Most of the time I shoot customer rifles, I try to step out and shoot some long range with one of mine. I generally try to get that first round hit at distance. If you hit, awesome. If you miss, why did you miss? What caused that miss? Was it wind? Was it your dope? Follow it up with a round to get a hit, and learn from it. If you shoot enough and learn enough, that first round hit becomes less difficult over time.

There are also bullets on the market now that make shooting long range VERY easy. If someone tells me they made a first round hit with a 22" 308 Win at 1K, that's pretty good! If someone tells me they made a first round hit at 1K with a 28 Nosler pushing a 195 grain Berger, that's also good, but not near as impressive. The 28 Nosler with a 195 Berger is supersonic to 2000+ yards, so you dang sure better be able to hit 1K easily with the flat shooting and high BC bullet. Those types of rounds make shooting longer range much easier. That's why I'm running the 7mm 195 Berger at 3000 fps in a 7mm/300 Win Mag. It shoots SOOOO good and it's a wind cheating and gravity cheating bullet. I'm about to switch over to the 190 A-Tip and can't wait!

The larger problem with much of the factory ammo is inconsistent powder charges. Inconsistent powder charges lead to inconsistent muzzle velocities. Inconsistent muzzle velocities lead to vertical dispersion at distance. Add to that, powders that are not necessarily temperature stable and you introduce yet another factor causing inconsistent muzzle velocities. All that leads to many people becoming very frustrated trying to hit a target that far out.

Enter in hand loaded ammo, tuned to the rifle, using temperature stable powders, maintaining very tight tolerances from one charge to the next, and factors have been removed. Load that in a well built rifle, topped with great base and rings, holding a very capable rifle scope, and there is one factor that is left. The six inches between the ears of the shooter.

This is more true than I thought and it really is that simple in a certain sense, but the devil is in the details. Honestly, the well built rifle part can even be very loosely taken as well. I'd rather spend more on good rings even than "upgrade" on the rifle sometimes. I hand built mine completely from the ground up with good parts; Savage model 12, hs stock, shilen 308 barrel. Again, I haven't shot at 1000 but my 178 eldm in 308 says it will maintain supersonic out to 1000 and it did well on 10" steel at 600 yards. Fireman really helped me accelerate through my learning curve with reloading to get some killer ammo. As comparison, the best factory ammo happened to be one of the "cheapest" for my rifle was the 175smk Federal GMM (approx $1.10 per shot). I just couldn't get better than about 2.0" at 300 yards. My 308 can do 2.0" 300 all day and many random 5 shot groups of 1.5". I've been told others with a similar combo as mine can achieve 1.0" at 300 yard very regularly. And I'm also flat out admitting my shooting technique still needs alot of improvement.

Don't shoot at game animals beyond your ability. Hogs, coyote, and ferals oh yeah. I have been a handloader over 45 years. Making loads that shoot tiny groups is a hobby. Most of my weapons are also what I hunt with. I like nice glass but do not shoot long range. What I hunt whitetail with would be considered small to intermediate calibers. They kill just fine. Just because I could hit an animal at an extended range does not mean that is ethical. Some of the fine long range calibers run out of steam beyond X distance. Then there is the matter of best hunting bullets vs ones constructed for long range target shooting.
Potting pasture poodles out to whatever distance you can do so is entertaining. Ranchers used to welcome us back in the 70's and 80's. Knob twisting during a hunting situation would compound the ability to make a successful shot. If you want to hunt long range spend the coin on all aspects of the gear and understand ALL the fundamentals. Then there is the matter of doing it often enough that it becomes second nature. Shoot steel at long range. Your not a damn sniper. Do not forget what hunting is. There is a reason some resort to bow and arrow. I am to old for that now.

...and not one 7-08 on that list.

That’s not my game but we shoot very similar rifles. I’ll answer what I can.

Funny thing in equip list....you think the guys that were blank were shooting Tikkas and were embarrassed?

You shoot similar rifles to the guys in the competition link?? I still haven't looked close at all to the link.

A Sub-$450 Bolt-Action Ringing Steel At 1,800 Yards — Mossberg’s Patriot Predator(Link)

1000 for game is most likely unethical for 99 percent

But I say a .50 cal is unethical too for legal game

It’s my own beliefs...

You have to draw a line somewhere.

I know, a 7mm from 100 is, like I said..you have to draw it somewhere

Let's go back to some basics.

If it were possible to make three, 1000 yard shots in a vacuum with zero gravity, would there be linear dispersion between the trajectory of each bullet or are there other factors that could alter the path of a bullet in perfect conditions? For example, are there other factors that might cause a bullet to begin to curve even if passing through a vacuum, theoretically speaking of course?

Outside of a theoretical environment, I can easily see how wind, variation in air temperature, or even varying levels of humidity might alter the trajectory of a bullet.

As Chad says some setups are easier than others. A few months ago I got into a shootoff at 1000 against a shooter using a 300 WM shooting 225gr ELD -M. It was sudden death and we thought he hit first shot but he actually hit the chain. I fired my first and hit he missed his second and I hit again for the win.
I was using the 28 Nosler shooting the 197 gr Sierra at 3080. Here are my two shots on a 1 MOA plate at 1000.
In this case I knew my elevation was close because had already fired 15 shots at a larger target but it had been 45 minutes since I had last fired so the wind was the main question. We are allowed a front rest or bipods BUT no rear rest allowed only resting on your arm.

Let me rephrase my question.

If we take away the forces that impact the path of a bullet once it leaves a rifle barrel, what forces can alter the path of a bullet before it leaves the barrel?

Inconsistent brass prep

Inconsistent powder charge

Heat-big factor

Dirty barrel-excessive copper build up

Humidity


Is that what you was asking dan?

Yes. Thanks for the reply.

My reason for asking is to get an understanding of how a group that's tight at 100 yards may begin to spread out at some greater distance. I was thinking it happens because of a combination of differences that begin inside the barrel and then later as the bullets pass through the air.

A good group at 100 can turn sour at 500 due to velocity variances. That is the #1 reason by far assuming you are shooting a cartridge that is stable at that range.

The list is very long on what items cause groups to open up at distance. We've covered most of them. I had one that puzzled me on my 270 Win for a while. I upgraded (what I thought was an upgrade) my hunting scope to a Zeiss Conquest many years ago. It had the target turrets so I could dial easier for longer shots. The 270 was easy sub moa and shot very well at 100 with some 130 SST bullets. Once I got out to 300 and 400 yards, my groups opened up dramatically. I went back to 100 and they were tight again. I went out to 400 and the opened up and were very large (large for me at least). I had an extra scope with me so I swapped scopes (advantage of having a picatinny rail on everything). I zero'd and shot to 400 again. Groups were tight and on target like they should have been. I read up on the Zeiss scope, which did not have a parallax adjustment knob on the side. That scope was known to have issues with parallax when you went to longer ranges. I sold the scope and went to something that was a better scope. It wears a Leupold VX-7, 4x-16x with the collapsible target turrets with parallax adjustment. I love that scope as a hunting scope and it functions perfect with VERY clear glass. It's also the only Leupold I own. So, there's many things that can cause groups to open up once you start shooting longer ranges. Those items can vary depending on your set up and how you shoot. To me, it's all about minimizing those items that CAN cause issues at distance.

I had a customer call me about some groups they shot at 1000. There were about 5 or 6 guys shooting, and most were running a 6.5 CM. One guy had my match grade 6.5 CM with 140 ELDM. The rest were shooting factory Hornady ammo. They had multiple steel targets at 1K and each had their own steel. The guy running my ammo had a 3" tall group at 1K yards and was wide right and left due to wind (he self admitted he wasn't good yet with the wind calls). The other guys shooting the Hornady factory ammo had groups that strung up and down the height of the IPSC steel target they were shooting, plus the right and left from the wind. My point is, my custom ammo where the powder charge is weighed to within .02 grains consistency (to the kernel of gun powder) allows for VERY tight tolerances and provides you very low extreme spread (ES) and standard deviations (SD) on the velocity. Each round will be as identical as possible to the next round. The factory ammo WILL have a large variation in the powder charges inside the case which give you a high ES and SD on the velocity, which causes vertical stringing at further distances. Most people do not get to see this difference in the quality of the ammo they are shooting. It's something that may not be seen only at 100 yards. But 99% of shooters gauge the quality of their ammo at 100 yards.

I'm trying to understand how a scope can impact the ballistic performance of a bullet when it has no impact on anything that drives it. I'm sure it has something to do with geometry and differences between the axis of the scope and barrel but would enjoy seeing an explanation that most would find easy to follow.

From the Optics section:
Parallax:
Parallax is essentially an optical illusion. Parallax presents itself as the apparent movement of the reticle, in relation to the target, when your eye moves off center of the sight picture (exit pupil) or in more extreme cases it appears as an out of focus image. It indicates that the scope is either out of focus or more specifically the image of the target is not occurring on the same focal plane as the reticle. Maximum parallax occurs when your eye is at the very edge of the sight picture (exit pupil). Even when parallax is adjusted for a designated distance, there is an inadvertent error at other distances. Most brands of scopes that do not have a parallax adjustment are pre-set at the factory to be parallax free at or around 100 yards; rim fire and shotgun scopes are set at or around 50 yards. Most scopes of 11x or more have a parallax adjustment because parallax worsens at higher magnifications. Generally speaking parallax adjustment is not required for hunting situations and is primarily a feature used and desired by target shooters. A 4x hunting scope focused for 150 yards has a maximum error of only 8/10ths of an inch at 500 yards. At short distances, the parallax effect does not affect accuracy. Using the same 4x scope at 100 yards, the maximum error is less than 2/10ths of an inch. It is also good to remember that, as long you are sighting straight through the middle of the scope, or close to it, parallax will have virtually no effect on accuracy in a hunting situation.
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https://texashuntingforum.com/forum/ubbthreads.php/topics/3371190/1/riflescope-school

Thanks for the quick reply back and explanation.

So if I understand this correctly, Parallax Error doesn't effect the bullet itself in any way, but simply causes the shooter to position the rifle incorrectly and a take a bad aim when aiming at more distant targets. If so, it's really not the bullet paths that have opened up at an extended distance but is what happens when the shooter is unable to aim accurately due to the Parallax Error. Do I have it correct?

Another big thing I've seen is the sun and the sun's angle in relation to your shooting direction. I try to zero my match rifle on a cloudy day or early in the morning or late in the evening when there is no sun. This will avoid any POI shift due to the lighting angle changing where the target actually is. When you have a match rifle that is capable of one hole accuracy at 100 yards, you will see this. I've chased my tail on a proper zero on more than one occasion before a match. Once, before a big match at Rifles Only (RO) down in Kingsville, I had been to the range on multiple occasions shooting long range and making sure my zero was DEAD on. My bullet was impacting about half a bullet hole left of dead center. So, the round was hitting a tiny bulls eye, but about half a bullet to the left most every shot. You can't adjust this since a tenth of a mil (.1) is larger than the difference of the half of the bullet is left. So I would hold on the right edge of a tiny bulls eye to hit dead center, and I'm good. Over the years when shooting at RO, we would confirm zero the day before the match or the morning of. In the afternoon zero, the sun would be coming from the 9 o'clock position, bright and shiny. We would shoot from a slightly elevated berm in the prone position at 100 yards for zeroing. I would be about a tenth or two tenths (.1 or .2 mils) high and left EVERY TIME!!! So I would get all nervous and reset my turrets to this new zero. Then during the match, I would chase my shots being off a tenth or two for a half day. Finally, I reset my turrets and went back to my known zero when I was back home. Now I would be on target and making solid hits from then on. This issue was 3 things. The sun, the suns angle, and the mirage coming off the ground when shooting prone in the hot afternoon was causing a POI shift. Since I have shot multiple matches there and train down there every year, I now know that is a common issue at there 100 yard berm and do NOT make the adjustment to change my zero. I simply hold the difference and keep my known zero. This has saved my butt on multiple occasions.

Basically, yes. That's why I mention you are only as good as your rifle's "system". System meaning, rifle, ammo, optics, and shooter. Where is the weak link in YOUR system? Then fix it. This is why I'm not a big fan of the BDC turrets for shooting out past 400 and 500 yards. The BDC turrets lock you into a set program of trajectory data based on a one environmental condition. If those conditions change, then so does your drop, and the BDC turrets will not be correct. I've seen this MANY times. The weak link in that "system" is the BDC turrets. Guys spend thousands of dollars on a high end, rifle, high end scope, good custom ammo, then create a BDC turret and induce a a lot of error factor when the environmental conditions change. The answer, learn mils (or moa) and make that adjustment. The BDC turrets do work out to 300 and 400 yards with not a lot of difference in trajectory change in varying conditions. But the further out you shoot, the more change there is and will pull you off your aiming point. I'm just not a fan of them.

The list is VERY long on what all effects a bullet being off target. The skill is knowing what's causing it and fix it, or knowing that something CAN cause an issue and avoid it all together.

I am going to try to answer this as technically correct as I can, including rigid terminology that I learned.

1. If it were vacuum and literally no gravitational affects, then the bullet would literally go on forever in a "straight" path. So this is the highest level of abstraction for free body movement, bullet or otherwise. (side note: light theoretically does this because it behaves both as a particle and a wave. but a big debate since in physics is why the "blackness" in space. No real good answer still, just of a bunch of unprovable theories.). Btw, this presumes the other 3 fundamental forces are about the same. I never really understood those anyways.

2. Next steps are start adding layers of reality, starting with gravity. Imagine standing on a fictitious surface/ground that is literally flat in all directions, BUT has earth's gravity. NO air, so vacuum of space. If the barrel was perfectly level at whatever height you wish, you can calculate exactly where it will hit the ground. You'd have to know the velocity, both magnitude and direction, and use what I was taught to call projectile motions in physics. In fact, if you just knew the angle of the barrel vs the ground, then it doesn't matter, u can predict exactly where it will be at every moment in terms of 3d space and time. It's not hard and is the basis for artillery shooting. that's how cannons can be launched several mile onto an anthill. I can do this level math. Btw, if you had a level barrel and shot the rifle in one hand while dropping the same bullet in the bother at the same height, they would both hit the ground at the exact same time.
If you now stand on earth with no air, then you can do these really higher order gravitational equations in calculus to understand the changing effects of Earth's gravitational strength/force (because it's a radius driven equation) vs the curvature.. This level of math is way too hard for me to have ever understood beyond that little punchline. But the foundational problem/equation is still projectile motions with constantly changing gravitational situations. This is how you account for the Coriolis effect for those who shot extreme long distances.

3. add air, 100% perfect still air with NO changes. It's as basic as drag. The concept is easy to understand. Anyone who's ridden bikes into the wind can testify to air drag effects. It's really what limits things like the land speed record. However IMHO, it is a bit of magic and science still. It is an empirically based kind of science, meaning the equations that govern were derived after making the observations. We studied it in ME as thermo-fluid mechanics. So start with the idealized flat surface from 2. but the air is a constant pressure, temperature and chemical content throughout the whole expanse. These are very hugely idealized conditions. You can apply drag force equations with the fluid of your choice, air, and most of the drag coefficients are knows. There are several coefficients/factors for the air and the object itself. In the world of shooting, the factor that accounts for how the bullet is shaped is referred to as the ballistic coefficient. So if you imagine the bullet in some single instance in time at some speed, then you can calculate the drag as a force value and then understand how much it will decelerate to the next moment. Now try doing this for every continuous moment, while simultaneously doing the math of it constantly slowing down. As before, I can do the first level math for a single moment but can NOT do the math for the continuous over time and deceleration. If that wasn't hard enough, now imagine if the conditions of the air change, then you some how have to figure all the above and include multiple iterations/simulations for all the air condition combinations you can come up with. So that's how you start accounting for humidity (chemical content), temp, elevation (denisty), etc.

4. "Wind" as most people here refer to is usually talking about the wind that causes the bullet to go side to side. Mostly the same principle as 3 but the wind/air in motion is acting on the bullet in that direction. Easy in concept, much harder to quantity. In my experience, field observations/notes from yourself and other shooters seem to be more useful. I ran some numbers once and it was so off in orders of magnitude it was a complete waste of time. The difficulty is trying to quantity all the variables. Not worth the exercise for a simpleton like me.

So basically if you start projectile motion equations, then you can start with adding second order functions (gravity and air drag effects in both directions). Again, one can know precisely how fast and exact point in 3d space of a object with project motion equation within idealized conditions. So second order mean instead of values for the projectile motion equation, next you assume all the idealized conditions are NOT true and you make a whole other set of of mathematical equations to substitute the values used in the idealized scenario.
From what I understand, some mad genius name Bill or Brian Luntz or Lidtz or something like that did this and has now become the basis for all ballistic calculators.

As for the "what happens before and after it leaves the barrel" almost have nothing to do with the each other. It really comes down to what point you deem the gases are no longer acting on the bullet. Literally the instant the back of the bullet is in line with the end of the barrel is convenient but i could still argue at that instant the gas will still push it. Even then it becomes of question of how tiny of a time interval you're really talking about. If you don't think ihow small of an interval makes a difference, then watch high speed camera and see how much happens within thousandths of a second. So realistically at some point near the end of the barrel where the gas don't push the bullet anymore, whatever the rifle would have done to the bullet is already done.

A lot of good information has been shared no doubt.

So then, let's consider a scenario where a clear sheet of plastic has been placed 100 yards at a point between you and a 1000 yard target, the purpose of which is to mark the location of each of three bullets as they pass through it. Given you're using the most consistent bullets and powder charge achievable and have made corrections for parallax error, any differences in where each bullet impacts the clear sheet of plastic at 100 yards are the result of corrections made due to differences in wind speed and direction, as well as other environmental factors.

This scenario also seems to help one understand how a very tight group at 100 yards doesn't necessarily produce an acceptable group at 1000 yards. However, if all the environmental conditions were the same so that the same compensations were made for each shot, would not the 100 group be very close together? Whatever the case, it would be an after-the-fact grouping that would be of little significance to the shooter.

A rifle/load/optics/shooter system that shoots very well at 1000 yards will generally shoot well at 100 yards but one that shoots very well at 100 yards does not necessarily at 1000 yards.