I'm blowed if I know why.............

[fizzbangwhallop]

I bought a CZ17HMR a few years ago and in July 2009 I upgraded the 'scope from a 30mm Swaro 3-9x42 to a 1" Swaro AV6-18x50 with the fine BR reticle(1/4" clicks) - ideal for long shots. Couldn't get enough low elevation adjustment with a standard pair of Sportsmatch mounts and a visit to the factory sorted me out with an OP15C mount with the .75mm vertical taper. Excellent, chuffed with that and the 3-9x42 went on the .22

 

Last year I traded my trusty Ruger 10/22 Target for a Sako Finnfire with a 'skinny' barrel and fitted the 3-9x42 - no problems. When the money allowed, I went for the same 'scope/mount combination as the .17 - the 'scope, bought from Macleods, is just 2 serial nos. removed from the original.

 

Could I get the .22 zeroed at 25metres? Elevation adjustment at it's maximum but on the Point of Aim, but with the windage at it's maximum I was still 1.25" to the right of POA! Merde! Back to the 3-9x42.

 

Thinking it was down to a wider dovetail I didn't get very far asking if Sportsmatch could mill a bit off the dovetail rail to centralise it and then found the Burris Signature rings with the offset 'optilock' style insets kit - took months to arrive and then were much too high for my liking, back to the 3-9x42.

 

Still bugging me over the winter, so the other week I tried the 'scope/mount from the .17 - it zeroed with plenty of adjustment left?!

 

Huh? Thinking I'd made a pigs ear last year I went back to scratch yesterday and re-fitted the new 'scope and mount to the .22, double checking my levels as I went. Same result, not enough adjustment on the turrets, windage still 1.25" out.

 

So, now both 'scopes and mounts apart, refitted the .17 combo to the .22 and vice versa from scratch. There's a slight difference in the 2 dovetails between the CZ and the Sako meaning the fishplates are reversed between the 2.

 

And today, both rifles are zeroed happily but I'm blowed if I know why....................

 

Any ideas gratefully received.

 

All the best,

 

Fizz

ps Set of Burris Signature rimfire rings and the extra offset rings kit going

[6.5shooter]

Would the scope mounts have been put back on the gun in the opposite direction to the previous time? Ie: instead of the screws for tightening youre mounts to the scope rail on the rifle being on the bolt side of the rifle theyre now on to non bolt side. Port to starbord or starbord to port?

Just an idea?

 

Garry

[fizzbangwhallop]

Hi Garry,

 

I know where you're coming from........ the mounts are inclined and should be fitted with the bolts on the left, if they had been the round way round I'd have never got the elevation close. The 'reversing the rings' trick works fine with different sizes of dovetail if the rings of your mounts are the same height and I've always used bolts on the right up to this point on various 1" & 30mm 'scopes on my old Titan MPT pre-charged, on the Ruger 10/22 and on the .22's & the .17. Same with anybody-elses rings I've ever fitted.

 

I mentioned this 'reversibility' when I spoke to Sportsmatch about the problem last summer and he agreed that most mounts he'd fitted generally ended up with the bolts on the right, didn't offer a solution to my problem though.

 

One thing I didn't mention earlier was that when going back and starting again with the .22, I ran the Swaro from limit to limit on the turrets to find the mid-points only to go too far one-way (if that's possible) on the windage and find it stuck fast - so off to Swarovski to be unjammed. (Doh! Read the instructions!). Came back last week.

 

So I know the 'scope is fine, must be something to do with the second Sportsmatch mount and the slightly different dovetail profiles between the CZ and the Sako. Perhaps Sportsmatch changed the specs or the machine tools needed changing or had a batch manufactured third-party - they've always been good in the past .

 

Who knows?

 

Cheers

 

Fiz