Here is where the concept of "relative eye relief" enters in. "Absolute eye relief" is the actual physical optical measurement of full-view scope-to-eye distance. Relative eye relief is where the mounting position of the scope puts your head in relation to your hold on the gun, and is determined by such factors as the length of the stock, the ring positioning on the mounts, the turret position on the scope, the mounting position of the scope on the receiver, even the thickness of the clothing you're wearing. The same scope can have a long relative eye relief on one gun, and a short relative eye relief on a different gun.

Short-stock rifles require different relative eye-relief position than standard long-stock rifles.

b>Think it through: if you mount a scope on a rifle with a standard-length 14-inch pull stock, and mount the same scope on an identical rifle with a compact or youth-length 13- or 12.75-inch stock, you will find that your relative eye-relief position with your natural shooting hold has changed by exactly that difference. With heavy-recoil guns that difference can be painful.

Whether or not you will be able to position that scope for optimum eye relief with both (or either) rifles depends entirely on the amount of forward/backward position flexibility the mount position and scope configuration allows. Again, the only way to figure it out is to try it out.

Most of us don't pay enough attention to the technicalities of eye relief when choosing or mounting a scope. It's why we've all been whacked by a scope on the eyebrow or bridge of the nose at least once. Most of us also don't pay enough attention to the importance of neck position in response to recoil, and position our scopes much farther forward than we should, which makes us shove our heads forward on the stock to get a full field of view.

By and large we're a nation of stock-crawlers, probably because we all learned to shoot with nonrecoiling .22s. But when you crawl the stock on a recoiling gun, the noncompressible bones in your neck will keep your head in place while your shoulder is pushed backward and the stock slides past your cheek, and the scope will meet your eyebrow or the bridge of your nose with unpleasant effect. If your head is upright relative to the stock, it will move with the stock and the shoulder, and the distance between your eye and the back of the scope will not change.

To avoid unpleasantries, set eye relief for your proper shooting position by assembling your gun and prospective mount system (preferably before you spend your money) and leaving the scope loose enough in the rings to move it freely backward or forward.

Close your shooting eye and shoulder the gun naturally, keeping your head upright and not crawling the stock. Then open your eye. If the scope is not positioned for correct eye relief, move it backward (sometimes forward) until it is. If the mount configuration or scope turret position will not allow that, don't change your shooting position. Instead, use extension rings, a different mount or a different scope. It's your scar tissue.