MOA help
- Thread starter cherocapri
- Start date
The #1 community for Gun Owners of the Northeast
Member Benefits:
No ad networks! Discuss all aspects of firearm ownership Discuss anti-gun legislation Buy, sell, and trade in the classified section Chat with Local gun shops, ranges, trainers & other businesses Discover free outdoor shooting areas View up to date on firearm-related events Share photos & video with other members ...and so much more!
Member Benefits:
kalister1
R.I.P.
Basic load data says it shoots flat out too 200 yards.
Attachments
Major03
Ultimate Member
Depends...but the ballistics are different than the .223/5.56.
It probably makes sense to get the velocity and ballistic coefficient for your round and use a ballistics calculator (there are several good ones online for free).
I concur for .223 the 50/200 is a great zero. I went with a 25 yd zero for my 300 blk
YMMV depending on if you’re shooting subsonic or supersonic and what weight bullet / powder combo.
- Feb 4, 2013
- 28,175
Easy to zero, and no math/calculator needed.
And can be done with less than 5 rounds.
Bore sight optic to bore.
Fire one round at 25 yard target. If you are happy that you did not pull it, continue.
Put rifle in rest of sandbags so that the optic is centered on the target (where you were aiming). Without moving the rifle, adjust the scope so that the optic is centered on the bullet hole. If you want to be fancy, for .223 with a 55 grain bullet, adjust the optic to be about 3/4 inch above the bullet hole.
Fire one round at 100 yard target, repeat above adjustment.
Done
3 round groups can be used, but if you are confident in your shooting ability, they do not add anything, especially at the 25 yard range
- Feb 4, 2013
- 28,175
And yes, an actual MOA is 1.047" at 100 yards. But many optics are set up for Shooter's MOA, which is 1.000" at 100 yards.
So either look up the specs for your optic, or test.
Or don't worry, as the difference is less than 1/2" at 1000 yards.
So either look up the specs for your optic, or test.
Or don't worry, as the difference is less than 1/2" at 1000 yards.
Major03
Ultimate Member
Yes, that’s a great process in general to attain a zero, but what about the choice of what range to set his zero?
For all practical purposes, most shooters benefit from a zero where, give or take a few inches up or down, point of aim is point of impact.
Hence the 50/200 zero for a .223 recommendation. Point of aim should be good out to about 250 yds or so.
A 300 BO has a much less flat trajectory, and that’s where I think the ballistics calculator comes in handy. Not only in aiding the choice of what range to set your zero, but also in understanding what limitations it places on you.
I only have access to a 25 yard and 50 yard range. I'm going to zero my sight based on some 300blk 124 grain hornady SST rounds. I guess figuring out the flattest zero based on the ranges of 1-50 with a ballistic calculator would be best. I like to zero with my potential HD or hunting ammo, I do not often have time to go to the range.
Sent from my SM-G930P using Tapatalk
tkd4life
Ultimate Member
And yes, an actual MOA is 1.047" at 100 yards. But many optics are set up for Shooter's MOA, which is 1.000" at 100 yards.
So either look up the specs for your optic, or test.
Or don't worry, as the difference is less than 1/2" at 1000 yards.
This. What does 0.047 inches look like? It’s negligible. And 0.5 inches at 1000 yds isn’t going to be observed with the best shooters with the best rifle. Anyone who could shoot 0.047 inch groups at 100 yds consistently would be a record breaking shooter and rifle combo.
Biggfoot44
Ultimate Member
- Aug 2, 2009
- 33,199
The choice of zero distance is a * Choice * . Different perspectives and philosophies. My take for my version of relative context emphasizes limiting the amount of spacing of poi being Above the poa at short to medium distances , even at expense of needing more apparent hold over at longer ranges. Other preferences, in other contexts will sacrifice defacto dead on aiming at medium-ish distances for absolute maximum distance to get hit somewhere on man sized target .
Greatly oversimplified rule of thumb- 1.5in high at ( certian distance ) .
For more or less modern high vel ctgs , 100yd .
For lower vel ctgs , 50yds ( also includes shotgun slugs , PCC, etc ).
I know seems oversimplified, but actually works pretty well. Main "weakness" is short changing the capabilies of really flat shooting ctgs .
Greatly oversimplified rule of thumb- 1.5in high at ( certian distance ) .
For more or less modern high vel ctgs , 100yd .
For lower vel ctgs , 50yds ( also includes shotgun slugs , PCC, etc ).
I know seems oversimplified, but actually works pretty well. Main "weakness" is short changing the capabilies of really flat shooting ctgs .
- Jul 29, 2014
- 50,026
Absolutely. It all hinges on what the weapon is to be used for ie, shooting deer anywhere between 20-250+ yds or slapping steel at 600 yds, etc. Everyone has their own ideas and ideals.
Biggfoot44
Ultimate Member
- Aug 2, 2009
- 33,199
Or if you are a .mil , for average grunt to score a hit anywhere from forehead to ankle, while aimed at belt level , out to farthest distance vs hit somthing size of soda can to 200-ish yds , and have to think about holdover at long distances.
For civillian hunting , recreational shooting , home defense , and LE Patrol Rifle , the latter much more useful . For .mil , no first hand knowledge, and knowledgeable people whose opinions I otherwise give weight to , have a variety of opinions .
For civillian hunting , recreational shooting , home defense , and LE Patrol Rifle , the latter much more useful . For .mil , no first hand knowledge, and knowledgeable people whose opinions I otherwise give weight to , have a variety of opinions .
- Feb 4, 2013
- 28,175
For most shooters, Maximum Point Blank Range is what should be used, unless always shooting at a known single distance.
MPBR means that from the muzzle to some range, the bullet will always strike within +/- some number of inches from the point of aim.
For deer, the suggestion is +/-5 inches, or a 10 inch range. That should put any center of lethal area hold still in the lethal area. The same would work for bipedal targets.
For 5.56, 55 grain FMJ, at 3200 fps, you are looking at sighting in to hit 3.8 inches high at 100 yards, and a MPBR of about 340 yards.
At 25 yards, adjust to hit 0.2 inches high, or 1.6 inches high at 50 yards.
Biggfoot44
Ultimate Member
- Aug 2, 2009
- 33,199
ANNND , I have opposite view to impressive sounding MPBR .
Most shots will still be taken at typical distances . Extreme MPBR will have you hitting 3-5 inches high where you typically shoot. This will require significant offset in your aim , or else can result in a fringe hit , or even a miss .
I think POI should be close to POA out to distances usually fired . When shooting at long distances you will generally have a moment to think about hold over, while short to (average deer distances ) are more likely to be quick, and you instinctively place crosshairs on vital area / desired POI .
To my thinking , I want plus 1.5 or most 2.0 high , and 5 , maybe 6 inch low . Hold where you want to hit out to zero distance, and beyond until drop 1.5in or so . For drops up to 5-6in holding on spine/ top of back will still give center chest hits .
Most shots will still be taken at typical distances . Extreme MPBR will have you hitting 3-5 inches high where you typically shoot. This will require significant offset in your aim , or else can result in a fringe hit , or even a miss .
I think POI should be close to POA out to distances usually fired . When shooting at long distances you will generally have a moment to think about hold over, while short to (average deer distances ) are more likely to be quick, and you instinctively place crosshairs on vital area / desired POI .
To my thinking , I want plus 1.5 or most 2.0 high , and 5 , maybe 6 inch low . Hold where you want to hit out to zero distance, and beyond until drop 1.5in or so . For drops up to 5-6in holding on spine/ top of back will still give center chest hits .
Major03
Ultimate Member
Biggfoot44, respectfully, I disagree. The whole point to MPBR is that you DON'T have to offset your aim and that POI and POA are within a set distance of your POA within distances of "what you would reasonably shoot). The idea being that +/- 3-5 inches will get you meat in the freezer provided you don't exceed ranges where the bullet drops below your acceptable variance from POA...and THEN you have to start offsetting. Or are you saying that 3-5 inches is beyond your comfort zone in terms of what's "close enough?"
Pinecone...I think we're actually in agreement. I think of 50/200 zero as a "typical" MPBR for a 55 gr .223 bullet, and where the POA = POA within a couple of inches. Your suggestion just ups the acceptable variance in POA/POI a few inches more in order to gain more yardage in range. Nothing wrong with that at all. In both cases, the goal of that zero is to minimize the consideration of bullet drop by the shooter and to be able to quickly place rounds onto target that will have "effect" out to a certain range before the shooter needs to start offsetting or adjusting his turrets. Perhaps semantics, and the 50/200 zero isn't really a MAXIMUM point blank range...but the concept is the same. Point, shoot, and expect the bullet to hit "close enough for business" to where you aimed within a set yardage. What constitutes "close enough" can be determined by the shooter's comfort level and goals.
How does one know what to set their zero at for a given bullet and velocity, within what that shooter wants to have as their acceptable trade off for variance in POA/POI and range? I know I'm preaching to choir for most here, but that's where the ballistic calculator comes in. Jump online and just plug in the bullet weight, the bullet's ballistic coefficient and velocity and you can experiment with different zero's and where that would put the round at what yardage vis a vie bullet drop. Confirm on the range. This is also an invaluable tool if you are shooting different bullet weights, especially if they vary a lot like switching up from super sonic 300 BLK to subsonic 300 BLK.
Pinecone...I think we're actually in agreement. I think of 50/200 zero as a "typical" MPBR for a 55 gr .223 bullet, and where the POA = POA within a couple of inches. Your suggestion just ups the acceptable variance in POA/POI a few inches more in order to gain more yardage in range. Nothing wrong with that at all. In both cases, the goal of that zero is to minimize the consideration of bullet drop by the shooter and to be able to quickly place rounds onto target that will have "effect" out to a certain range before the shooter needs to start offsetting or adjusting his turrets. Perhaps semantics, and the 50/200 zero isn't really a MAXIMUM point blank range...but the concept is the same. Point, shoot, and expect the bullet to hit "close enough for business" to where you aimed within a set yardage. What constitutes "close enough" can be determined by the shooter's comfort level and goals.
How does one know what to set their zero at for a given bullet and velocity, within what that shooter wants to have as their acceptable trade off for variance in POA/POI and range? I know I'm preaching to choir for most here, but that's where the ballistic calculator comes in. Jump online and just plug in the bullet weight, the bullet's ballistic coefficient and velocity and you can experiment with different zero's and where that would put the round at what yardage vis a vie bullet drop. Confirm on the range. This is also an invaluable tool if you are shooting different bullet weights, especially if they vary a lot like switching up from super sonic 300 BLK to subsonic 300 BLK.
- Jul 29, 2014
- 50,026
Baby steps, Lol.
You can get as deep as you want in this stuff. It all depends on the individual and their needs. It's not for everybody, but there are plenty of sites on line that can teach you as much as you want to know and practice.
Me, I'm a deer shooter, not a bench shooter, so I try to keep things pretty simple.
Major03
Ultimate Member
Sorry about that...it’s a shooting forum and I tend to geek out.
It’s not that complicated really. If you think about it, because your eye isn’t looking directly down the barrel and is above it, the rifle is canted upwards at a tiny angle to meet your line of site. Your zero is where they intersect.
Bullets will be shot upwards ever so slightly because of that angle and then immediatley start being effected by gravity. The result is a parabolic curve.
Because the rifle is angled upwards to the line of site a smidge and it’s a curve, it will cross the line of site twice. This confuses people sometimes when they hit higher than what they did closer in, even though they’re thinking they shot further away so the bullet should be dropping more.
Since different bullets weigh different amounts and different powders push them at different speeds...that curve is a little different for each bullet. Some are flatter like a .223 and some are downright rainbow shaped like a 300 BLK subsonic.
The choice of zero is just a choice of how to take advantage of that curve to meet your needs. A ballistic calculator just gives you a very close estimate of that curve so you can figure it all out.
Clear as mud right?!
Blacksmith101
Grumpy Old Man
- Jun 22, 2012
- 22,283
It is a shame that many shooters don't have a basic understanding of Ballistics in general and most don't know the ballistics of the rounds they shoot.
If you want a better understanding of either I would recommend the following as a start:
The father of modern ballistics was F.W. Mann and he wrote a book "The Bullet's Flight From powder To Target" which is available on line;
https://babel.hathitrust.org/cgi/pt?id=uc1.b4522233;view=1up;seq=10
For coverage of available cartridge ballistics data there is "Ammo & Ballistics 6";
https://www.amazon.com/Ammo-Ballist...coding=UTF8&psc=1&refRID=CG2YJ38202FM667R5ZPF
If you want a better understanding of either I would recommend the following as a start:
The father of modern ballistics was F.W. Mann and he wrote a book "The Bullet's Flight From powder To Target" which is available on line;
https://babel.hathitrust.org/cgi/pt?id=uc1.b4522233;view=1up;seq=10
For coverage of available cartridge ballistics data there is "Ammo & Ballistics 6";
https://www.amazon.com/Ammo-Ballist...coding=UTF8&psc=1&refRID=CG2YJ38202FM667R5ZPF
Users who are viewing this thread
Latest posts
-
-
-
-
Montgomery County Gun Buyback: Interfaith GVP Network Aims to Hit $30,000 Goal by April 20 (5 Viewers)- Latest: TruthAloft
Forum statistics
Latest threads
-
-
Sign up on our online store and earn 1000 points- Started by J_Gunslinger
- Replies: 2
-
-
-
-
-