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Thursday, January 1, 2015

Rimfire Scopes


A compact one inch scope seems appropriate on this small youth rifle.

The rimfire scopes and air rifle scopes are not too different from the centerfire scopes used for deer... If you choose the wrong scope it won't matter how good the quality or the brand-name you won't have the best.

What is different when choosing a rimfire scope?

  • Small game and pest offer a smaller target. 
  • Often they are at shorter range. 
  • Rimfire rifles have very little recoil.
  • Some air rifles have reverse recoil.
  • You could want parallax correction. 
  • The guns can be smaller and lighter.

A smaller target may suggest more magnification, but I caution you only slightly more magnification. Excessive magnification leads to more magnified movement, less field of view, shorter depth of field, less bright optics, and/or bigger scopes with bigger objective lenses.

If one magnification was offered most would suggest 4x. The 4x works for big game, small game, and most other uses. Sometimes it's a little too much for close up moving shots. Less often we need more magnification when we can't stalk any closer.  For small game the ranges are shorter, but the target is smaller so it often works out about the same. My point is that 4x is simple and most often it works fine.

The .22 long rifle is still the most popular rimfire. Small game and pest are usually shot at 50 yards or less. A 2-7x30 or 3-9x30 variable of decent quality makes sense. For small running targets at close range the 2x could be slightly better. For longer shots with good light and a solid rest the 9x could be slightly better.

The hot .17s, Winchester .17 Super Mag and .17 HMR have extended the rimfire's range. They offer a higher velocity, flatter trajectory (less bullet drop), and sometimes better accuracy. For all around shooting of small game and varmints with the hot .17's a 3-9x30 or 40 would be my choice. For more specialized small pest (ground squirrels maybe) and varmints at the max range a 4x12x40 could be in order.

Air rifles are still generally less capable than a rimfire. BUT! Good air gunners often get into precision shooting. Many enjoy plinking at very small targets, insects... While more typical air gunners use a 4x30 or 2-7x30. If your into precision shooting with a fine accurate gun you could want a 3-9x40PA or even 4-12x40AO. (I'll explain the PA & AO later.)

Recoil is not a problem with a rimfire and you can sometimes watch the bullet strike the target. Any good quality scope will not be affected by the recoil of a rimfire. Some air rifles however can require a scope made specifically for them.

Spring piston air rifles have reverse recoil. Don't put a fine quality $1000.00 scope on a spring piston air rifle. Even if it's designed for elephant rifles it may not be able to take the recoil from the opposite direction.  You need a scope designed for these air rifles.

Tube size:  Most scopes have a one inch tube diameter, but a few inexpensive air gun or rimfire models have smaller 3/4 or 7/8 inch tubes.  They work, but not very well.  I wouldn't recommend these cheap small tube scopes.

Scopes labeling: 4x30, 2-7x30, 3-9x40PA, 4-12x50AO... The first number indicates how much the image is magnified; for example a 4x will make the image appear 4 times larger. A 2-7x variable (zoom) can magnify the image 2 times or a ring can be turned to vary the magnification up to 7 times on that scope.

The x30, x40, x50 is the diameter of the objective lens bell or front lens of the scope. That objective lens size should be about 5 times the maximum magnification power of the scope. If the objective lens is less than five times the maximum magnification, it will work fine in strong light, but appear dark at dawn or dusk.

There is no serious advantage to such a big scope in normal light or at the low and middle zoom settings on a scope. Such big scopes can't be mounted low, they can look awkward especially on a smaller rifle, and they can unbalance smaller, lighter rifles.

PA or AO Sometimes the x40 or x50 is followed by the letters PA (Parallax Adjustable), or AO (Adjustable Objective Lens) which do the same thing.

To demonstrate parallax point your finger at an object across the room, close one eye, and then the other. You lined up the object using your dominant eye, and when you close the other eye, it's not lined up. This is a simple but dramatic example of parallax.

Rimfire scopes are set to be free of parallax at a typical rimfire use range (50 yds. maybe). Centerfire scopes at a longer but typical centerfire use range (maybe 150 yards). Both are compromises, but work fine for most use. Many hunters don't even know about parallax.

AO scopes allow you to adjust or focus for more precision shooting at the range of each shot. I've owned a few and my opinion is, "Most shooters shouldn't loose any sleep over parallax or having a PA scope."

If you get to be a precision air rifle shooter you may want one, but I've set mine for 20 yards, then forgot and used it on that setting for much longer shots, some I made, some I missed, the same as with no PA. Now I most often set it at a compromise range for the hunt and I often forget about it.

What else is needed in rimfire scopes; I believe very little. I like crosshairs which taper or step from thicker to thinner toward the center. The thick part is easier to see quickly, and the eye goes naturally to the central or fine aiming point which doesn't cover or hide too much of a small target. Most scopes now come with something like what I just described.

$ Money: I do believe money can buy quality up to a point, after that it only buys some possible prestige in the owners mind.

I don't feel the rimfire (or other) scopes need lighted crosshairs, bullet drop computation, or other such things. They only clutter and add to the confusion and sometimes at a critical moment; again my opinion.

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