My new CZ550, 416Rigby, Warne, Helia combo shoots 8" low when the adjustment on the Helia is in the maximum bottom position. The mounting should be OK I first tried Millet (before they broke) and it had the same problem then. I got some advice that it might be something wrong with the rifle, perhaps the barrel is bent or perhaps the treads on the barrel or in the action are badly done.

Has anybody heard something about this on some other rifle or has any idea about it?

I shoot a 5 shoot group meassuring about 2" but it was 8" low with no possibility to adjust any further.

I allso got the advice to try turn the scope 90 degree to see if the same error returns after sighting in again. To eliminate the scope.

I shoot 400grain Hornady SP at about 2350 fps.

I'm about to get a new barrel (450Rigby) but if ther's something wrong with the rifle I probably should try to get a new on warranty claim first.

I badly need advice.

Many thanks.

By the way, I got the dies from CH4D a few weeks ago and I should probably get the reamer from JGS this week. Its only the new barrel thas missing (and perhaps a working rifle...) before the smith can take over.

Thomas,
Try the iron sights, and see how it does. Then, at 50, turn the scope 90... and see...

Will be interesting to hear the outcome.
jeffe

Thomas,

I am probably being real dumb here, but humour me. Try adjusting the vertical adjustment on the scope in the opposite direction and see what happens to the point of impact....

Pete

Pete E

If I turn the adjustmen the opposit direction the bullet hits the ground half way to the target...

The adjustment knob goes up, the reticle goes down to the point where nothing happens anymore regardless of how much i turn it. This is when I hit 8" low. If I turn the opposit direction the reticle obviusly goes up until the bullet won't find the target att all anymore hitting below.

If I'm wrong dont be shy telling me, I will never stop learning new stuff.

I'm on a busines tripp 'till christmas but will try the ironsights first thing next year. I will report my findings here.

Thomas M,
Have you looked down the bore, as in bore sighting, and compared where the bore is "looking" to where the scope and iron sights are looking? A bent barrel would be obvious just by looking down the bore.

There is less likely something wrong with the gun than with the rings, or the scope.

The CZ 550's come with a test target from the factory. Three shots at 100 meters. Of all the CZ 550's I own, the groups are 3/4" to 1.5" on paper. It might be done from a machine rest at the factory, and I don't know if they use a scope or the irons, at the factory, so their testing might not preclude a botched receiver integral base, front or rear.

I suspect there is something wrong with the rings or scope. It would be hard to get a rifle through the QA that had a cockeyed or bent barrel. That would affect stock bedding unless it was just out at the muzzle end of the barrel. The integral bases on the receiver could be boogered, or your rings or scope.

You are right about the Millet CZ rings being trash. They are not even fit for 22 rimfire.

Hi Thomas...
I just experienced the same....
I just tried to adjust my CZ550 375H&H to 100 meters, I managed to do it but with my vertical adjustment at the "end of travel".
for info:
I used 300 grains Hornady RN SP, 70 grains V150. velocity 2500ft/sec
I received all kind of suggestions, from re-arranging the scope as suggested here in this forum, but also suggestions as removing 1mm or so from the front base or scope mount.
I am using warne mounts.
I am very interested to hear more, I am considering changing mounts.
Any ideas gentlemen!!!

Hi again Thomas..
Just some "ad on"
I use a Leupold vari-x II 3-9.
I did the bore sight.

Your 450 rigby project sounds interesting!!

Thomas and voyager,
I have never had such a problem with six different CZ's, using CZ, Warne, and BRNO rings.

For this problem:

Q: With the scope at the midpoint of its adjustments, where does it point relative to the bore when boresighting?

A: Too high. The scope looks up and the barrel looks down.

Q: Why?

A: Either the front ring or base is too high, or the rear ring or base is too low, or the scope is defective.

Q: How do we tell?

A: Measure the ring heights from base to center line of scope, and measure the base heights from center line of bore to top of base, looking for the discrepancy. If there is nothing significant, then back to scope boogered, assuming the iron sights and the barrel bore sight properly and give proper elevation when fired at paper.

Q: Have you guys tried your iron sights, the factory express sights, with standard loads? I always do that first at 25 or 50 yards, then move on to scope.

A: ???

Hi Daggaron

Thanks for your advice, but I am sorry, it did not help me.
Here is what I did:
1 Iron sights check OK with my "own" ammo.
2 Adjusted the scope to both ends of travel, then to neutral and x-checked with the bore sight - OK
3 Then used the scope and adjusted it, but I ended up exactly as before...

Any other idea...Maybe a new set of mounts.

Daggaron,

What will happen if they use a straightedge on either the bottom of the rings, or the top of the mounts? Will placing the straightedge (and/or scope ring lapping tool?) on the "high" ring or mount, flush all the way from front to back, not show a clearance at the "low" ring?

Are the rings identical in dimension?

With new rifles I am inclined to treat this as a warranty problem, but if that is not possible, and "slope" turns out to be the problem, a taller mount (they come in sizes!) and/or shimming up the low (rear?) mount (longer screws and shims available from Brownells and perhaps others)is a good solution. Another would be the eccentric ring inserts with Burris rings. I like those.

It wouldn't be too hard to "squish" a scope with axially parallel rings at different heights. I'd take a good look at the outside of my scope and, if the shop sold me the rifle and the mounts and the rings and the scope and mounted the scope, consider whether or not the shop owes me a new scope.

Are CZ 550s supposed to be free-floated? Barrel mashed into front of fore-end?

Daggaron is way too good to need any help at this, but I was interested in what looking for slope would show, so I thought I'd contribute a little.

Oops, didn't know they had integral bases...

Since your Iron sights are fine, your problem most likely lies in either the mounts or the scope. A bent barrel or cocked receiver threads is most likely not the cause. To check the mounts, first Lap Them( Brownells sells a great kit for this with both 1 inch and 30MM lapping bars). Dont try doing this with sandpaper as the purpose is to grind a straight hole in the rings. I've found that many Warne scope mounts are asymetrical and need to be Lapped. This helps in two ways. First you eliminate high spots that could cock the scope and second you have a firmer surface to avoid the scope moving under recoil. Once you've done this, find a 3 ft long 1 inch or 30 mm steel bar ( borrow or buy one) and mount it in your rings. Eyeball it and assure that it's parallel with the barrel. If so, it's not the mounts. If not, you have a front or rear mount thats height is incorrect. Make sure that when you installed the Warne rings that the rings fit flush with the CZ bases and that you can't see any light under the base to ring fit. It's easy to cock a set of rings with a improperly fitted dovetail.
If the rod is not parallel, remove the rings and lay it on the action bases. Look again for parrallel. If the bases are not parallel. then all you can do is mill them down till they are. I doubt this is your problem. My bet is it's your rings.
If everything is parallel, then it's your scope. Try it on another gun and confirm.
Hope this helps.-Rob

Talley now has rings for the cz550.

Some bizarre stuff, here: voyager can line up the bore and the iron sights to work, but the scope will boresight onto target and not work? That is some strange scope! Maybe it has smoke and mirrors built into it?

Oh well, Rob has some good advice, but SDS's idea with the the straightedge across the ring lower halves would be a lot easier quick check.

In summary: Beats me.

It sounds like your scope tube is bent.

Take it off the gun, and place the scope on top of a miter box (or anything with two parallel sides that will allow the scope turret to rotate unimpeded) so the tube on either side of the turret is supported.

Roll the scope back and forth; it the tube is bent, one end of the scope or the other will show an eccentric orbit.

If the tube is bent, and the scope is worth it, you might want to send it back to Kahles for repair. Otherwise, dump it, and get a new scope.

Hope this helps,
George

[ 12-02-2002, 20:53: Message edited by: GeorgeS ]

I got the factory 3 shoot group and it seems ok. The Helia scope has aluminium body and got some ugly markings from the Millet mounts...

My guess is the factory group was done with the iron sights, if the barrel isn't in a straight line with the action the iron sighs would shoot "straight" but with a scope you (I) have a problem.

If I look through the bore everything looks ok but if I then look through the scope, I look up in the sky...

The stock had mucho tension when the action and barrel screws were tight. If I loosened the barrel screw, the barrel would suddenly become freefloating. I bedded the front lug and the barrel lug but did nothing to the rear action screw.

Could it be that the not bedded screw could bend the entire action so the rear scope ring is lower than the front ring? I will try to loosen it to see what happens.

I must check the scope to see if it's still round or bent.

Thanks a lot for all advice, I will test everything until I find the cause of this mess.

Thanks again!

George S,
Good thought.

If the junk Millet rings let go at the front ring and recoil momentum bent the front of the scope upward by bending the tube at the top of the arc of muzzle rise, then this might explain it ... ???