What is a Mil-Dot scope?: December 31, 2007

Next, is an article by Tom Gaylord who again is probably theee authority on air guns. Tom has forgotten more about air guns than most of us will ever know. First of all, we have to know what a “mil” is…. Dirt E. Harry

Do you REALLY NEED AO?: December 30, 2007

Well, no, you can get by without it, if need be. In fact, you can get by with open sights, if a scope isn’t in your budget. But, if you are contemplating a future scope purchase, I recommend that you consider saving a little longer until you can afford a scope that has AO. It makes your shooting that much better!

In the meantime, until you get a scope with AO, here is what to do. Practice mounting the rifle in the same way every time, so your face contacts the stock at exactly the same place, shot after shot. That way you will reduce whatever parallax error your non-AO scope has, and you will get the best accuracy possible under the circumstances. Dirt E. Harry

Ranges are not always exact: December 29, 2007

Temperature affects optics by making them expand or contract. Since optical tolerances are measured in units smaller than one-millionth of an inch, any change in dimensions will affect how the optic works. In the case of parallax correction, the scale of yards will change with the temperature. So the number 20 on your AO scale could really represent 19 yards today and 23 yards next week, if the temperature fluctuates that much. Field target competitors compensate for this change by having three different color-coded range scales on their adjustment wheels, but you don’t need to. Unless you are concerned by your pellet striking one-tenth of an inch away from the aim point at 30 yards, the scale on your parallax ring or wheel is good enough for all shooting. Just understand that the measured distance will not always be the exact distance for this reason. Now you know what AO stands for. Even though many scopes with parallax correction are now using side adjustment knobs, the marketplace still uses the term AO to mean all scopes with parallax correction. Dirt E. Harry

The Mace Pepper Pistol: December 28, 2007

I am proud to announce that the Mace Pepper Pistol is now online. Just Point and Shoot! This lightweight pistol does not spray the pepper (OC) solution, it shoots the pepper in the form of a streaming blast so that you don’t have to! Weighing only 8.6 ounces (loaded), you can drop a would be assailant like a bad habit. You can even shoot across the wind with no fear of blow back danger. Dirt E. Harry

Larger knobs, or sidewheels, make for more precise adjustments: December 27, 2007

By making the adjustment knob very large, a shooter can place white tape around the rim of the knob and write in the actual distance figures, as actually measured on a range! Because the adjustment wheel is on the side of the rifle instead of on the scope objective bell it can be very large and still clear the rifle. Marks made on the edge of a large wheel are far enough apart that real precision is possible. An example is the Rex 10-40X50E-SF Scope. Dirt E. Harry

Sidewheel adjustment knobs: December 26, 2007

The sniper scope builders also borrowed something else from airgun scopes, but as yet they have not developed it fully. That feature is a side adjustment knob for parallax. The location makes adjusting parallax easier because the shooter doesn’t have to reach all the out to the end of what is usually a very large scope. The adjustment knob is on the left side of the turret, opposite the windage adjustment knob. Airgun scopes had this feature back in the early 1990s (which is why the term AO isn’t always correct – but who cares?), and ten years ago, shooters began experimenting with the size of the adjustment knob. Dirt E. Harry

Season’s Greetings: December 25, 2007

I just wish everyone a Merry Christmas and a Happy New Year. Dirt E. Harry

Some firearms scopes have parallax correction: December 24, 2007

Not all firearms shooters are cavalier about bullet placement. Tactical snipers, for instance, have to place the bullet exactly or they may not realize their goal. When a suicidal terrorist has his finger on the trigger of a bomb, it matters what happens to that finger after the bullet strikes him, and tactical snipers train for such missions. So optics companies like Leupold borrowed the concept of precision parallax correction from airgun scopes and adapted them to sniper scopes. Dirt E. Harry

Parallax Correction= Rangefinding! December 23, 2007

As it turns out, when a scope corrects for parallax at a given distance, it also focuses the target image as sharp as possible. You don’t notice this at 150 yards, because the image is so small that the details are too difficult to see, but at 30 yards they stand out vividly! So before long airgunners found out they could turn the parallax adjustment ring until the target image was sharp, then read the distance to the target on the parallax ring. Presto!-Instant rangefinding! Distance information is very useful to an airgunners whose pellet may drop five inches out at 50 yards. Many shooters think that’s what the AO feature is there for; they aren’t even aware of the parallax problem. Dirt E. Harry

Back to AO: December 22, 2007

Airgunners strive for accuracy that other shooters never dream of! We want to hit within half a pellet’s diameter at 35 yards! Firearms shooters don’t usually shoot that close, and they don’t think in terms of hitting within 0.09-inches of their aim point! The effects of parallax are greatest at very close range, so by the 1990s, many better airgun scope makers were putting parallax adjustments on their scopes. The shooter then looked through the scope and turned the objective until the target appeared as sharp as possible. When that happened, the parallax error has been reduced as much as possible for that particular target. Dirt E. Harry