I'm doing a KD with a 5.56.
I have a bunch of 55 grain ammo that I normally use at shorter range, but I know it can be badly affected by wind out at 300 and 400 yards.
Would switching to 62 grain offer a Significant improvement vs wind?
Also, what should my initial zero be for the KD event? 25 yards, 50, 100?
Thanks
Between the two, I would shoot whichever is more accurate. Generally, 62 grain will be a little better in wind (depends upon the bullet). I recommend a 25 meter zero.
400 is not that far you could say it is the near edge of far , 55gr works fine if your gun shoots it well. wind , one is lighter but moves faster the other is heavier but moves slower at 400 not a significant enough difference in BC vs Speed for wind to have a significantly greater effect on one over the other. both would still be on target using Fred's simplified wind calculation.
25 meter zero with an AR and most 5.56 ammo 55gr is about 6 inches high at 100 and 300 and 10 inches high at 200 and 3 inches low at 400. so you can run bottom edge hold till stage 4
avoid green tips and bullets that attract a magnet no one likes you beating up their steel with them several ranges prohibit them.
Use whatever your rifle shoots best. With a 1/8 barrel it was no problem to quallify with plain old federal xm193 fmj bulk. Also bare in mind you're not requiring a ten ring group, hits count.
Quote from: Tennessee Beast on May 09, 2019, 01:55:28 PM
Between the two, I would shoot whichever is more accurate. Generally, 62 grain will be a little better in wind (depends upon the bullet). I recommend a 25 meter zero.
At 400 yards, a 62 gr Speer fmjbt at 3100 fps will be deflected 17.01" by a 10 mph 90 degree wind.
At 400 yards, a 55 gr Speer fmjbt at 3300 fps will be deflected 18.27" by a 10 mph 90 degree wind.
So, the difference is minimal (about 1/4 MOA) with regards to wind between 55 and 62 fmj bullets.
If you want a more noticeable difference (1 MOA +) in wind over the 55 gr fmj, you would need to switch to a bullet with a higher ballistic coefficient like the Hornady 75 gr HPBT at 2900 fps (13.82" deflection by a 10 mph 90 degree wind).
Quote from: Badger498 on May 09, 2019, 01:41:33 PM
I'm doing a KD with a 5.56.
I have a bunch of 55 grain ammo that I normally use at shorter range, but I know it can be badly affected by wind out at 300 and 400 yards.
Would switching to 62 grain offer a Significant improvement vs wind?
Also, what should my initial zero be for the KD event? 25 yards, 50, 100?
Thanks
We shot out to 600 at the KD I went to. I went with 55gr Wolf Gold over my Federal XM855 and MX193 because it consistently put together smaller groups off a rest than the other two.
Quote from: Tennessee Beast on May 09, 2019, 01:55:28 PM
Between the two, I would shoot whichever is more accurate. Generally, 62 grain will be a little better in wind (depends upon the bullet). I recommend a 25 meter zero.
:yeahthat:
I have had very little luck with M855. Quality 55g ammo is just fine out to 500 yards. If the wind gets sporty, it's an opportunity to learn shooting in the wind.
Anyone can hold hard on a 4MOA target... reading wind is for tough as nails riflemen. ^-^
I shot 5 for 5 Rifleman KD scores (224,233,237,238,225) with 55 gr FMJ (we shot for score, not hits). Even put 70% in the black when playing around at 600 yards. I suggest a 100 yard zero and then prove to yourself that your rifle does something other than the standard come-ups of 2-2-3-4-5. Mine did not. It is a 20" barrel 1:7 twist Colt; nothing special.
Everything you learned at 25 meters directly applies to KD; steady hold factors, the six steps, NPOA. Wind is not a big issue unless it's really up there and 90 degrees to your bullet path.
Bring home that Long Range rocker!
Thanks for the input guys.
Hearing that a 55g pill can handle this better than I first thought gave me some more confidence in my ammo.
TennesseeBeast, it was a big help to see a quantifiable comparison of the 2 weights and their deflections at distance. This alone made the decision for me, 100% answered my question, and saved me some cash since I didn't need to buy new ammo. :)
TrapperPete, Thanks for the caution about the green tips. It would have been awkward to show up with stuff I wasn't allowed to shoot. :/
Quote from: HammBone on May 10, 2019, 11:14:34 AM
I shot 5 for 5 Rifleman KD scores (224,233,237,238,225) with 55 gr FMJ (we shot for score, not hits). Even put 70% in the black when playing around at 600 yards. I suggest a 100 yard zero and then prove to yourself that your rifle does something other than the standard come-ups of 2-2-3-4-5. Mine did not. It is a 20" barrel 1:7 twist Colt; nothing special.
Everything you learned at 25 meters directly applies to KD; steady hold factors, the six steps, NPOA. Wind is not a big issue unless it's really up there and 90 degrees to your bullet path.
Bring home that Long Range rocker!
Is the 2-2-3-4-5, the increments of elevation minutes between 100, 200, 300, 400, and 500 yards?
Quote from: Badger498 on May 15, 2019, 10:19:40 PM
Is the 2-2-3-4-5, the increments of elevation minutes between 100, 200, 300, 400, and 500 yards?
Those are the comeups for 200-600 with a 100 yard zero, and will keep you within about 1/2 MOA of my drop chart. 20" 1:8 twist shooting Wolf Gold.
Wolf Gold Chart (http://www.shooterscalculator.com/ballistic-trajectory-chart.php?pl=223+Remington&presets=223+Remington%7E223+REM+70gr+Berger+VLD%7EG1%7E0.371%7E70%7E2850%7E100%7E1.5%7E0%7E10%7E90%7Efalse%7E0%7E59%7E29.92%7E50%7Etrue%7E1000%7E25&df=G1&bc=0.25&bw=55&vi=3133&zr=100&sh=2.28&sa=0&ws=0&wa=0&cr=600&ss=25&chartColumns=Range%7Eyd%3BElevation%7Ein%3BElevation%7EMOA%7EFBFFF5%3BWindage%7Ein%3BWindage%7EMOA%7EFBFFF5%3BTime%7Es%3BEnergy%7Eft.lbf%3BVel%5Bx%2By%5D%7Eft%2Fs&lbl=223+REM+wolf+gold&submitst=+Create+Chart+)
Thanks
I shot the KD, and my come-ups also did not match that table on the instruction sheet. Combine that with bad feedback from the target line, and I wasted 3 AQT attempts trying to make corrections. By the time I had it all straightened out, I was fatigued and a 20mph widn was stringing out everyone's groups and blowing hope sideways over the berm.
That was disappointing, since I was keeping 2MOA groups on my best targets, but didn't even come close to qualifying because of the recalculations.
Now that I've shot a KD, I can agree that 55 grain 5.56 is just fine, although the caliber itself may not be the best choice for wind in the first place.
I can also say that I firmly trust Federal's ballistic calculator app more than the instruction sheet. Not only did it give me correct info for my ammo (after the fact), but it let me correctly dial in a .308 bolt gun that was set for 100 yards to get hits at 500 simply by coming up 10 Minutes from zero.
Thanks for the advice on all this and my other posts.
My opinion or zero distance suggestion is 100 yards since that's where we started and it is a practical setup for a rifle.
Sorry to hear you struggled. For future reference, it's my understanding that XM855 (SS109) ammo has a design specification of 4MOA because the inner steel penetrator pin is rarely on the exact centerline of the projectile. When shooting milsurp, I've always had better accuracy with 55 gr XM193.
Thanks ID,
The accuracy of what I was shooting was actually fine, and I'm confident that I could qualify with no improvement in my rifle's performance, or mine. The problem was a miscommunication while developing the comeups on day 1, which set me back and threw otherwise decent groups out of the 5 point area.
I would not go by those generic come-ups if you are shooting .223 Rem or 5.56x45 in an AR. In my experience, they are considerably off the mark. I agree that for the purpose of the Appleseed KD, a 100 yard zero makes the most sense. Then either use hold-overs or dial in elevation corrections for the longer ranges.
The ideal situation would be to sight in your rifle using the ammunition you intend to use at 200. 300, 400 yards, and longer ranges if they will be available for the event. Of course, many may not have access to a range that goes out that far. In that event, I would recommend using a ballistic calculator to estimate the drops you can expect with your rifle and your intended ammunition at the various ranges. See if you can get realistic values for the muzzle velocity and ballistic coefficients for your choice of ammunition, because what is provided by manufacturers and the ballistic calculators is not always accurate. Often the muzzle velocities given are for 20" barrels, and will be lower for the typical 16" barrel carbines. And the ammo makers often give overly optimistic values for the BCs of their ammo. Fortunately, for the more common commercial .223 Rem and 5.56x45 cartridges, someone will have chronoed muzzle velocity from a rifle with the same barrel length as yours, and will have calculated a ballistic coefficient, and these values can typically be found with a cursory Google search.
As for 55 grain versus 62 grain ammunition, if we are talking about 62 grain M855 steel-core green tips, it is true that many people have found them to group a bit less well than 55 grain M193 FMJ, but not everybody. And there are lots of heavier projectiles with a uniform core. Heavier projectiles do have some advantages. Given the same diameter (caliber) a heavier FMJ projectile will have a higher sectional density than a lighter one. Given the same form factor (within reason) that gives the heavier bullet a better (higher) ballistic coefficient. Heavier projectiles have a slightly lower muzzle velocity, but the better BC means they don't slow down as quickly. So at longer ranges, they will have less drop than lighter projectiles. Also, projectiles with a better BC will not be affected as much by wind at longer ranges. If the wind was absolutely uniform, and one could accurately estimate its value, one could compensate for the greater effect of wind upon lighter projectiles. But the fact is wind is never uniform, and nobody estimates its value precisely. So in a significant crosswind, the heavier projectile may have an advantage in accuracy at longer ranges.
Comparing Federal Lake City XM193 55 grain FMJ and Federal Lake City XM855 62 grain FMJ specifically, and using credible values for muzzle velocities from a 16" barrel, and ballistic coefficients, one finds that by 200 yards the velocity of the XM855 projectile has matched that of the XM193 projectile, and far all ranges past 200 yards, the XM855 will be traveling faster and drop less. The XM855 will be a little slower than the XM193 for the first 200 yards, so if you are zeroed at 100 yards, you will have a little more drop at 200 yards, but the difference will be slight and probably not enough to affect your score. By 300 yards the drop of the two cartridges will be virtually the same. Beyond 300 yards, the heavier projectile will have significantly less drop due to its superior BC.
Using a ballistic calculator, assuming a 16" barreled AR carbine and a typical scope mounting height above bore, with a 100 yard zero, the estimated come-ups for XM193 55 grain FMJ are 1.0 MOA from 100 to 200 yards, 2.8 MOA from 200 to 300 yards, 4.4 MOA from 300 to 400 yards, 5.7 MOA for 400 to 500 yards, and 7.5 MOA for 500 to 600 yards (assuming a muzzle velocity of 3150 fps and a BC of 0.243 (G1). So rounding to the nearest whole MOA 1-3-4-6-8, which is a pretty far cry from the "standard" 2-2-3-4-5.
For the Federal XM855 load in the same carbine, again with a 100 yard zero, the estimated come-ups would be 1.1 MOA from 100 to 200 yards, 2.8 MOA from 200 to 300 yards, 4.2 MOA from 300 to 400 yards, 5.3 MOA from 400 to 500 yards, and 6.6 MOA from 500 to 600 yards (assuming a muzzle velocity of 2984 fps and BC of .304). So again with rounding 1-3-4-5-7, a little closer to the so-called standard. Keep in mind an error of 2 MOA at 500 yards is 10" which could be enough to cause you to miss paper altogether.
Quote from: pblanc on May 30, 2019, 11:58:18 AM
Using a ballistic calculator, assuming a 16" barreled AR carbine and a typical scope mounting height above bore, with a 100 yard zero, the estimated come-ups for XM193 55 grain FMJ are 1.0 MOA from 100 to 200 yards, 2.8 MOA from 200 to 300 yards, 4.4 MOA from 300 to 400 yards, 5.7 MOA for 400 to 500 yards, and 7.5 MOA for 500 to 600 yards (assuming a muzzle velocity of 3150 fps and a BC of 0.243 (G1). So rounding to the nearest whole MOA 1-3-4-6-8, which is a pretty far cry from the "standard" 2-2-3-4-5.
For the Federal XM855 load in the same carbine, again with a 100 yard zero, the estimated come-ups would be 1.1 MOA from 100 to 200 yards, 2.8 MOA from 200 to 300 yards, 4.2 MOA from 300 to 400 yards, 5.3 MOA from 400 to 500 yards, and 6.6 MOA from 500 to 600 yards (assuming a muzzle velocity of 2984 fps and BC of .304). So again with rounding 1-3-4-5-7, a little closer to the so-called standard. Keep in mind an error of 2 MOA at 500 yards is 10" which could be enough to cause you to miss paper altogether.
What? The point of those comeups is to get you on paper, with the paper being a 60-72" backer, and a 10" error is not going to cause a miss. If you start with a 100 yard zero and come up 2 MOA at the 200 yard line, you will be on paper, and after that stage you will have a good zero. If you come up 2 MOA from that corrected zero at 300, you will once again be on paper. Come up 12 MOA from the 300 yard zero, and you'll be on paper (likely in the black) at 600. I've done this at two cross the course highpower matches this year; I showed up with an unzeroed upper to one, and then a new scope at the next, and my first sighter was either in the black or close to it. Don't do this unless your match includes sighters :).
I showed up at my AS KD with a rifle zeroed at 100, and dope for 200/300. I used chrono data and a ballistic calculator to predict my comeup for 400 yards, and ended up 16" high on the target. That was an easy fix, but my point is that software may be no better (or even worse) than using the generic comeups.
From the center of the V ring to the bottom of the "D" silhouette target used at Appleseed KD events is 6 inches. Your range may use backers that are six feet high. At the range I shoot at, we have a fixed firing line and move the targets out to range using target stands that take a cardboard backer that is not a whole lot bigger than the D silhouette, so yes, a miss of 10" low when aiming dead center can easily miss not only the target but the backer as well.
The last KD event I shot at we shot out to 500 yards and I used an 18" barreled AR and 55 grain 5.56x45 FMJ ammunition. The come-ups predicted by that "standard" formula were twice too much at 200 yards, but of course the hits were still on target at that range. The come-ups suggested by that formula for 400 and 500 yards were much less than what was actually required. It sounds as if Badger498 describes a similar experience in post #28 of this thread.
There is absolutely no point in using a formula that pretty much dated from using 150 grain, 30.06 Springfield, with a lower muzzle velocity and a much higher ballistic coefficient to predict what a much lighter 5.56x45 projectile with a higher muzzle velocity and a poorer BC is actually going to do at range. Unless of course, you want to shoot of a lot of ammo and make many trips downrange to check your target until you get your scope adjusted.
Quote from: pblanc on May 30, 2019, 02:08:59 PM
From the center of the V ring to the bottom of the "D" silhouette target used at Appleseed KD events is 6 inches. Your range may use backers that are six feet high. At the range I shoot at, we have a fixed firing line and move the targets out to range using target stands that take a cardboard backer that is not a whole lot bigger than the D silhouette, so yes, a miss of 10" low when aiming dead center can easily miss not only the target but the backer as well.
So you were using just the repair center without a 3 ring? That would be a…suboptimal KD experience, for sure. Here we are scoring and pasting after one of the stages (must be 400, because I'm looking at holes outside the 3 ring). I assumed this was the standard target.
Quote
There is absolutely no point in using a formula that pretty much dated from using 150 grain, 30.06 Springfield, with a lower muzzle velocity and a much higher ballistic coefficient to predict what a much lighter 5.56x45 projectile with a higher muzzle velocity and a poorer BC is actually going to do at range. Unless of course, you want to shoot of a lot of ammo and make many trips downrange to check your target until you get your scope adjusted.
Agreed, but the comeups for .30 caliber from Fred's guide are 3-3-4-4-5 from a 100-yd zero, if I recall correctly ;). The point of a KD is to make those trips downrange to check your target and get the correct zeros for your equipment, but it's easier if you have a large backer, or at the very least a full target.
edited to attach photo, since the img tag didn't work
Yes. The targets we were using were the same as those available from the Appleseed store, using a "hits count" method of scoring, i.e, it only counts if it hits the black. The paper measures 24" wide and 18" tall. The very top of the "head" of the D silhouette (which would ordinarily be 19" high) is slightly cut off. The black of the target comes all the way up to the top and bottom of the paper, and all the way out to both sides.
The target stands we use are simple metal ones that have two spikes going into the ground. They rise only about 2" above the ground and accept furring strips 4' high. The strips are just about as far apart as the D target is wide, so there is little or no backer to either side of the target. These target stands are light weight so they are easy to reposition and carry, and the spikes keep them from blowing over in wind. We try to mount the bottom of the silhouette target at least 16" or so above the target stands, so that the stands don't get shot up (they do anyway). So we are typically mounting the 19x24" target on a cardboard backer that is about 2' by 2' or very slightly larger, leaving little room for error.
Keeping in mind that the stated goal of Appleseed is to shoot to 4 MOA, which many cannot do, even those shooters who are able to do so with their particular rifle and ammo can be expected to have maximum group sizes of 20" diameter at 500 yards. My particular experience at the last KD shoot was that after adjusting up 4 MOA on my scope going from 400 to 500 yards, and shooting a group of 5 sighters, when I went out to check the target I had only one hole at the bottom of the cardboard backer and none on the target. The actual come-up appropriate for my rifle and ammo was around 6 MOA, so the "formula" produced a 10" error at that range. I could only make a wild guess as to where the center of that sighter group might have wound up on a bigger target and adjust from there. That second adjustment did get me on paper, but still required a third adjustment, and another 1000 yard round trip to check the target, that would not have been necessary if I had used a formula that was closer to the reality of my rifle and ammo.
Quote from: pblanc on May 30, 2019, 03:34:37 PM
Yes. The targets we were using were the same as those available from the Appleseed store, using a "hits count" method of scoring, i.e, it only counts if it hits the black. The paper measures 24" wide and 18" tall. The very top of the "head" of the D silhouette (which would ordinarily be 19" high) is slightly cut off. The black of the target comes all the way up to the top and bottom of the paper, and all the way out to both sides.
Those are the repair centers for the KD targets. You can see the full sized targets in this KD thread:
https://appleseedinfo.org/smf/index.php?topic=54663.0
Yeah, well, those "repair centers" are the actual targets that we use at the KD event at my local range. We use a single target for all sighters and all stages for two full AQTs and cover the holes with black or white pasties.
Quote from: maxwell on May 30, 2019, 01:10:40 PM
I showed up at my AS KD with a rifle zeroed at 100, and dope for 200/300. I used chrono data and a ballistic calculator to predict my comeup for 400 yards, and ended up 16" high on the target. That was an easy fix, but my point is that software may be no better (or even worse) than using the generic comeups.
Bad input. Math and Physics are not debatable.
Quote from: LogCabinShooter on May 31, 2019, 01:13:27 PM
Quote from: maxwell on May 30, 2019, 01:10:40 PM
I showed up at my AS KD with a rifle zeroed at 100, and dope for 200/300. I used chrono data and a ballistic calculator to predict my comeup for 400 yards, and ended up 16" high on the target. That was an easy fix, but my point is that software may be no better (or even worse) than using the generic comeups.
Bad input. Math and Physics are not debatable.
LOL
Ditch the teenie-weenie 556 rounds, change your barrel, bolt and mags and shoot 6.5 Grendel and use BSZ. Score every time. O0
Quote from: B.C. on May 31, 2019, 03:15:02 PM
Ditch the teenie-weenie 556 rounds, change your barrel, bolt and mags and shoot 6.5 Grendel and use BSZ. Score every time. O0
B.C.
Thanks for the advice, but the purpose of this thread is about how best to shoot the 5.56 I chose to shoot my first KD with, and about which ammo weight might give an advantage. I apologize if my wording made that unclear.
As for the concept of MPBR and holdovers for fast shooting on targets at multiple ranges, I'm a fan, and use it for hunting as well as for a gun that I have set up with a dot that I can give to anyone to help aid in defense if necessary. My approach to this KD event was to see how precisely I could place these bullets from this gun under this course of fire, as well as to see actual drop info from this gun with this ammo while shooting at actual distance. The public ranges in my area are 100 yards max, so the rare experience of getting real data was very important to me.
I couldn't care one little bit if others have daily access to long range shooting, or what fancy gun they shoot in whatever caliber of the month they might choose. To my understanding, Appleseed is about turning average shooters into effective marksmen with rack grade guns, rather than taking an average shooter and telling him to go buy a different gun.
As I understand it, BC's graphic isn't showing BSZ, it's showing holdoffs…which you can mix with BSZ to get outside of your range. Why twiddle knobs, though? So you can use the same sight picture (step 2 of the six steps of firing a shot), and not wonder if you used the wrong hash mark in your patented Wizz-Bang Reticle(tm), or held precisely on the same part of the silhouette. More importantly, you don't have to mentally do an affine transform to figure out your shot call, which is a pretty big part of the learning process for KD and wind. BSZ at least gives you the consistent sight picture.
While I'm a confirmed knob-twiddler, there are good reasons to do either one or the other! Fred's guide goes over both of them, at least in the old version you can find online, which has holdoffs.
Quote from: maxwell on May 31, 2019, 02:05:26 PM
Quote from: LogCabinShooter on May 31, 2019, 01:13:27 PM
Quote from: maxwell on May 30, 2019, 01:10:40 PM
I showed up at my AS KD with a rifle zeroed at 100, and dope for 200/300. I used chrono data and a ballistic calculator to predict my comeup for 400 yards, and ended up 16" high on the target. That was an easy fix, but my point is that software may be no better (or even worse) than using the generic comeups.
Bad input. Math and Physics are not debatable.
LOL
Assuming we're talking about 5.56 ammo, 55 gr. 3100 fp, 100 yard zero:
200 yards, 2" drop, 4 clicks up (assuming 1/4 moa turret)
300 yards, 10.39" drop, 13 clicks up
400 yards 26.7" drop, 25 clicks up.
You missed POA by 16 inches (clicks) high? That's error or equipment. If I had to guess, I'd say the scope was already dialed for 300 yards, but was turned an additional 25, bringing you within 1 MOA of POI. I've never seen a calculator off that far. Not even close.
Quote from: LogCabinShooter on June 05, 2019, 03:33:03 PM
You missed POA by 16 inches (clicks) high? That's error or equipment. If I had to guess, I'd say the scope was already dialed for 300 yards, but was turned an additional 25, bringing you within 1 MOA of POI. I've never seen a calculator off that far. Not even close.
Not that it matters, but it was an AR-15 A2, not a scope. The Ballistic app (supposedly using JBM internally) on iOS was wrong, and POI was 4 MOA high at 400 yards. I confirmed this with a friend of mine who's an accomplished benchrest 1k yard shooter, and he came up with the same incorrect drop using my boundary conditions. Ballistic AE got closer, using Litz' G7 coefficients for the 69 SMK (Ballistic only has G1) and adjusting for temperature and humidity, but still not right on. We messed around with this for quite a while, but didn't do a formal sensitivity analysis. It's a model, and subject to internal approximations as well as boundary/initial conditions that you feed in ("bad input," as you said); my academic background in sediment transport leads me to automatically distrust models, so I'm not particularly bothered by this. It got me on paper, and that's what I needed.
Quote from: maxwell on June 05, 2019, 05:09:11 PM
Quote from: LogCabinShooter on June 05, 2019, 03:33:03 PM
You missed POA by 16 inches (clicks) high? That's error or equipment. If I had to guess, I'd say the scope was already dialed for 300 yards, but was turned an additional 25, bringing you within 1 MOA of POI. I've never seen a calculator off that far. Not even close.
Not that it matters, but it was an AR-15 A2, not a scope. The Ballistic app (supposedly using JBM internally) on iOS was wrong, and POI was 4 MOA high at 400 yards. I confirmed this with a friend of mine who's an accomplished benchrest 1k yard shooter, and he came up with the same incorrect drop using my boundary conditions. Ballistic AE got closer, using Litz' G7 coefficients for the 69 SMK (Ballistic only has G1) and adjusting for temperature and humidity, but still not right on. We messed around with this for quite a while, but didn't do a formal sensitivity analysis. It's a model, and subject to internal approximations as well as boundary/initial conditions that you feed in ("bad input," as you said); my academic background in sediment transport leads me to automatically distrust models, so I'm not particularly bothered by this. It got me on paper, and that's what I needed.
Did you have a crono to verify velocity?
Quote from: Lomshek on June 06, 2019, 01:35:31 AM
Did you have a crono to verify velocity?
Yes:
Quote from: maxwell on May 30, 2019, 01:10:40 PM
I used chrono data and a ballistic calculator to predict my comeup for 400 yards, and ended up 16" high on the target.
Sorry I missed that. No idea why it would be that far then off unless the BC was way off or some other input was incorrect. I'd dig deeper into the inputs and settings on the ballistic calculator.
Edited to add this -
I wonder if the click values on your A2 were different than the entered values? Like you said it's academic now just surprising that it was as far off as you observed.
I've used Strelok Pro for a while with velocity readings from my Caldwell (Midway USA) crono for handloaded single fed 80 grain Sierra Match Kings and been pretty much dead on out to 900 yards for drop. The errors I've observed have been from the shortcomings of my cheap scope's ability to dial accurately (or me to count the mushy clicks).
Here's a 5 round group fired prone slung up from my 16" Daniel Defense at 900 yards with a 1-4x Burris MTAC.
(https://appleseedinfo.org/smf/index.php?action=dlattach;topic=55886.0;attach=161568;image)
Strelok predicted 32.3 MOA so I dialed 28.5 MOA on my scope and used the second aiming dot. That put me a smidge higher than ideal on target.
Here's a screen shot of what that looked like with my reticle in Strelok.
(https://appleseedinfo.org/smf/index.php?action=dlattach;topic=55886.0;attach=161572;image)
The group is opening up (I think) because the rounds are going transonic at about 850 yards. Under 800 yards they stay about MOA'ish and are pretty much dead on for predicted elevation.
The big white circle is a 24" dot simulating the target gong at a shooting match I was prepping for.