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3/20/2017 5:03:23 PM
Posted: 5/29/2002 3:22:18 PM EDT
I've heard that the Marines are now using a 36 yard zero procedure. I'm not sure what the trajectory cross over is but I thought it was less than 36 yards.

Does anyone know how this new method compares to the 25 meter or the 50 yard zero?

I did a search here and couldn't find much information other than it being mentioned.
Link Posted: 5/29/2002 4:20:21 PM EDT
For at least the last decade plus we have BZO at 36m's with M16A2s. 5.56mm isn't full stabile for the first 27m's of flight.
Link Posted: 5/29/2002 6:30:39 PM EDT
Well then I guess it's just new to me

Got any more info on the benefits of a 36m BZO?
Link Posted: 5/29/2002 6:35:54 PM EDT
STLRN, according to the BST Book 2 PVT-LCPL ICB, on page 2-11-33, it states that zeroing the M16A2 is done at 25 meters.
I remember doing the 25 meter zero in bootcamp in '91 and also at MCT.
At Cherry Point, we used to do our zero on the pistol line.
But IIRC, when I qualed last fall, we zeroed at 36 meters, but I don't remember for sure. (not starting an arguement, but I remember doing most of my zeroing at 25 meters)

Muad, the reason for the short zero is to get you in the general area. After you do your short zero, you "need" to fine tune it at 300 meters.
Link Posted: 5/29/2002 6:55:46 PM EDT
I understand the concept behind the 25m zero, which is what I use now. I'm interested in the benefits of the 36yard zero over the 25m though. I hadn't heard that 5.56 isn't fully stable until 27m until now, or at least I don't remember hearing that before. It makes sense.

What is the upper deviation from point of aim within 300m using a 36m BZO?
Link Posted: 5/29/2002 6:57:21 PM EDT
Look in your rifle data book (NAVMC 42) it goes through the 36 meter zero method (which should be done at all rifle ranges). At Lejeune the BZO range at Stone Bay is 36 m. If we BZO on main side and cannot get to the range we can use the 25m pistol range to BZO and use the hasty 25 m method (not recommended because the previous mentioned instability of the projectile for 27ms). The recent test by 3/2 recommended we go to the 25 m BZO vice the 36 meter BZO because of ease of finding 25m vice 36 meter ranges
Link Posted: 5/29/2002 7:07:03 PM EDT
http://hometown.aol.com/dsgriffn/Bookletad2.html
Check out the above site. I'm not affiliated with this guy, but I heard about it and checked out the link. Apparrently, if you zero the A2 at 36yds, the weapon is also zeroed for 300yds also. Without pulling out my manual, if you zero at 25m, the rifle is also zeroed for just over 300m, maybe 325M? In fact, the bullet crosses the line of sight twice if the sights are set correctly, once going up and once coming back down. If zeroed at 36yds, the point of aim and the point of bullet impact coincide at 36yds and 300yds. The point of bullet impact will be above your point of aim between these 2 points. Thoroughlly confused? Maybe not. You could adjust your sights in such a way in which the bullet never crosses the line of sight but this would have no practical use. Hope this helps.

jd1
Link Posted: 5/29/2002 7:24:45 PM EDT
[Last Edit: 5/29/2002 7:26:05 PM EDT by Corey]
Muad:

Didn't you go with the 50/200 BZO?

To me, that makes the most sense with a carbine. There's only about 2" deviation from you point of aim all the way from 50-200 yards, and then it only drops a bit more so it's probably good out to 250.

If I understand it correctly, a 50/200 BZO will still allow you to use the dial on your A2 sights to punch in a 300, 400, etc. zero. I haven't confirmed this at range, of course, but am relying on the information (which has always proven to be reliable) at communities.msn.com/TheMarylandAR15ShootersSite/zeroingmethods.msnw.

I have ballistic printouts on the comparision of these BZO's. The 50/200 looks like it makes a lot more sense for realistic ranges, plus allows you to dial in longer zeroes.

Good to hear from you again bud. Let's get together here in the near future to burn some and I'll bring my BZO file.

PS I think I've got the bump nailed! What a way to piss off the locals, but damn it's fun!
Link Posted: 5/29/2002 7:41:43 PM EDT

Originally Posted By Corey:
Muad:

Didn't you go with the 50/200 BZO?

To me, that makes the most sense with a carbine. There's only about 2" deviation from you point of aim all the way from 50-200 yards, and then it only drops a bit more so it's probably good out to 250.

If I understand it correctly, a 50/200 BZO will still allow you to use the dial on your A2 sights to punch in a 300, 400, etc. zero. I haven't confirmed this at range, of course, but am relying on the information (which has always proven to be reliable) at communities.msn.com/TheMarylandAR15ShootersSite/zeroingmethods.msnw.

I have ballistic printouts on the comparision of these BZO's. The 50/200 looks like it makes a lot more sense for realistic ranges, plus allows you to dial in longer zeroes.

Good to hear from you again bud. Let's get together here in the near future to burn some and I'll bring my BZO file.

PS I think I've got the bump nailed! What a way to piss off the locals, but damn it's fun!



Good to hear from you! Schools out for the semester, summer classes don't start until the 17th. We should try to get together sometime soon.

I just started "practicing" the bump last weekend. I didn't do it much but managed to get three or four rounds off at a time. Completely unaimed of course, but it still made both my wife and I grin from ear to ear.

I was going to change to the 50yd but never got around to it. I haven't had any problems with a 25m BZO but I don't ever get the chance to shoot past 100 yards. And of course it shoots high at that range.

I guess I need to go to a long distance range and check the deviation differences between the two BZO methods.
Link Posted: 5/29/2002 7:54:21 PM EDT
[Last Edit: 5/29/2002 7:56:39 PM EDT by Corey]
Muad:

Email me with some of the times you're free over the next week or so.

I'm starting to have fun with the pistola again. Got some great new practice targets I made. Pretty challenging, even from 5 yards. (EDIT: Read "small.")

I'm all ammo'ed up and itching to share in some of this BRC weekend festivities, even though I'm hundreds of miles away.

Shoot me a mail and I'll get back to you tomorrow. I'm out for tonight.

EDIT noted in text.
Link Posted: 5/30/2002 10:06:36 PM EDT

Originally Posted By Muad_Dib:
I've heard that the Marines are now using a 36 yard zero procedure. I'm not sure what the trajectory cross over is but I thought it was less than 36 yards.

Does anyone know how this new method compares to the 25 meter or the 50 yard zero?

I did a search here and couldn't find much information other than it being mentioned.




Figure it out yourself


www.norma.cc/htm_files/javapagee.htm
Link Posted: 5/31/2002 4:32:31 AM EDT

Originally Posted By SIX:

Originally Posted By Muad_Dib:
I've heard that the Marines are now using a 36 yard zero procedure. I'm not sure what the trajectory cross over is but I thought it was less than 36 yards.

Does anyone know how this new method compares to the 25 meter or the 50 yard zero?

I did a search here and couldn't find much information other than it being mentioned.




Figure it out yourself


www.norma.cc/htm_files/javapagee.htm



Very cool! Thanks for the link!
Link Posted: 5/31/2002 6:38:52 AM EDT
36M zero has 2 advantages:

1) You don't need to reset your dial - just keep it so it bottoms out at '3'

2) It works (i.e. gives a true 300M trajectory - unlike the 25M 8/3+1 zero).

That being said I prefer the Santose IBZ (50y/200m). The flat trajectory is nice when doing precision shooting and I can always click up to the 300M setting...
Link Posted: 5/31/2002 1:31:12 PM EDT
I second the Santose method. You may still need to adjust a click at 300, but the flat trajectory and improved sight pic at shorter ranges by the smaller aperture is not to be ignored. How often do we actually engage targets beyond 200 meters?
Link Posted: 5/31/2002 6:24:16 PM EDT
Muad:

If you were hitting the center of the target the last time that we were shooting you have a 50/200 BZO. You may not have the correct negative dial to make the numbers work, but....

For everyone's information, if you want to forget about dialing between the small and large apertures, get the $28 Ashley same plane rear aperture. Yeah, it's a bit bigger than the A2 but I got use to it. Now there's no dialing between large and small aperture and when I click up using the dials (theoretically) the numbers read true.

Best and simplest solution to the complex problem of BZO's. If I want a 300 BZO, I turn the dial to 300, and same for 400 on up. But if I bottom it out on the negative clicks, then I'm back to the tried and true (standard) 50/200 BZO. No ajdustment between apertures. Everything is simple and reads true.

I like it!!

'Course, at some point I need to get my arsh out to a longer range (I'm limited to 100 yards at my club) to see how this "theory" works out....
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