Izh 7-4 diopter

[conradin]

OK, I can neither read the Russian nor the Altius label helps me.

So which direction (clockwise or anticlockwise) should I dial the right/left knob if my shots ends up too far right of the target?
Also, which direction (clockwise or anticlockwise) should I dial the High/Low knob if my shot ends up too low from the target?

The altius label has R with a clockwise arrow, but what does that really mean??? Dial clockwise to correct a shot that ends up being right of the target? or Dial clockwise if you want your shot to move rightward towards the target?

Confusing..

[crasher]

counter clockwise
left and down

clockwise
right and up

so the top clockwise (up) and the side counter clockwise (move to the left)

[conradin]

counter clockwise
left and down

clockwise
right and up

so the top clockwise (up) and the side counter clockwise (move to the left)

So this is exactly the opposite of Anschutz or most German target rifles? (Turn towards Links means you want the shot to go right, turn towards Rechts means you want the shot to go left!)

[David Levene]

Surely one of the first things you do with any new gun (after cleaning) is fire a few shots, put on a "handful" of clicks, then fire a few more shots to see which way (and how much) the group has moved.

It's not rocket science.

[conradin]

Surely one of the first things you do with any new gun (after cleaning) is fire a few shots, put on a "handful" of clicks, then fire a few more shots to see which way (and how much) the group has moved.

It's not rocket science.

I know, but there is something wrong with the gun right now, concerning the up/down click. The knob Up/down is so tight I cannot move it without spending a lot of effort. The left right knob is fine and I have it more or less dialed in. At this point I do not know whether the up/down is running out of clicks, or defective.
Long story short, I want to make sure the knobs are turn the right way and be confirmed by others...the gun has been getting more and more inaccurate, despite heaving cleaning. My grouping maintains at around a ring of 7 or 8, but I now have a hard time making it land in the middle. It gets worse and worse. I think a bench test will be needed soon. CCI was very good, then Winchester, also very good, and then everything goes downhill with this batch of SK, and the magazine starts to jam...

Notice the original target group from the user manual is a grouping of 7.(50 ft). I wonder if that is expected from a Izh biathlon gun...the biathlon target is a hit and miss, so people are not shooting for 9s and 10s. My old anschutz 54's original test group is a 9 (50 ft), almost bullet holes on top of another bullet holes..

[Tim S]

If you mean groups within the 7 ring on the ISSF 50m rifle target, that is not good.

If the receiver design allows it, try a different rearsight if you have one.

Also, have you checked that the bedding bolts that hold the barrel into the stock are sufficiently tight?

How are you cleaning the bore?

Your Anschutz test group would have been fired at 50m not 50ft, and I suspect that your 7-4 was too. 50ft shooting is a US peculiarity. At 50ft, a test group from a vice (how Anschutz and many other factories do) should have almost no dispersion at all; a 0.70in test group at 50ft would be awful, but OK (if not brilliant) at 50m.

[crasher]

counter clockwise
left and down

clockwise
right and up

so the top clockwise (up) and the side counter clockwise (move to the left)

So this is exactly the opposite of Anschutz or most German target rifles? (Turn towards Links means you want the shot to go right, turn towards Rechts means you want the shot to go left!)

Yes.

Translated from German, sights on the Anschutz mean shooting to the right, left, top or bottom. So you would move in the opposite direction that it says.

[crasher]

Surely one of the first things you do with any new gun (after cleaning) is fire a few shots, put on a "handful" of clicks, then fire a few more shots to see which way (and how much) the group has moved.

It's not rocket science.

I know, but there is something wrong with the gun right now, concerning the up/down click. The knob Up/down is so tight I cannot move it without spending a lot of effort. The left right knob is fine and I have it more or less dialed in. At this point I do not know whether the up/down is running out of clicks, or defective.
Long story short, I want to make sure the knobs are turn the right way and be confirmed by others...the gun has been getting more and more inaccurate, despite heaving cleaning. My grouping maintains at around a ring of 7 or 8, but I now have a hard time making it land in the middle. It gets worse and worse. I think a bench test will be needed soon. CCI was very good, then Winchester, also very good, and then everything goes downhill with this batch of SK, and the magazine starts to jam...

Notice the original target group from the user manual is a grouping of 7.(50 ft). I wonder if that is expected from a Izh biathlon gun...the biathlon target is a hit and miss, so people are not shooting for 9s and 10s. My old anschutz 54's original test group is a 9 (50 ft), almost bullet holes on top of another bullet holes..

I think that you are having issues with the rifle and not the sights. At 50 feet, you should be able to put it through the same hole. So check the action screws or make sure the sights are loose. Also have you tried other magazines or have you cleaned the magazines if they are jamming?

[conradin]

If you mean groups within the 7 ring on the ISSF 50m rifle target, that is not good.

If the receiver design allows it, try a different rearsight if you have one.

Also, have you checked that the bedding bolts that hold the barrel into the stock are sufficiently tight?

How are you cleaning the bore?

Your Anschutz test group would have been fired at 50m not 50ft, and I suspect that your 7-4 was too. 50ft shooting is a US peculiarity. At 50ft, a test group from a vice (how Anschutz and many other factories do) should have almost no dispersion at all; a 0.70in test group at 50ft would be awful, but OK (if not brilliant) at 50m.

The Izh has a grouping tested at 50m, and if you apply that test paper on a 50 feet target paper, then it is a grouping of 7. (of course if you apply that to the 50m target, it will probably be somewhere between a 9 and a 10). The old Anschutz free rifle I used to have was bullet hole thru bullet hole, with the grouping being, the radius of a bullet hole.
I'm wondering if this is what I should expected from the Izh as far as accuracy is concerned. Should I expect something is similar when I bench test it, and if it is worse, what does that mean?

[Tim S]

It doesn't work like that.

The groups you get at one distance will not be the same as the groups you get at longer or shorter distances. Accuracy is sort of angular (maybe more bell shaped than a cone), but groups get bigger at longer distances. Of course a 50m group will look awful on a 50ft target; 50m is over three times further away, so the group will be at least 3x larger than at 50ft. A .70in 50m group should translate to a much smaller 50ft group.

I do a lot of my shooting at 25 yards (a British peculiarity), so I know from experience that a good group is a little over calibre sized. I think the last group shot from a test rig at 25 yards was within a 7mm circle (that's ten shots). So at 50ft, I would expect even smaller groups.

If your rifle is has started to shoot significantly larger groups than normal, something is wrong. An obvious cause would be that the sights or bedding bolts are loose, and are moving under the recoil. Why not check that these are tight? If the barrel is normally free-floated , check that it still is.

You said that accuracy was good with CCI and Winchester ammo, well try those again. Perhaps the SK was faulty; it may simply not suit the rifle 's barrel, although 7-ring groups are a bit extreme at 50ft.

[conradin]

I finally, with help, fixed the diopter problem, and have now marked the setting.