What does this do?

[sinawalli]

My friend has this Bushnell scope, not sure what model it is. All it has on it is: 3X9X40 AO. It has the windage and elevation adjustments in the usual spot, but it has a adjustable knob on top of the ocular lens. What does this do? This is a pic of what I am refering to!
http://www.bushnell.com/general/riflescopes_banner_71-3959i.cfm

Thanks!

 

[TDC]

The optic has an illuminated reticle. The turret on top of the ocular housing is the rheostat for adjusting the intensity of the illuminated reticle.

TDC

 

[sinawalli]

ok, I know the one in the link has a illuminated reticle, but I don't think this one does! It was daylight, and when I frigged with it, it did nothing with the reticle, that I could tell. Maybe that is what it does! Thanks!

 

[hutchster]

could it be a bdc( bullet drop compensator)?
is it labelled with a caliber or no?

 

[sinawalli]

could it be a bdc( bullet drop compensator)?
is it labelled with a caliber or no?

No, it isn't!

 

[Crazi]

Is it numbered 1-10, 1-11 or similar? Unscrew the top and see if there's a battery in it; replace the battery.

 

[catnthehatt]

It likely lights up the reticle, but maybe the batery was dead?
Cat

 

[Fenix.NZ]

its definately for illuminating the reticle. i have one .
your battery may be dead or else it was never put in

 

[cdngunner]

It tells you its an illuminated reticle right in the ad.

 

[t-star]

your bdc is forward, mounted on the elevation and windage adjustment- i have a couple of bdc bushnells-that's a illuminated reticule- i've also got a range finder one with bdc - the range finder is a couple of stadia wires, and the range is read off a window in the op of the reticlue- it changes as you swap powers