Scope Mounts Height/Dimensions is my maths correct??

[oldskoolzzz]

Ok it's been a long day and I'm trying to work out something does this sound right?

1) Take 25mm scope mounts let's say they are 17mm height from base to bottom of the cup.

If I take the 17mm and add half the scope diameter 12.5mm for a 25mm scope this gives me a centre line of 29.5mm

Say the scope has an external objective size of 53mm if I half that it gives me 26.5mm

Therefore the 29.5mm centreline with those mounts would give me a 3mm clearance for the objective as the barrel is flush with the bottom of scope rail does that sound correct?

Assuming I'm correct this is the example I need to get correct

2) Take 30mm scope mounts this time, let's say they are also 17mm height from base to bottom of the cup.

If I take the 17mm and add half the scope diameter 15mm for a 30mm scope this gives me a centre line of 32mm

Say the scope this time has a bigger objective of 56mm if I half that it gives me 28mm

Therefore the 32mm centreline with those mounts would give me a 4mm clearance even with the bigger objective size?

Does this sound correct or have I ballsed up and got it totally wrong

[bighit]

any good ?

http://www.mil-rad.com/scope_ring_calculator

[angrybear]

Ok it's been a long day and I'm trying to work out something does this sound right?

1) Take 25mm scope mounts let's say they are 17mm height from base to bottom of the cup.

If I take the 17mm and add half the scope diameter 12.5mm for a 25mm scope this gives me a centre line of 29.5mm

Say the scope has an external objective size of 53mm if I half that it gives me 26.5mm

Therefore the 29.5mm centreline with those mounts would give me a 3mm clearance for the objective as the barrel is flush with the bottom of scope rail does that sound correct?

Assuming I'm correct this is the example I need to get correct

2) Take 30mm scope mounts this time, let's say they are also 17mm height from base to bottom of the cup.

If I take the 17mm and add half the scope diameter 15mm for a 30mm scope this gives me a centre line of 32mm

Say the scope this time has a bigger objective of 56mm if I half that it gives me 28mm

Therefore the 32mm centreline with those mounts would give me a 4mm clearance even with the bigger objective size?

Does this sound correct or have I ballsed up and got it totally wrong

Yes, the objectives are only 3mm different half of which is high so the objective clearance is 1.5mm less, but the thicker tube has raised the centre line by 2.5mm so in effect the objective clearance has increased by 1mm.

You could also say 56-30=26, 26/2=13, 17-13=4 so 4mm clearance.

[oldskoolzzz]

Yes, the objectives are only 3mm different half of which is high so the objective clearance is 1.5mm less, but the thicker tube has raised the centre line by 2.5mm so in effect the objective clearance has increased by 1mm.

You could also say 56-30=26, 26/2=13, 17-13=4 so 4mm clearance.

Brill

Thanks for the comfirmation

[oldskoolzzz]

any good ?

http://www.mil-rad.com/scope_ring_calculator

Thanks for the link bud but I couldn't get that program to run properly for some reason

[bighit]

Thanks for the link bud but I couldn't get that program to run properly for some reason

not tried it my self.