Geometric puzzlement

[Barry]

Thanks Baldie, a very informative and helpful response. Being new to this I sat scratching my head for hours, then someone at the club said 'put some packing under the rear scope mount', which I guess, for what I do and what I do it with, is good enough.

But, the method doesnt appeal to my sense of the way things 'should be' or your 'ideal world' scenario.

I should imagine, that packing the rear scope mount will misalign the fit of the tube through the front mount by tilting the scope by a tad, and that doent fit with my ideal either.

Are adjustable scope mounts available for a HW100 with a scope with 30mm tube?

Again, Many thanks

Barry

[sarf]

But, the method doesnt appeal to my sense of the way things 'should be' or your 'ideal world' scenario.

I should imagine, that packing the rear scope mount will misalign the fit of the tube through the front mount by tilting the scope by a tad, and that doent fit with my ideal either.

I fully support you Barry, stick to your principles and do it right! If you want to be even more fussy, insist on one piece mounts, and lap the tube to the mounts to avoid any misaligment strain on the tube.

Tedious but satisfying.

P.S. on a lot of (especially German) scopes from years back there was only elevation adjustment, no windage adjustment; the elevation turret had no cover as you were expected to adjust it in the field rather than doing "hold over/hold under". There was no windage turret because you were expected to have adjusted/aligned the mounts in the first place.

[sarf]

Are adjustable scope mounts available for a HW100 with a scope with 30mm tube?

http://www.sportsmatch-uk.com/atp61.htm -

ATP61 - New Adjustable Elevation and Extra High Two piece 30mm Mount. Saves having to pack the rear mount. Point of impact can be adjusted on the mount. The height is between 1.5 and 2.8mm higher than our standard 30mm high range.
Please note both front and rear mounts tilt to maintain correct alignment.
Air Rifle / .22 Rimfire Rifle 30 mm High range for 9.5 mm - 11.5 mm dovetails up to 60 mm Lens Dia.

(I have the one inch Sportsmatch adjustable which is one piece).

[Barry]

Sarf......What is 'lap the tube to the mounts'?

[sarf]

- using very fine abrasive to ensure that the inside of the mounts are perfectly round and exactly the same diameter as the tube (they certainly won't be on mounts that cost £30 - £50).

You can using fine grinding paste on a length of 30mm steel bar (ideally), or you can stick a bit of e.g. 1000 grit wet-and-dry to your scope and rotate that in the mounts (see http://www.bloom.co.uk/images/sportsmatch_honing-s.jpg)

Warning (1): the latter method will inevitably tend to over-bore the mounts due to the thickness of the paper, so proceed with great caution. The "lapping bar" method is superior - if you can find a piece of perfectly round 30mm bar . . .

Warning (2): doing any of this is regarded as eccentric/daft by most airgun owners