he said they never used scopes with a higher magnification than 10 power. He said that any greater than that and the scope starts to pick up mirage and is therefore less accurate. This gentleman was not particularly young, appeared to have been pretty involved in the sniping world for a few decades, and had most recently spent some time in Afghanistan. I trust that he knows what he's talking about. But I wonder if anyone else has any thoughts.
Well yeah, I have thoughts on the subject.
I've been to sniper school, trained as a (peace time) Mil Sniper and worked as a LE sniper, and conducted untold sniper schools, military and LE.
Added to that I have over 35 years shooting long range competition, and coached NG Rifle Team.
So yeah I have thoughts on the subject, My experience tells me your friend is 100% correct.
Before the Army, Marines, Secrect Service, FBI and tons of other local LE sniper schools came about the US Amry Marksmanship Unit conducted sniper schools, mainly with the goal of their graduates go back to their respective unit or department to start their own programs.
That is what happened in the case of the Army, Marines, NG, SS and FBI as well others including the Alaska NG who's program I developed.
The number one recommended glass for the LE sniper per the USAMU was a fixed 6X.
When I started teaching sniper schools the guard was using M1C/Ds with their 2.2 X M-84 scopes............they worked to 900 yards.
When I coached the AK NG Rifle team we had a 100 MM team scope that came with 16 - 32 Power eye pieces. I found (as most coaches) for a spotting scope 20-24 power is the best. Many of my shooters kept putting the 32X in the scope thinking it would be better. I finely had to toss that scope in the trash.
Too much power does in fact pick up too much mirage and washes out the target. Mirage is a great tool, but you need to look at the mirage not the target to use mirage to check wind conditions. With a scope you need to see the target not mirage.
Thats why we have spotting scopes. Focus it between 1/2 to 2/3s distance between you and the target. Focus your rifle scope on the target.
One other thing that must be addressed and that is heat from the barrel. Many people wrongly think you can use the scope to focus on the mirage to get a reading then focus back to the target to shoot. That's time consuming since it takes an instant for the wind to switch.
Plus, when using a rifle scope you get interference or heat waves coming off the barrel giving you a false reading, you can't tell if you're reading the mirage or heat waves on the barrel.
I use a barrel band, or an elastic band that stretches from the rear sight to the front sight to break up heat waves coming off the barrel.
For my 1000 yard rifle I use a Weaver T-10. I do have a couple scopes that go higher, one is a 3-12 weaver and I do have to use the 12 power to get the Mil Dots to work. I also have a 6-18 varment scope on my 204 Ruger #1. My wife bought that scope but it isn't too bad for PDs, but I don't often use the higher ranges.
I also have a Remington 24X scope on a 22 target rifle, but that's a short range gun (50 ft to 50 Meters), there's not much mirage there.
So yes I agree with your friend.