll get you pointed you in the right direction. You can take the info and impress "your one shot one kill" son .

 

[Jay]

A theoretically perfect sight picture would result in the same point of impact for multiple shooters only if EVERYTHING that came into contact with the rifle was EXACTLY the same for each shooter. how the rifle was supported, pulled into the shoulder, trigger finger position, trigger pull, breathing....... there are many opportunities to introduce influences that will affect the point of impact from shooter-to-shooter.

..... just my two cents worth......

 

[dragunovsks]

Yeah, I totally agree, but I don't think it has anything to do with how the two of you see differently. I'm no expert so I might be wrong, but I think it has to do with you. Not YOU in particular, but the shooter I mean.

To give an example, when I bought my AR (standard AR-15A2 with solid stock) a few months ago, I talked my wife into shooting it. After showing her how to hold it and how to line up the sights she said that she just couldn't get the stock into the pocket of her shoulder like she needed to. I was going to get an AR with an adjustable stock so she could shoot it but found this one cheaper. Her arms just weren't long enough to use it correctly.

I have also fired her dads Marlin 30/30 with scope mounted an wasn't as accurate as him cause the scope was sighted in for him. Likewise, he isn't as accurate with my semi-auto .22LR either.

Like I said before, I'm no expert and this is just my opinion and personal experience and you can take it for what it's worth, a grain of sand and 2 cents.

 

[cpttango30]

no two people can hold the exact same sight picture because no two people are exactly the same.

I don't believe the scope was sighted for him thing. Why I grew up shooting rifles that were sighted in for another person and not once did I ever have a problem with shooting. With optics it makes little to no difference who sights it in. You have to be very close to the same sight picture becuase if you are not the image in the scope will not look the same.

Then again I can't count how many times I picked up a persons M-16 in the Army and took it out and fired a perfect 40 out of 40 with making not a single adjustments to it. I even got accused of cheating once because I was not allowed to fire until the very last relay. I just grabbed a closest m-16 and went out to the line and laid down another perfect 40 out of 40. The person I took the rifle from said I must have been cheating because there is no way to shoot that good with a weapon not sighted for me.

I also did something similar to this with the M9. With that you get 40 shots to hit 30 targets. You know tankers and officers need a little help. I fired a perfect 30 out of 30 but I had 12 round left over. I watched and noticed that if you were standing in the right position you could kill two commie joe's with one shot. I did that twice.

If you are a good shot then you are a good shot. It may take me one or two shots but after that I know where your weapon or firearm is shooting for me so I just make a slight adjustment in my sight picture to give me what I want.

I think if you are "less accurate" with a scoped firearm it is just in your head because you think you are going to do bad so you do.