Combat Rifle Zero
BY Herschel Smith
4 years, 11 months ago
John Lovell has an interesting video up on AR-15 zero.
If you want more, and a somewhat different approach, Shawn Ryan has a video up of his 36 yard zero and why he does it that way.
On January 8, 2020 at 10:01 pm, 15Fixer said:
Thank you for posting this!! I read a couple years ago about the 36-yard ZERO, and have been using it ever since. Nice to have a resource to let others know, and try……
On January 10, 2020 at 8:59 pm, George said:
Travis Haley had a really good youtube video on the various zeros and took them out to 500. He got crossways with the source company and it is no longer available. I had hoped he would re-do it. He used those semi-realistic dummy head and torso targets and showed the impacts at all the distances from 25 out to 500.
On January 10, 2020 at 9:00 pm, George said:
Because of that video I switched to a 300 yard zero. It works great.
On January 19, 2020 at 10:24 pm, Georgiaboy61 said:
The standard carry handle sights on an AR15-pattern rifle are designed to be zeroed for a near-zero of 25m and a far-zero of 275m, for use as a battle-sight zero from 0-300 meters. Originally, M193 55-grain FMJ/Ball @ 3240 fps from a 20-inch barrel, and then M855/SS109 62-grain FMJ/Ball “green-tip” @ 3020 fps, beginning with the NATO adoption of that cartridge as standard in 1980. From 300 meters out to the maximum effective range (either 600 or 800 meters, depending on the design of the carry handle sight), elevation adjustments are made using the elevation wheel. All of these parameters were designed into the original 20-inch barrel rifle; the carbine length barrels came later.
The Army still teaches the 25m zero for iron-sighted M16s and M4 carbines, whereas the Marine Corps has adopted the 36-yard zero zero as its battle-sight zero. The Army has transitioned completely to meters, whereas the Corps still uses yards, the reader will note.
Many Marines now learn the Santose Improved Battlesight Zero – which is a method of zeroing the carry-handle sight to a 50-yard/200 meter zero, or its follow-up, the Revised Improved BSZ, which allows the carry-handle to be zeroed at 25, 50, 100 and 200 yards while still retaining the 300-600 meter capability of the carry handle. Both systems are easy to learn, but often will require a taller-than-stock front sight blade, which can be ordered easily.
The 36-yard zero is very flat-shooting out to 275 yards, where the elevation wheel can take over at 300 meters or longer shots.
Optics – whether red-dots such as Aimpoint PROs, reflex optics like the Eotech, or fixed power low-power optics like the ACOG – can offer considerable freedom for choosing a zero, or conversely have design requirements stipulating a specific type/range for zeroing. ACOGs, which the Marines call the RCO – “rifle combat optic” – are designed for zeroing at 100 meters or 100 yards, depending on the specific model being used. Trijicon uses versions graduated in both units.
Obviously, equipment, the type of shooting being done and the range expected, play a large part in how the rifle/carbine is zeroed. Also whether operations are to be in daylight, or during the hours of darkness.