What is side focus parallax adjustment (riflescope)?

[driftak]

Wondering exactly what this is about. Any hunters use this feature, or is it more of a target feature? Leupold offers it on their long range model riflescopes. Would like to hear explanations/experiences with using this feature in long range shooting performance. Thanks.

[driftak]

Either nobody knows, or this is a dumb question. Sure a lot of talk on here about brands - wish there was more useful information about optics. I'll look elsewhere.

[Smitty of the North]

Parallax ---An apparent change in the direction of an object, caused by a change in observational position that provides a new line of sight.---

This is the best as I can explain it, let alone understand it.

Parallax is set to a particular range, normally 125 yards, for most riflescopes, 75 yards for Shotgun Scopes, like up to maybe 9X.

For higher power scopes, there can be an adjustment to eliminate error from parallax if your eye isn't centered on the reticule. (You can move your eye to the right or left, and still have your crosshairs on the target, but your sighting will be off.)

Sometimes the adjustment is turning the front lense, and on others, there is a knob on the side.

I have a 4X to 12 scope, and I can see better at 12X if I have the parallax adjusted for the particular range.

The other scopes I use, 4X, 2X7, and 3X9, don't have Parallax adjustment. I'm told it's not needed.

The above is probably a poor explanation, and maybe even not quite correct, but again, it's the best I can do.

Smitty of the North

[morgan]

Parallax is the apparent movement of the reticle on the target as the shooter moves his head up and down, side to side.

We used this in sniper school to tighten up or groupings. The first thing I did after acquiring a target is to check my parallax. I would put the gun into position, then lift my head off the stock moving my head up and down. I would continue to do this while adjusting the side parallax knob until the reticle stopped bouncing up and down on the target and they began to move in unison.

It's a bit hard to explain until you get out and try it for yourself. Some students had a very hard time distinguishing the movement while others who caught on were able to bring their shot groups into sub MOA groups. You'll notice it more when moving a couple hundred meters between targets.

Hope this helps a little. Not too many hunters use this feature as it is more noticeable at greater distances, say 300 to 800+ meters.


Morgan

[sweepint]

I have this feature on my leupold mark4 it is much more useful on the range at 300 and on out to 800plus. It was a bit of a fine tuning for longer range targets. We used to see this on the older scopes and it was on the end of the scope tube. It did become more popular on sniper rifles for ease of movment. I dont think that it is a must have on a hunting rifle unless your doing long shoots from a very stable platform. I hope this helps.

[driftak]

Interesting. I've never had a scope where parallax could be adjusted, but thinking of trying one on a long range rig (ultra mag) mostly for fun, but concerned that the feature might get in the way somehow when out hunting in the field with it. (Dual purpose) In other words, if you had the feature, do you have to adjust before each shot, or could you choose to ignore it for shots say 0 to 400 yards with negligible affect on accuracy? I'm also needing a bit more power, fine x-hairs, and I think the combo could work well out at 1000yd or so.

[sweepint]

It would work as a hunting scope with little effect out to 400 yds.
Now as for a hunting scope for ranges out to 1000yd, that is a hole diffrent animal. Your talking about a scope like a leupoLd mark 4 with target turets that have 1/2 MOA windage and a 1MOA elavation.

Sure you can use it and carry it out in the field. larger scope with high turet knobs to catch on everything. There is other variable for long shots out to those ranges, its not just the glass that gets the bullet out there. the average rifle is not a 1/2 moa gun, its more of a 1moa and by the time you push the bullet out to 600 yds that gun at its best is a 6 or 8 inch group with out human error. I think i am getting a bit deeper that you were wanting. IF so sorry, just my 2 cents