Researching 7.62 AR 10 Style 16" Carbine Battle Zero

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3GunEric

3GunEric

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When you search around online there are tons of blurbs about how old uncle Joe held his M14 in SE Asia. I really cannot find any scholarly articles that discusses options and pros and cons for selecting a 7.62 iron sight battle zero. (Already have DD5V1 w/ 16" barrel so don't need to hear about how you think my barrel is too short - that's my own personal matter!

I did this not too long ago and came up with many good options (and articles/discussions) for my 5.56 20" HBAR.

What about the 7.62? Really interested in info on iron sights but have 4x QD ACOG on there.

Thanks for your consideration.
 
250 Meter "Battle Zero" was used with the iron sights on the M14. 250 was also used as the starting Zero for the M14 with a ART Scope. (AKA Leatherwood ) I would suggest that you comb a few Military Manuals for 16 inch 7.62 x 51mm firearms. Perhaps even the SCAR. JMHO.
 
Seems like if you know your sight height, bullet weight and ballistic coefficient, and muzzle velocity, all you need to decide is how far above line of sight you're willing to have maximum arc trajectory.

Throw all that into a ballistic calculator, such as http://www.jbmballistics.com, and you'll get a point blank zero for that given maximum arc height above line of sight, and a maximum point blank range.

That's how I'd do it anyway.
 
WrongHanded said:
Seems like if you know your sight height, bullet weight and ballistic coefficient, and muzzle velocity, all you need to decide is how far above line of sight you're willing to have maximum arc trajectory.

Throw all that into a ballistic calculator, such as http://www.jbmballistics.com, and you'll get a point blank zero for that given maximum arc height above line of sight, and a maximum point blank range.

That's how I'd do it anyway.
Click to expand...

Exactly. No 16" 308's were issued for battle (maybe a para FAL? Maybe?), so a battle sight zero just doesn't exist. With your preferred load, shoot it over a chronograph, plot the rise/fall, and determine your acceptable rise/fall. that will give you your maximum point blank range, which is the technical term for "Battle sight zero".
 
I think part of the answer to this question lies with the ACOG reticle and how it is to be set up or how you intend to use that reticle. I know nothing of those.
I have always set my 16" and 18" 308's to zero at 250-265 yds.
I dont think there is anything wrong setting up a 300yd. zero, just know you will be aiming a little low to hit at 150. And also that after 300 it begins to drop quickly.
 
Using a 25 yard zero gives a 250 yard zero with Oron sights on M-14 .I zero my M1 A to 200 yards with my low as possible scope on it. I checked and with ball ammo a 50 yard zero is pretty close to get that.
 
Shooting approxamately a zillon .308 rifles with milsurp ammo at targets out to 400 yards, a solid 50 yard zero will be better than most folks can see from 0-250 yards.

Don't over think it!

Most ballistics calculators will print a "point blank zero" if you do want to over think it and have a place to set targets at the recommended distance :) But simply a 50 yard zero with all but the exotic calibers will be close enough for government work :)

Unless you are regularly winning local F-class matches, you'll set a much more accurate zero at 50 yards than a 200-300.
 
50 yard zero's are only accurate at 50 yards, using a 50 yard zero at 200-300 yards is the least accurate 200 & 300 yard Zero you shall ever utilize. JMHO. But there is a bit of experience behind this. Want a 300,600,900,1200 yard zero? Shoot it and annotate it in your log book. Just My Not So Humble Experience.
 
M118LR said:
50 yard zero's are only accurate at 50 yards, using a 50 yard zero at 200-300 yards is the least accurate 200 & 300 yard Zero you shall ever utilize. JMHO. But there is a bit of experience behind this. Want a 300,600,900,1200 yard zero? Shoot it and annotate it in your log book. Just My Not So Humble Experience.
Click to expand...

Depends on the target. A fifty yard zero with my SCAR 17 is only 1" low at 200 yards and 10" low at 300 yards. That's plenty close enough to kill anything I want to kill without adjusting my point of aim from 50-300 yards.
 
I shouldn't be surprised that a topic as simple as picking a zero for a common rifle shooting a common round equipped with a common sight could lead to wrangling and nit-picking.

Anyway, I've deleted some posts to try to reset the thread back to a more productive exchange.
 
In addition to the SCAR-H/S, there are SR25 variants with shorter barrels (we called them SR25K), as well as for the HK417 (which I never used), and 16" Larue OBR's have one many a sniper comp.The purpose of the shorter barrels is the advantage in reduction of weight and length, especially when using a suppressor. This pays dividends when moving through confined spaces or doing activities like climbing, fast roping, parachuting, and pretty much anything besides using the rifle on a static range firing line. We normally zeroed our irons at 200 meters. They were only there for emergency use of the rifle in the event the scope was damaged in the field. Are you shooting in the tactical iron division? Does your ACOG have a 7.62 reticle? Also, I wish PSA made a AR10 variant with a medium weight 16" barrel.
 
I think the best option is to try to maximize the point blank range, you should try to figure out what bullet you will mostly shoot and what velocity.

Then, use jbm software to determine what the max point blank can be

Then, compare that to the real work performance of the acog sighted in according to the acog Instructions

You should be able to dig up the reticle details in your acog as well, after you figure out how you want to sight in the gun, take notes and go valid the reticle at the ranges the software predicts
 
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FL-NC said:
In addition to the SCAR-H/S, there are SR25 variants with shorter barrels (we called them SR25K), as well as for the HK417 (which I never used), and 16" Larue OBR's have one many a sniper comp.The purpose of the shorter barrels is the advantage in reduction of weight and length, especially when using a suppressor. This pays dividends when moving through confined spaces or doing activities like climbing, fast roping, parachuting, and pretty much anything besides using the rifle on a static range firing line. We normally zeroed our irons at 200 meters. They were only there for emergency use of the rifle in the event the scope was damaged in the field. Are you shooting in the tactical iron division? Does your ACOG have a 7.62 reticle? Also, I wish PSA made a AR10 variant with a medium weight 16" barrel.
Click to expand...

My first steps into the "AR 10 type" platform. (Yes I know it has to be Armalite to be an AR10)

I have been doing 3 G for years. Have Colt Competition (Now out of business) w/ 1x6 on it. Actually been using my older Colt HBAR w/ irons more over the last year. Did juice it up w/ MI free float fore end, Magpul UBR stock and Timney trigger. It is the best of the old and new.

Had a chance to get the DD5V1 for $1400 and traded a gun I got for free for the ACOG w/ Larue Q/D mount. Does have the 5.56 reticle though. I have my 5.56 HBAR all sighted in 50/200 yards zero - and it is dead on. 0-200 yards = center of mass, 300 yards = head, 400 = aim at top of his "top hat." Bingo Looking for similar recipe for 7.62.

Before this deal popped up out of the blue I was seriously looking at PSA!
 
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