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mesabi
December 21, 2010, 02:16 AM
I have a CZ 452 American in .22LR. It group very well but when I aim at different points on a target, the groups tend to go more in that direction from the center. If I shoot at center target, it is dead on. Top left target it shoots high and left. Lower left it shoots low and left.

The barrel is floated about an inch in front of the muzzle. I shoot only standard and subsonic ammunition. I have a Mueller APV 4.5-14AO mounted in CZ rings. I installed an aftermarket trigger kit.

Anyone have any ideas as to what is going on? I think it has something to do with the scope. I have shot a lot of different ammo but never noticed it until it got sighted in. Any ideas or suggestions?

Win_94
December 21, 2010, 02:39 AM
My comment may sound like a "flame" but it isn't one.

It is either psychosomatic, or too small of a test sample to draw the conclusions arrived at.

ADIDAS69
December 21, 2010, 03:36 AM
...has a point. if you really want to see if it is you or the scope. try this test. in order to hit the other points on the target use your windage and elevation to move you impact point. continue to aim at the EXACT same spot. it sounds odd, but consistency is the only thing that matters. if it turns out to be you the only thing i can suggest is practice. if it is the scope ( its not the scope ), light may be entering the objective in such a way as to make the center of the intended target appear to be under the center of the reticule. If your scope is really messed up then you need a better scope.

Try the Aguila 60 grn subsonic if you're still having issues.

madcratebuilder
December 21, 2010, 07:33 AM
The Muller APV is a very good rimfire scope. Lot of very good shooters at rimfirecentral use the APV and I sure don't recall any problems you speak of. I've had mine on the same rifle for four years and it tracks perfectly.

Art Eatman
December 21, 2010, 08:54 AM
Just sorta off the cuff, but it sounds like a shooter problem with parallax. Eye-position not centered in the scope...

Just a guess...

4runnerman
December 21, 2010, 10:11 AM
Art you beat me to the punch . :) What kind of scope do you have on it?.
If it is a variable scope turn it to lowest power and try test again. Had same issue this summer and found out( i knew already) i had a very cheap scope.

thesheepdog
December 21, 2010, 10:24 AM
Sounds like you're not shifting your "Natural Point Of Aim".

To do this, simply place your crosshairs/sights on the next target; close your eyes and breathe in and out naturally; open your eyes and see where your crosshairs are pointing now. If they're on the center of your target, then you have found your natural point of aim. If not, then you need to shift your body and repeat the steps over again till your shooting position naturally rests on the center of your target.

Also watch your crosshairs as you breathe. If they move straight up and down, then you have NPOA. If they move at an angle, then you do not have NPOA.

mesabi
December 21, 2010, 02:16 PM
I tried the 60 grain subsonics, rifle did not like them at all.

I will try that hopefully next week sheep.

madcrate, I saw the same thing at rimfire central, I am not going to rule it out as a possibility though.

Is there any way of checking if my eye is centered in the scope? I positioned the scope so that when I pull the rifle up I do not need to move my head forward or back any to get a full clear image.

I will give that a shot Adidas. Convinced it's not the scope?

thesheepdog
December 21, 2010, 02:29 PM
Is there any way of checking if my eye is centered in the scope?

Yes. If you have any shadow on the edges of the objective, you'll not be aligned.
Basically, if you can only see some of your reticle on the scope, you don't have proper eye relief/alignment.

mesabi
December 21, 2010, 02:48 PM
My head is properly aligned then. I cannot for the life of me remember ever puting my finger on the trigger with any shadows or blurs around the edges.

thesheepdog
December 21, 2010, 03:14 PM
I highly recommend you check your NPOA while switching to another target.

What happens is you get into a nice position and go through several steps before taking the shot:

1) Sight alignment.
2) Sight picture.
3) Respiratory pause.
4a) Focusing your eye on the front sight.
4b) Focusing your mind on keeping the front sight aligned with the target.
5) Squeeze the trigger
6a) Follow through by holding the trigger back until the round has exited the barrel.
6b) Take a mental snapshot of where the crosshairs were on the target, when the round went off (call the shot).

Now if you're aiming at a target with 5 squares (one in the middle and one for each corner) you will of course aim for one of them. But when you decide to switch to another square, you can't simply just sweep the barrel over and expect to have NPOA on that target.

NPOA is basically your relaxed shooting position. And if that position isn't aligned with the target, you won't be hitting it. You will have tight groups, but you won't hit your desired "point of aim".
This happens because your body relaxes and when you try to move your sights without moving your body, your shots will be off. It's kinda like straining your body out of it's natural shooting position when you don't shift for a new NPOA. Imagine yourself glued in your natural shooting position, and then trying to switch to another target. You can't move your shot, unless your whole natural shooting position moves with you.

mesabi
December 22, 2010, 01:09 AM
Thank you sheepdog. That was very informative. I try my best to go over the checklists before shooting, but I will be sure to print this off and take it to the range with me. I think the indoor range back home is still open. The instructor there may be able to watch me and make sure I am not doing anything wrong.

Jimro
December 22, 2010, 02:05 AM
My first thought was parallax. Your scope has an adjustable objective, have you dialed it in to ensure that you are parallax free at the distance you are shooting?

Jimro

Scorch
December 22, 2010, 02:21 AM
sounds like a shooter problem with parallax. Eye-position not centered in the scope
Bingo! Cheek weld!

thesheepdog
December 22, 2010, 11:07 AM
As others have mentioned, check your cheek weld.
Make sure you have a seady platform to shoot from, then follow those six steps I gave you.

mesabi
December 22, 2010, 02:16 PM
I am shooting at 50 yards. Objective is set at 50 yards.

I am shooting off a bench set up at the range. I use a bipod with a rear bag. I bring my left hand back and place the buttstock between my thumb and my index finger. If I need a lower point of aim, I force my hand more underneath the stock. I put front pressure on the bipod by pushing forward with my shoulder with the legs being caught in a 2x4 higher than the others. Could that cause problems?

Besides not having any black or blur around the edges, how else can I check eye alignment?

I also use a three finger grip with my right hand. Ring, middle, and index on the grip, little finger is curled under the grip. I read about having as straight a pull as one can get with the trigger finger and that gives me the straightest pull. I have a moderate grip on the rifle. I do not squeeze hard, or have a weak grip.

I have a light trigger pull. I shoot with empty lungs. I exhale, pause for no more than about three seconds, shoot, and hold for a count of two. I

Anyone have some tips based off that?

woodguru
December 22, 2010, 02:31 PM
..to find exact center.

Move your head from right to left until you can see where the edge of the scope wants to shadow out from your head being too far from center. The range of right to left movement will also give you an idea of where the exact center position is. Do the same up and down.

Once you have that feel for dead center of the sight field make sure that your cheek position (cheek to stock) locks tight and repetitively and that you are moving the whole rifle when you shift to another target and not leaning your face and eye to acquire the off center targets.

It's actually easy off bags to have a center target straight and move your head into a different position as you want to acquire an off center target. Your head repositions easier than a rifle does.

As mentioned by several others it does seem to be the position of your eye being off true center, scopes will allow slight off center eye position that changes the point of aim.

Now the really facetious answer was shoot a target with one spot if the others are going off, duh. :D

Picher
December 22, 2010, 02:56 PM
I suspect the bipod as the culprit. You may be putting torque on the legs by moving the rifle. That can change the point of impact, especially if the forend is twisted enough to contact the barrel.

It doesn't make sense that the scope would noticeably change the POI, but even on sandbags, we find a slight difference in POI as targets are shot left and right of center if the rifle's forend is binding in the front bag.