Home Forums Hunting & Shooting Ask The Gunwriters Acceptable accuracy , out to 400 yards

Good answer, but my question was more about physics than math. How do we account for the drift that varies more than the square?

I didn't "account for it", I simply observed that it didn't quite fit the pure quadratic model. I'd have to study up to be conversant with a proper derivation.

We may have been posting at the same time, but I addressed this above in post #17903025.

... and where one can put that round, under field conditions.

Far more a rifleman problem than rifle.




GR

Thanks!

Back when I was young, most rifles that were affordable, and the ammunition of that day, would be lucky to produce better than a 5-shot 2.5” group… I guess nobody ever killed deer at 400 yards back then.

Well, one thing's for sure: Deer hadn't yet shrunk to the size of prairie dogs, as they apparently have today.

Well said, I like to be able to shoot my rifle any time I pick it up and with a clean, cold barrel shoot a 1” shot. Put gun up for that day, go back another day and do the same shot and it be 1”….same conditions as close as possible. If will do that I will go hunting and be confident that it will put it where I aimed on any shot I take out to 300 yards because I know where it will hit out to that range. Now, if I take a 400 yard shot I might can make it and I might not….have hit iron from that distance BUT I might not press the bang button because I might miss and I don’t like too miss. Anyone that can shoot at that distance and know they can make it is a good shot….I don’t know that yet.

I guess I'll be the guy that has to say it:

Maybe people hunted closer back then, too.
My deer are closer to archery ranges on average, but everyone's terrain is different. I never see a nice buck standing out in a field. It's usually some nasty brush-choked schit-hole.

Or hustling across a lane/road in the thick stuff without checking up. That's what I run into fairly often, especially in the rut. 3-4 seconds to spot him and mentally range him, get him in the scope, judge him, and make the shot (or pass).

Lord have mercy you nerds! Save it for rocket science.
Double the yardage, double the MOA/Mil wind correction plus a click or two.

Word for word, letter for letter, this^^^^^^^^^^^
Both posts

I agree with everything above, and I'm not a looney!

I have a M98 in .30-06 that will repeatedly put 3 into an inch at 300 yards, with no wind, and a good solid rest. Under those conditions, I'm still - as shooter- maxed out at 500. I just won't shoot at an animal beyond that. I once , using the snow machine windscreen for my rest, killed a caribou right at 300 yards with it, and a few seconds later, after another ranging, a second one at 433 yards. Both bullets went where intended.

The 11th bullet down that barrel killed one at 370 yards.

I'd consider 2MOA to be aceptable to 400 yards in my hands, under above conditions.

But I wouldn't be happy about it!- After 30 years, and literally a ton or more of game, I fixed my 700 .243 from 2MOA to MOA. Haven't killed anything with it since.... Nor anything previous over 200 yards.

I used it to take my first Dall ram. It was sufficiently accurate at 20 yards, and the next year, for one at 100 yards.

How to tell us you don't know how to shoot in the wind.

This is completely wrong.

Do you not see the laughing face behind this....

I’ll take some tutelage on the question of wind shooting at 400 yards, if I’m doing something incorrectly.

I’ve always used this Kentucky windage method and it has produced rapid death. Shooting a 30 cal 180grain bullet at 400 yards into an ungulate in a R2L or L2R wind up to 20-25MPH with a standing broadside animal.

Me, wanting to place a shot approximately 6-8” behind the shoulder - I will hold on the rear muscle crease of the shoulder and let her fly. I’ve never put a tape measure to the entrance hole, but my hand stretched out has either touched or just about touched the hole.

I happily admit that I will shoot in this wind situation out to 500 yards. Anything nearing 600 yards, If I can’t close the distance. It’s a pass for me.

🦫

NO one wounded or missed either.

IMHO I can handle a less accurate gun on targets and competition because I can control my rest and wobble a lot easier.

On animals your wobble area is a lot more than most will admit. Even my slung up wobble area while competing was over .25 moa wobble.

I"ve seen wobble and pulse beats be as big or bigger easily than group size.

So my take on this. 400 yards. I want more accuracy than most will. I accept less than some will. My current test is a 4 inch diamond and I usually shoot 100-500 appx 100 yard increments. Off of a rest. One shot each distance. If the gun can't stay in that diamond as long as I'm solid on the wind, then I'm still working on the long end of that load. It tests the sig box drop program too constantly.

So lets just say if I took say 2 moa instead. 8 inches at 400 yards. Then lets ad in an honest average field wobble of 2 moa again. 16 inches. And you err on the wrong side of the wobble on the wrong average shot.. at least 16 inches off at a minimum if my brain is working this morning. Then add in a wrong distance, angular issue, wind guessed wrong... it adds up really quickly IMHO.

Clay targets seem like a fair test at some of the mid ranges like 300-500 yards as a target.

All of that said if I can't control the wobble part on my end at any distance I just won't shoot. We have those dog size deer in TX everyone makes fun of. A good size kill zone is going to be not quite a volleyball in size. Not lots of room for error.

Just my simple minded thoughts. More accuracy can never hurt. OTOH I see folks show up with 10,000 dollar plus rigs all the time that aren't sighted in and then can't even make use of what they have.

Maybe the better question is how much human error will you accept at 400 yards?

It can't be the same for all different bullets at countless different velocities.

The BC of a bullet will impact the rate of how much more it moves laterally downrange due to wind compared to how much it moves in the first 100 yards. With a lower BC bullet, the bullet slows down more quickly. Thus, it takes more time for the bullet to go a certain distance (and that is compounded the further out you go) and thus there is more time for the wind to move it laterally per distance it travels downrange. A higher-BC bullet will be moving faster downrange. So, the wind will have less time to affect it per unit of distance out at, say, 600 yards compared to how much it moves laterally during the first 200 yards--compared to a lower-BC bullet.

So, it can't be a pure quadratic function. It varies depending on all of the circumstances, including the BC of the bullet and the initial muzzle velocity.

As Jordan Smith posted above, wind drift is dependent on time of flight and wind speed, so it is independent of distance of bullet flight. As you state, muzzle velocity and BC will determine TOF at a specific distance.

Good post rost. I can definitely understand that. I see this thread pop up occasionally, but rarely read it. Yours makes a lot of sense, as I was thinking this morning that there is a difference between accuracy and precision. This thread is about accuracy, at 400 yards. I thought about it more and realized it should be about how close to POA you are, not group size. We always want to focus on group size, that would be precision, not accuracy. For me, I want to keep all my shots within 1 moa from POA (where I want to hit the critter). That is roughly 8 inches (diameter circle) at 400 yards. If you fall out of that 1 moa requirement you place on yourself, it's time for more practice. As you pointed out, that is the "human error" and "wobble" that is affecting where your bullet is landing. Also keeping in mind this thread is about 400 yards. 1 moa may be too much for a 700 yard shot and extremely small for 100 yard shots. 700 requiring more like 1/2 moa from POA, or roughly .550 MOA to remain within that 8" "volleyball" sized kill zone. Then at 100 yards, that 8" kill zone only requires 4 moa accuracy. Most guys/hunters should be able to do that offhand. If not: More practice... That is my take on accuracy. I would have posted pics for a better explanation, but some guys just get pizzed!!!! These are also requirements I place on myself. I strive for 1 shot kills. Others mileage may vary.