TargetTalk

Hi all,

I know this is a "how long is a piece of string" type question but....has anyone used a Centra Spy rear sight to shoot from 25 yards out as far as 100 yards (or even better 100 metres) ? I'm wondering if it can be done with this sight without having to resort to adjusting the height of the front sight as well. Mostly I shoot 50 metres and that would be my base zero setting for the sight. From there I'm trying to figure out if it has enough up travel to go as far as 100 metres if possible while still have enough down travel for 25 yards. I know 100 metres isn't a standard distance but I have the distance at my range and would like to shoot it for fun. I'd also like to shoot the occasional indoor 25 yard match.

From Centra I've found that they say 1 click moves the point of impact 2mm at a distance of 100m (it doesn't state the sight radius used for this). It has 24 clicks per turn of the elevation knob, so that's 48mm per turn at 100m. Let's say a standard drop of 224mm between 50m and 100m based on Lapua's figures for Center-X, that means 4.66 turns are needed to dial out to 100m - lets call it 5 turns. Let's say 1 turn is needed to go down from 50m to 25 yards at a guess. That means you'd need 6 turns of total elevation and an ideal set-up. Centra don't list the total amount of elevation travel the sight has (how many turns from bottomed out to topped out). Has anyone tried similar with this sight? Anyone know how many turns of elevation travel in total it has if you own one? Sorry about the long winded question and my lack of eloquence in putting it across. Thanks for reading.

I don't, but a number of other British shooters do so successfully; 25yds, 50m, 100yds. Some use Nesom 50/100 foresights, but by no means all. You may need to use a 4mm raiser underneath (or an extra 4mm), so the eyepiece is near the bottom of its travel at 50m.

Thanks Tim. I was considering this sight and wanted to see if it would fit all my means without having the added fiddling about with the front sight. I like the idea of adding forward "cant" by mismatching the front and rear elevation.

Mine measures from .755 to 1.090 on centerline for the aperture from the base (Anschutz). So .335 travel.

I use a centra spy and I have shot it at those distances, as long as the sight is in neutral position at 50m, then you shouldn't have a problem. keep in mind barrel length (and tube length) will determine how much the sight needs to move.

Thank you Andrew for that info. It looks like I should be good to go with a bit of care taken.