Hi all,
I just got a wild hair to write up a range report on my experience using the USMC 25m zeroing procedure to dial in my AR-15. If anyone’s interested it can be found here:
http://sites.google.com/site/jimmyhots/usmc25mar-15zero
All constructive comments, suggestions, critiques are welcome.
Jimmy
This is a good concise review especially for thos who are un familiar with it. I do have to correct one thing though. This is not the USMC 25m zeroing procedure. It is in fact the U.S. Military (Army, Navy, Airforce, Marine, and Cost Guard) 25m zero. It is the standard zero procedure for all issued M16 / M4 rifles and cabines. Some services may do thing differently due to missions optics etc but for the most part this is it.
Thanks, Jimmy. I’m always on the lookout for new things to read, whether it’s something I know, or a new perspective.
Ziptie
Great write up, thanks.
I realize that this is being anal…but I’ll throw this out for S/A
With the A1 and 193 ammo we BZO’d on 25 yards, when we were issued the A2 and eventually the 855 rounds made it to us, we started doing BZO from 25 meters. It’s a difference of a little over 7 feet, it could be a factor at the 300 meter and beyond ranges.
Yes this is a little confusing to me, because I’ve heard this referred to as the USMC zeroing procedure, yet the manual is US Army. Wasn’t sure if perhaps it originated with USMC and is used by Army, or vice-versa…?
JH
looks good jimmy,
did you happen to count how many clicks from the condition where the front sight’s notched disk is flush with the front sight base’s top surface.
that is a good thing to know in case you ever have to remove the post for some reason.
very nice write up
Is that target for zeroing the M16A2 twenty inch barrel? Looks like your rifle is a sixteen inch M4 civilian rifle.
Will be interesting to see how your long range shooting comes out.
Please keep us informed.
Thanks
Semper Fidelis,
Tipy
Thanks for your input- I updated the article with an addendum that addresses this.
Also thanks to Tipy for pointing out that I was using an A2 target with a 16 inch rifle; I made some updates to address the M4 vs A2 zeroing targets and how using the A2 target with a 16 inch rifle affected my zeroing procedure.
Can’t wait for further results.
Semper Fidelis,
Tipy
Super article, very well put together.
For my department, however, we advocate the 50/200 yard zero, which has smaller differential between point of aim/point of impact between point blank and 200 yards. This is in addition to the fact that it is highly unlikely any officer would engage a threat any farther than 200 yards, especially in built-up areas.
Dead on. The 25m procedure is an Army-authored procedure meant to be universal to all branches to establish a 300m BZO with iron sights, and even then, only as one method for that type of zero. It’s a standard, not the standard.
The Marine standard is a 36yd (33m) procedure that is known as a “Field-Expedient Zero” procedure. It is not meant to replace known-distance zeroing procedure in the same fashion that the Army method is (or is not, depending upon whom you speak to; I’ve heard it both ways from folks at Picatinny and other entities). In the article, the OP states: “…why the USMC zeroing procedure does not sight at first cross-over is beyond me.” I submit that we already do so, and have for several decades.
See MCRP 3-01A, [i]Rifle Marksmanship[/i], specifically Chapter 9 “Zeroing.” That’s a current publication, signed as valid by LtGen BB Knutson Jr of MCCDC 29 Mar 2001, with updates done since then. That pub supersedes the rifle-specific portions of FMFM 0-8, Basic Marksmanship and all of FMFM 0-9, Field Firing for the M16A2 Rifle, of which my copy shows being signed as valid by LtGen CC Krulak of MCCDC 26 Dec 1992.
Jimmy, you’ve already noticed the existence of a…I’ll be kind and call it a discrepancy…in using Army publications to assert what is or is not USMC doctrinal or training policy. This is a case of wishful thinking on the part of the Army just because we’re forced to buy stuff off of contracts that they are the primary contract-holder for; that’s the publishing equivalent of lying about your sexual escapades to your buddies. Sounds great and builds up your ego in front of your pals, but it’s still bullshit. Certainly not your bad, but that of the publishers.
While it’s not uncommon for some individual Marine units to use the 25m method because the targets are easy to get from multiple sources (the one you used is distinctly identifiable as Army, since those published by the Corps say 36yd on them and do not have the little pictures of the windage/elevation adjusters on the targets), 25m for rifles is not the USMC standard. There’s not a school-house or marksmanship training entity within the Corps that teaches it. Even if they did, it would be with the caveat that it is a field-expedient method ONLY, with KD confirmation being a requirement and not a helpful suggestion.
Riverine-
Nail, head.
Army-published TMs for the stuff we buy are among the many banes of my current existence, is all. I have to fight that 25m jive a lot. Like the OP said, the procedure doesn’t ballistically match the platform, or at least not closely enough to make real sense for a 300m BZO. Add to that the fact that the Corps is historically a fairly xenophobic organization, and the idea that we’d use Army methodology simply because they said so becomes even more ridiculous.
It’s enough to make an otherwise mild-mannered Beta male like myself kick a kitten through a fan.
Besides which, the fact that he’s citing a -10 manual…well, I’m 90% sure that it’s been superseded by a newer Army pub. I’ll have to check on that once I get to the office.
Riverine,
Try 3-22.9
Thanks for the reminder. That’s the one that the boss had when I checked on it today…and promptly forgot about it. Oops.
He had the hardcopy, only. Here’s an open source for the PDF: http://www.robert-morris.edu/SentryHTML/pdf/rotc_fm3_22.9.pdf
I think the 50 yard zero is a more appropriate system for most applications.
+1
For me, the whole point of starting 25yds is just to make sure that I’m going to be on the paper at 50 or 100yds, and to make any obvious windage adjustments (not elevation).
After 5 rounds at 25yds I usually straight to 50yds, and after a couple more 5 round groups and some fine tuning there, it’s off to 100yds, and from there to 200yds.
I haven’t shot at 300yds yet, but I’m planning to do so this weekend… There’s no sense speculating about trajectories when you can just shoot and see where the bullets strike!
Bimmer
Thanks I see a lot of good stuff in this doc, but I’m having trouble downloading the entire pdf. Know of any other sources?
JH
Woah your 25 yard zero curve looks to have a second crossover way downrange, past the 300-350 yard mark. I get your point that the 200 yard zero has a smaller deviation at close ranges but your 25 yard zero has second crossover occurring at such a long range that the deviation is really high. A 300 meter/328 yard zero should have a max deviation of about 6 1/2 inches, not 9+ inches.
I’m curious- what software are you using to plot your graphs?
JH