Professional Soldiers ® - View Single Post - M-4 50m zero vs. 25m zero

Sinister · 12-15-2008, 10:07

Reinforcing Gene's point, the reason this comes up again and again is because folks either don't have real field fire or KD ranges to no-shit confirm their zeroes or they've never done it.

More a point of "Don't know" and "Never done it."

It seems the majority of shooters train and practice between 25 and 100 meters and never seriously shoot at anything past 200 -- ever. There are the occasional trips to the qualification range to shoot pop-ups, where a hit to an E-type (anywhere) drops it -- and the shooter doesn't know if he hit center, a wrist, the top of the shoulder, or base of the scalp.

A GI 25 Meter zero will put most shots in the upper 1/3 of a 300 Meter E-type. Given the dimensions of the head a slight breeze will blow many shots off-target.

A 50-Meter zero will give you more of a centered, center-of-mass grouping at 300. If you think of Center-of-Mass as truly the center of an E-type (minus the head) you reduce the risk of losing any over the tops of the shoulders in any kind of breeze.

20 years ago at Range 37 all students zeroed at 100. This worked for the majority of shots since everything for 6 weeks was closer than that.

Unfortunately Musketry practice in both SOF and the GP Forces now seems to concentrate at much closer than 50 Meters. Farther seems the realm of folklore or "Don't know how to train it" unless it's on the pop-up range.

Thermometer targets like Gene described work for rough zeroes all the way to 1,000 if you know your come-ups. If you don't have proper paper thermometer targets you can improvise by taking an E-type, turning it upside down, and gluing something like a round Shoot-and-See target where the face would be.

Using your elevation drum or the range markings on your irons, Aimpoint, or ACOG you start by placing bullets at Center-of-Mass of the bull for 100. Come up to your 200 and 300 settings and you'll see your groups go up the thermometer stalk. With an ACOG you can go all the way up your markings (I think to 800).

This is the same method the Marines use for confirming sniper scopes on helo deck 25-Meter ranges. At 25 Meters set your scope for 300 and your groups should be 5/8ths-inch high (using an M40A1 and the older Unertl or something like an M3LR).

12-15-2008, 10:07	#28
Sinister Quiet Professional Join Date: Jan 2004 Posts: 261	Short Range Zeroes Reinforcing Gene's point, the reason this comes up again and again is because folks either don't have real field fire or KD ranges to no-shit confirm their zeroes or they've never done it. More a point of "Don't know" and "Never done it." It seems the majority of shooters train and practice between 25 and 100 meters and never seriously shoot at anything past 200 -- ever. There are the occasional trips to the qualification range to shoot pop-ups, where a hit to an E-type (anywhere) drops it -- and the shooter doesn't know if he hit center, a wrist, the top of the shoulder, or base of the scalp. A GI 25 Meter zero will put most shots in the upper 1/3 of a 300 Meter E-type. Given the dimensions of the head a slight breeze will blow many shots off-target. A 50-Meter zero will give you more of a centered, center-of-mass grouping at 300. If you think of Center-of-Mass as truly the center of an E-type (minus the head) you reduce the risk of losing any over the tops of the shoulders in any kind of breeze. 20 years ago at Range 37 all students zeroed at 100. This worked for the majority of shots since everything for 6 weeks was closer than that. Unfortunately Musketry practice in both SOF and the GP Forces now seems to concentrate at much closer than 50 Meters. Farther seems the realm of folklore or "Don't know how to train it" unless it's on the pop-up range. Thermometer targets like Gene described work for rough zeroes all the way to 1,000 if you know your come-ups. If you don't have proper paper thermometer targets you can improvise by taking an E-type, turning it upside down, and gluing something like a round Shoot-and-See target where the face would be. Using your elevation drum or the range markings on your irons, Aimpoint, or ACOG you start by placing bullets at Center-of-Mass of the bull for 100. Come up to your 200 and 300 settings and you'll see your groups go up the thermometer stalk. With an ACOG you can go all the way up your markings (I think to 800). This is the same method the Marines use for confirming sniper scopes on helo deck 25-Meter ranges. At 25 Meters set your scope for 300 and your groups should be 5/8ths-inch high (using an M40A1 and the older Unertl or something like an M3LR).
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