Some days it's better to stay home....

[armoredman]

I was ready to go try out my new loads for the CZ 527, and hotfooted it down to the range as soon as I could. I set up at 100 yards, and was planning on walking it back to 200 as soon as I checked zero...good thing I did.




What the...this was zeroed last time I checked! Instead of moving it back, I spent the next 40 minutes trying to get this scope to hold to a zero...well, here's the last 4 groups fired.



Case in point, the one on the lower right - the taped group was shot first, then the scope adjusted up...and it went down and to the right.
I have to confess, this is my very first scope, I mounted it myself, (sitting in my lap), and it's a cheapie. The group sizes show the rifle is doing it's part, that first one being 3/4 inch, the others range from 1 and 3/4 to 1 and 1/4, and one baaad one taped up on the upper right...oops.
Is it the scope or is it me?

[armydad]

I had this same problem on a new hunting rifle that came with the scope mounted.  I did not check the mounting screws and low and behold it drifted.  I had to tighten them up to correct the problem.  Maybe this will help.

[jwc007]

I had this same problem on a new hunting rifle that came with the scope mounted.  I did not check the mounting screws and low and behold it drifted.  I had to tighten them up to correct the problem.  

+1 !  I've had mounting problems with a few Rifles.  Rarely was it the Scopes problem.  The only problem I've had with a Scope was on a 3x to 9x Variable, that got stuck on 9x.  Wound up using Iron Sights that Deer Season.  Took two Months to get that Scope back from the Vendors Repair Site and I was only two weeks out from my hunting trip.

[AZ_CZ]

That doesn't look like mounting problems. If the mounts or screws are loose you'll get drifts shot-to-shot with no regular groups like you are showing.  Were you making adjustments between the groups? I had a scope with adjustment settings that bore no relation to their markings; left was right; up Was up, and the amount of recticle movement per click was a guess.

You might also expect some point of aim shift while the barrel heats up, but I don't really see that.  I had a rifle that would group 2 tight then throw one an inch off, cool off then same thing.

[armoredman]

That's what I was doing, trying to zero. I got some good groups, just not near POA.

[jameslovesjammie]

Is your barrel free floated?

Were you shooting off sandbags or a rest?  They all seem to be roughly the same point of impact to me.  If you zeroed your rifle dead on last time you were at the range and they are shooting good groups with a different elevation on the target, I would imagine there is a bedding problem with the rifle. 

My guess would be that last time you sighted in, a different part of the stock was in contact with the front rest and different stress on the barrel.

[jwc007]

Also make sure your Stock Screws are properly tightened.  (Just another thing Murphy came up with to go wrong!)

[armoredman]

No sandbags, no rest, just me, seated, unsupported. Don't have bags or a rest yet.
Barrel is the way it came from the factory, no changes whatsoever.