same plane? what does this mean?

[lonewolf21]

im about to order a larue buis, the advertise that you can get it with a same-plane apature. what does this mean.

[28_days]

That means that both apertures (short and long distance) will be zeroed at the same time. The way I understand it is that if you zero the short distance aperture, the long distance aperture will be zeroed at that same distance as well.

Can anyone explain further? Is it worth $25 to save a few minutes of convenience, or am I missing something?

[Failure2Stop]

Same plane is in vogue right now.

With the standard A2 sights when the small aperture is zeroed at 300 yards/meters flipping up the 0-2 sight will provide an approximate 200 yard/meter zero. This permits the small aperture to be used in conjunction with the elevation drum to provide effective fire at longer ranges and the 0-2 to be used for close range and low-light. Remember though that the sight system was designed before widespread use of more technologically advanced sighting devices such as RDSs. Also bear in mind that there is no guarantee that the 0-2 will actually provide a correct zero at 200, though in my experience it does just fine at 50 and closer. This is due to two issues- (1) manufacturing irregularities and (2) user perception. (2) seems to be the biggest issue as the larger aperture makes clinical sight alignment difficult, a necessary fault to enable the user to rapidly establish sight picture and more light transmission in low-light situations.

We have come a long way since the A2 was introduced, not only in optic technology but in application as well. Since most gunfights are happening within 300 meters the elevation drum is becoming more and more irrelevant (as is the easily adjusted deflection knob), and since the most pressurized fights are happening at under 50 meters, the 200/50 yard/meter zero and 100 yard/meter zero are proving to be the most effective zeroes when they really matter. As such, having a sighting system that does not require the user to differentiate between POA/POI at close range depending on aperture used can be beneficial.

I personally prefer the standard A2 sighting arrangement for a fixed BUIS with a weapon that is caipable or expected to be employed at distances up to or past 300 meters. A gun that is not expected to be employed past 200 meters (dedicated CQB guns) generally benefit from a same-plane setup.

Just my £ 0.01