The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

I am looking at buying a 30mm extended scope rail some thing like a spur I know nothing about scopes when and why would you fit a 20 minute of angle rail over a normal flat rail whats the advantage if any.
Its going on a Ruger precision we have some young guys in the Club who are trying to promote long distance outings I thought I might give it a go. (Perhaps ? may be.)

it gives you an extra 20moa of adjustment of elevation.

With a 0moa your elevation on your scope will be roughly in the middle of the total available. by adding the extra 20 your scope zero will be lower down allowing for the extra elevation adjustment, allowing for longer ranges to be shot by just winding the scope.


Alan

Pretty sure Ruger Precision Rifles come with 20MOA rail built in - best to check

Yes when I get my next rig, probably a Tikka T3X, I will get a 20moa scope mount for it. Just for the long range shooting that I might do.

Probably never use the extra 20moa but the rings that I get (tier one), they will come with no extra cost.

I have a 8.9 mils (30MOA) on my AI and use the lot at 1200 yards and around 75MOA on my little rimfire tube rifle and have used most of that as well.

Ovenpaa wrote:I have a 8.9 mils (30MOA) on my AI and use the lot at 1200 yards and around 75MOA on my little rimfire tube rifle and have used most of that as well.

Didnt understand any of that. I think I need to have a conversation with some of the new younger guys in the Club that shoot long distances.

I just checked the Ruger precision comes fitted with a 20 minute of angle rail as standard so that sort of answers my own question. So I guess I just need a flat jobby.

Normal rails are flat and parallel so that the scope axis follows the bore axis (more or less). The 20moa rail is sloped such that the rear of the rail is taller than the front which points the scope downwards slightly.

Why do this? With a flat rail the zero for your scope is about halfway through the elevation range. If a scope has a total elevation of 60moa and you zero it when the glass is at the middle of the range, that leaves 30moa of adjustment left over. Depending on calibre and distance you desire to shoot, 30moa may not be enough adjustment, so the act of using a 20moa rail is to move your zero further from centre (eg in our example 30moa - 20moa = 10moa) which gives you 50moa elevation for total elevation adjustment.

Perhaps we are asking the wrong questions/making the wrong comments. Alpha1 - why do you want to get a different rail?

I have an RPR in 6.5CM. The built-in 20MOA rail is fine to get me to 1000 yards using a scope with 70MOA of built-in elevation, but there isn't enough elevation to get past 1300 yards. If it was in 308, then I'd be lucky to get to 1200 yards.

So you need to establish:
How far do your members want to shoot.
How much built-in elevation has the scope got
Whether the reticle of the scope include alternative aiming points to 'add' elevation.

Triffid