Air Arms Owners Club

maybe a silly question, do you prefer to use HIGH or MEDIUM mount's on an air arms s410 walnut thumbhole with a 50mm objective scope, at the moment i have sportsmatch MEDIUM mounts fitted & the gap between the barrel & the scope objective is about 6mm,the scope i'm using is a MTC OPTICS mamba pro 2 5-30x50i,reading the scopes manual it sets the following.....

ideally, your scope should be zeroed to your rifle as near to it's adjustments range as possible, on some rifles, to achieve this it is necessary to SHIM the lower cradle of the REAR or FRONT mount using a thin sliver of silver foil.this can be folded for extra adjustment,BUT SHOULD NOT EXCEED 0.3mm thickness to avoid damaging the scope,i used 6 strips of negitave film to get near close to achieving this, it was still a tad out !!! i have been looking online to get medium adjustable mounts & they are only available in HIGH,i'm looking at sportsmatch uk 2 piece double screw adjustable high 30mm HIGH 30mm mounts,in your opinion will these suit my need's, what's the down side to taller mount's rather than medium.

i use the adjustable mounts on my photon work find .
you can get one piece high adjustable i believe .
worth a look on ebay as well .

one piece will not work on the s410 due to the 10 shot magazine.

The downside of the taller mounts is you loose your cheek contact unless you have an adjustable cheek piece,. If the cheek piece is adjustable you van vary the height to alter near and far zeros, which increase with increasing scope height.

If you want to shim more than 0.3 mm make some tapered shims. All you need is aluminium foil. Cut an isosceles triangle with a 15 degree angle, height 6x the width (front to back) of the ring, Z-fold from apex to base to create 6 layers.... it will be single thickness at the edges and 6 thicknesses in the middle. Carefully lay it in the lower half of the ring with the apex underneath pointing towards the other ring.

What you have done is re-profile the curve in the ring - reducing the depth in the middle without reducing the width - and creating a slope, front to back. The slope needs to be in the right direction, with the apex pointing to the lower ring. You change the thickness of the shim by using thinner/thicker foil.

If shimming by more than 0.5mm make shims for both rings, a thin one and a thick one, so as well as changing the height you are also putting a front-to-back slope in each ring,

Shims are a bodge - it's always better to use adjustable mounts - but can give you a quick fix.

I'd just go with whatever is more comfortable...