Zastava mount , ring , scope problem

A young mate has bought one of the wooden stocked 223 Zastava's and a vx1 to go on it. nice wee gun
The problem is he cannot get enough "down" on the scope to zero it, it's 4-5 inches high at 25 yrds
The Mounts cannot be reversed as the screwhole gaps are different
He was given what look like weaver, or weaver type mounts and cheap rings
The back mount is higher than the front, but there is still plenty of bolt handle/scope clearance.
I swapped the rings out today for a pair of my low Leupy prw's but that still left us 2-3" high at 25yrds.
Anybody else had this trouble or any easy fix,I could shim the back one up but would prefer a clean fix cheers

He cannot just take it back and ask them to sort it as he has had it for a year or more with a red dot scope and that was able to be zeroed

Coke can shims would be the easy fix, otherwise take some material off the bottom of the front weaver block, then use epoxy to ''bed'' it back onto the action, the epoxy will fill any ''roughness'' and make sure it’s all aligned sweet. Then lap the rings to get them aligned correctly so you don't kink the scope tube.

Sounds hard, but it’s a 20 minute job (plus curing time of glue).

kj

Thanks Kimjon, never actually though about taking metal off the bottom of the front mount, easy done.
cheers

Or use Burris Sig-Z rings.

brris rings are fantastic for fixing this type of problem
greg

Cheers Chaps.

Ah that would be shim front or lower rear mount wouldn't it !

Sent from my GT-S5360T using Tapatalk 2

If I shimmed the front, or put a higher front, or lower rear mount, wouldn't that raise the poi even more.
Not too sure , which is why I posted
cheers.

Imagine the scope is in a vice on target. The barrel is pointing up cos its shooting high .
To point the barrel down would need the front mount higher or the rear mount lower right;)

Sent from my GT-S5360T using Tapatalk 2

Think iron sights for a minute
The old 303 rear sight goes up a ramp for more range. Raise rear sight = raise poi
Same for rings raise rear or lower front =shoot higher

Sent from my GT-S5360T using Tapatalk 2

Yep, VC is spot on, to drop poi you need to raise the front mount or lower the rear.

Oh! Yes you're correct VC.
It’s been so long since I've had to do it I'd obviously forgotten which way around it was. I used to do a lot of air-rifle hunting and you could never get the scopes to the correct POI on an air-rifle with its rainbow trajectory so shimming was always a necessity...but that was 10 years ago when I was in the UK so my memory had failed me, thanks for correcting the mistake.

kj

Alright, we are onto something here, Thanks Cam , spud, kj..

So do you reckon if i put a lower ring mount on the back with the standard size on the front, that this would lower the point of impact .
But would it twist/bend the scope body unacceptably

That would be a massive change wouldnt it? Id try shimming first.

Ok I'll try that first. so shim the front mount up shoot and see
As I said above I've tried swapping for lower decent rings and now we can actually hit an A4 sized peice of paper but still 3" high at 25.
I've never struck this problem before where I can't get a scope sighted at 25yrds, it weird.

You can work out how many MOA you'll need by using some simple maths.

1) Wind the elevation turret from one extreme to the other and count the MOA adjustment available i.e. if it turns 30MOA from hard stop up, to hard stop down, then ideally you'd want it at 15MOA (or whatever half of your adjustment range is?) when zeroed.

2) You're 3'' high at 25m, so that’s about 12MOA.

3) So you need 12MOA + 15MOA (or half your adjustment range whatever that is???) = 27MOA of shimming or about 6.75'' (171mm) of height on your target


Next Stage:

4) Measure the gap between the rings (say 150mm?????)

5) Use a ratio equation to work out the rough thickness of the shim required:

a=total drop required
b=distance to target

ratio = a/b

ratio = 0.171m / 25m = 0.00684

Now use this ratio, but apply it to the gap between the rings (instead of the gap to the target) and you'll know the difference in height required between the two rings i.e.:

ratio x gap between rings = shim thickness

0.00684 x 150mm = 1.026mm (thickness of shim required)


Just replace the numbers above with the values you've measured (gap between your rings and your scopes total MOA adjustment) and you can then work out the thickness of the shim required like I've shown.

kj

Thanks.Appreciate that.

See if they're the right number bases, don't shim stuff, it'll fuck the scope