Is parallax the problem?

[spikehunter]

So I have a .22 magnum that I am just starting to get sighted in. The scope package says the parallax is set to 50 yards. It shoots hornady 30gr and remington 33gr well. I was getting a tight cluster at 50 yards. When I move back to 100 yards the group spreads out to at least 4 inches. There does seem to be a fair amount of parallax at that distance. Is this normal for a scope set at 50 yards? (its not a high end scope and I'm no expert on parallax)   Could this cause this much variation?  When I get a chance I'm going to try another scope, but I just wanted some imput.

[RED333]

Standing, sitting, prone, bench, bags as a rest, or a rest of some kind?

Dont get me wrong, I am not a good shot, I HAVE to use a rest of some kind to shoot out to 100 yrds.

If you are not using a rest it could be you.

[vujade]

It'll affect accuracy; but I'm not sure to that degree.  My experience was with shooting my Savage 10fp in 308.  My groups were around half an inch or better (100 yards); I had on a Nikon with a really good parallax setting that was dead one (50 yards, 100 yards, etc.).  I changed scopes and it opened up to about .5 to .75 inches.  I then learned about parallax and after i set it properly, groups went back down (and better).

 

Bench the gun, move your head up and down and left and right and forward and back looking through the scope without touching the rifle.  If the crosshairs move, that's the parallax.  Adjust it until it doesn't move anymore.  My mistake was that I was following what the knobs said; it had zero correlation to the actual setting.  I also had the rings too close to the middle part of the scope (where the knobs are and that affected it the parallax setting).

 

The deviation you get as you move your head around is (I think) what you would expect in a different point of impact when you finally pull the trigger.  No movement as you move your head around would mean the same point of impact even if you don't put your check down at the exact same place on the stock for the next shot.

Edited December 13, 2012 by vujade

[spikehunter]

I was shooting off of bags and front rest, but it is a bolt action pistol. Its a little more difficult to shoot. I plan to get a better rest to hold it in place. Also, the scope that I put on it doesn't have parallax adjustments, its just set to 50 yards. I can tell there is considerable movement of the crosshairs when I move my head (at 100 yards), but I think I need to do some better testing.

[Guest nowheretobefound]

If the scope states it's set for 50 yards, that's it, many scopes of lower power, many inexpensive scopes are like that for small cal rifles or pistols. If it was a rifle you could put it back onto or into a firm rest, then without disturbing the rifle (at a 50 yard distance) move your eye around slightly and observe if the cross hairs of the reticle move. If they do check the occular focus again (when you focused the eye piece to your vision) and recheck. If you have the scope focused well for your eye the scope itself could be whacked. And it will be "off" beyond 50 as far as parallax goes. The only thing you could do to lessen the inaccuracy beyond 50 is to have a good cheek weld and be as consistant in cheek weld and eye placement as possible or get another scope. But since it's a bolt action pistol you will not have a cheek weld and you setup is basically for 50 yards or less.