what is considered good,excelent,poor for a big game rifle at 450 to 500 yards accuracy wise

With lots of practice at 400-500 yds under field conditions, a rock steady rest, little or no wind, and some fair ability at range estimation, hitting a deer/antelope sized critter somewhere behind the shoulder is fair accuracy. Without the forementioned conditions and criteria, better judgement would win out over any claims of accuracy.

Casey

If you, your rifle, and your ammo are not MOA at that range, don't take the shot. The animal deserves it. Now, terminal performance of the bullet is a whole nuther matter. sundog

Post deleted by steve y

Theoretically, if your rifle will do 1" at 100 yards your bullets will impact no more than 2" from the point of aim at 400 yds.



Here's the rub- that's with identical bench-type rest and PERFECT shot conditions- no wind, mirage, etc. Factor in whatever shooter induced error (breathless, pulse, awkward shooting position, poor rest, etc., and even with a rifle that is only 1.5 MOA the actual shot conditions quickly beome that limiting factor in regards to range. Then factor in the game conditions- running, shot angle, etc.



It quickly becomes obvious that we obsess too much about big-game rifle accuracy.



You will only know by shooting off (of ) your hind legs and with field-type rests what shots you can be confident of making.



Any rifle that does 1.25 MOA or better is a keeper for any longish big game shots of the sort you speak. Mainly because unless you burn one heck of a lot of 500 yd. practice ammo you'll be missing and wounding game regularly regardless of the rifle's accuracy.

Steve
He hasn't done much distance shooting has he?
Loads that group tight (>1MOA) at 100yd will often fall apart at longer ranges (<3MOA) , while loads that group tight (>1MOA) at longer ranges are often only "acceptable" (1.5MOA) at 100yd. You won't know what your load does until you try it at all the various ranges.
This is only 1 of the reasons that those of us that shoot longer distances state that you must field practice at the intended ranges.

My definitions for a 500yd rifle.
Excellent - a rifle that will hold .5 MOA or better at that range (what it will do at 100yds doesn't mean squat, so don't assume a rifle/load that shoots .5 MOA at 100yds is going to do it at longer ranges).
Good - holds 1 MOA or better at 500yds.
Poor/unacceptable - anything over 1 MOA.

Of course this is from a bench just to test the rifle's ability. Your shooting ability and how good of a rest you can find will be the biggest factor when it comes actually making the shot in hunting conditions.

Squirrelsniper pretty much covered the fundamentals.

Quote:

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If your rifle will do 1" at 100 yards your bullets will impact no more than 2" from the point of aim at 400 yds.

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That is true only in lab theory. The reactions and comments above to that statement tend to make one believe that reality is a different world. The list of factors that assault the theory is longer than I care to get into at the moment, and fills many chapters in books about long range shooting.

I do not understand this point if view, IMVHO a long distance shot should be a rare exception.
I like to go near the game without alarm it or ambush the game not seen and not heard making it coming in a very close range.

This is caused also by the impossibility to make training at long distances here in Italy. And if I can not test and zeroe my rifle, I don't risk a game wound.

Sorry to freak you folks out. I thought all here would immediately assume it is strictly a geometrical illustration. I edited my original response to avoid further piling on. Call me a coward.



I don't know if my 665yd range qualifies as long in Tailgunner's book or what he calls "a lot" (I'm sure I've neiher the experience or ability of many here) but I can clearly see my few .5 MOA@100 rifles "spraying" 5-8" groups onto the steel plate. I'm quite aware of why I'm not seeing 3.30" groups at that range. And while I concede some rifle/loads show improved accuracy at range I doubt that a, say, 4MOA @100 rifle is going to put a bullet "to sleep" and give you little-bitty groups @ 500 and make a LD game rifle of it. Possible, I guess. It is a consideration in certain competitive shooting events but I doubt it's ever dramatic enough to be relevant to big-game accuracy. Loss of bullet stability is of course perfectly relevant.







Garydn,

Hope you got my point, even if others didn't. In fact by attacking my point of geometry as optimistic they actually helped make it.



All others factors equal, a .5 MOA rifle will increase your range on big-game by only a few yards over a 1MOA rifle. At 500yds using this simple geometrical comparison the more accurate rifle places the bullet only 1.25" closer to the point of aim. A difference that is quite marginal under field conditions. Unless you intentionally take nothing but long shots from portable benches you would be lucky to live long enough to see the advantage of that last half-minute of angle on big game under field conditions.



The REAL-WORLD translation of all this- You will likely never have to pass on a big-game shot with your MOA rifle at 500yds in the field believing you could have made it with a .5MOA rifle.



To prove it shoot any .5MOA rifle with its pet load and then with loads it "hates" (same bullet and velocity but say 1.5MOA) on an 8" bull @ 500yds off bags and THEN with both loads under identical range conditions but with a field rest and you will see what I'm saying. Unless an INCREDIBLY dramatic sleeper effect that Tailgunner speaks of is in play I'll wager you'll see your misses from field rests vs. benchrest range FAR beyond that 1MOA (actual, not theoretical) accuracy difference- evidence of much more shooter error and shot-to-shot range conditions than rifle inaccuracy.



This can be tried at nearly any distance with any rifle. Bag the the rifle and fire some groups, getting an average. Call that group size your bullseye, then switch to a field rest keeping everything else the same. You'll find that from a field rest there will be a large portion of misses that would not have been "kills" regardless of ANY improvement in accuracy.



For example done at 500yds: a rifle does 8" ave off bags. Then from a field rest you will find some of your misses are further than 8" from point of aim, illustrating that even a "perfectly" accurate rifle would not have made those "killing" shots.



That all rifle/load combos are individuals and don't necessarily hold their MOA (better or worse)is true. And that all shooters should practice the shots they will take on game is true. But unless certain assumptions are made discussions get mired in minutae and the questions such as yours are rendered pointless. The law of diminishing returns applies here and until we get laser guns it will apply to hunting accuracy. (Oh Lord don't let someone jump in about gravitational effect on laser beams. )



Of course you will need to test the hunting load at long range simply to know the bullet is stable. And naturally your abilities at those ranges must be determined as well.



Finally your personal feeling about what is an acceptable miss/wound rate will have to be settled upon seeing the results of these practice sessions.



INCOMING!

I agree that it in theory it would seem that a rifle which is capable of 1 MOA at 100yds should also be capable of 1 MOA at 500yds, with the only variable being the shooter's ability to judge the conditions and make the proper corrections. However, the theory just doesn't hold up in practice.

Just as an example, I have one rifle/load combo that I frequently use for long range because it is very accurate for that purpose. Said rifle/load combo will hold .5 MOA and slightly under at 500yds. But... move the target in to 100yds, same day, same conditions, same load, readjust the scope for zero parallax and shoot for group. WTF , it struggles to stay under 1 MOA at 100yds. Now maybe my shooting ability and wind reading ability just goes down the crapper as soon as I start shooting at close range, but I highly doubt it.

I've heard various theories on why this sort of thing occurs, but I've figured out one thing... I do better if I just shoot and pay attention to what really happens and forget the theories of what "should" happen.

What kind of rifle / load / rest do you use to get a .5 MOA 500 yard group?

Steve, you are missing a few points but it's not a big deal, and you ain't been flamed. We're just BS'n around the fire IMO. You have touched on a couple of aspects of exterior ballistics in such a way that I'm thinking you have an interest, if not the total picture. It is way to complicated to get into on the forum, but if you'd like a couple of book suggestions shoot me a PM and I'll get back with you.

Hey! here's a question...
Based upon the Heisenberg Uncertainty Principal
(you cannot observe something without changing it)
now the question
How much deflection is caused by hitting a paper target? The reason behind the question. Can you put a target every 100 yds and have it represent the true flight path of the bullet?

There have been MANY posts suggesting 300 yds is a better test of a rifle than 100 yds. I've seen a good write up on the precession of the bullet due to the 180,000 RPM rotation. which would explain a loss of accuracy but not precision.
(but I've been drinking )

If I could get into a good solid sling supported prone position with a rifle I knew well and had confidence in, I would be comfortable taking a 500 yd shot in good conditiions. Whew! That said, I've done it at 600 yds in big bore matches at the Nationals where I've shot a lot of groups smaller than 8 inches. (note: NOT bench rest.) I've shot free rifle at 300 meters from kneeling and standing. Would I shoot at a big game animal with a rifle and ranges like that? No way. Mostly because I probably wouldn't kill it outright, but also because I would rather shoot one closer so I wouldn't have to drag it as far.
All I can say is; I'm glad you guys weren't around in the seventies at the Nationals. Lones Wigger, Pres Kendal and Maggie Murdock (not to mention me!) could have packed up our bags and gone home without burning up a few bricks of Eley Tenex.

Some, probably depend on the nature of the paper.

Not precisely, but if the paper was very flimsy it may closely approximate the None-HUP, within reasonable range and with minimal obstruction(s). Conjecture on my part but upon passing through the paper the sonic shock waves are disrupted, and this will momentarily affect BC. Shock wave form relates directly to drag.

Send me some of what you've been drinking and perhaps I can understand the last paragraph. George Dickle by any chance? It does that to me too, but HUP requires all things be equal.

A bullets Sg(gyroscopic stability factor) is a factor of more than just RPM, and as such RPM has no more or less influence on accuracy or precision than the phase of the moon. Precession is the result of external/internal forces upsetting a gyroscopically stabilized body and does not occur otherwise. Do not confuse what benchrest competitors(short range) do in regards to twist rates as the holy grail for practical accuracy. They like to walk the ragged edge of minimum Sg, because slower twists induce less distortion in a bullet as it engraves the rifling. This approach results in quick damping of the fast cycle precession but may in fact aggravate slow cycle precession.

I don't know if any of this helps or not but it's free so it's worth at least what you spent on it. All three disciplines of ballistic science are very complex, and detailed discussion of the broad subject of interior ballistics is rather difficult on a forum. I know a few books if you're interested.

300 yards may or may not be superior for evaluating a rifle's accuracy, common sense is required.

when i first posted this i was curious as to what a good group should be i am shooting a 338 ultra mag with barnes triple shock, shooting off the hood of my truck with sand bags i set a target at 485yds averaged 3.25,shooting through the trees makes it a little chalenging,have a leica rangefinder plan on trying out to 700yds if i can find a place where i donot have to walk so far to target.

Gardn, 3 1/4 inch groups at near 500yds is excellent. Some might frown on a 4 wheeled shooting rest during hunting season but lots use them. You might also do a little shooting prone, sitting and off a bipod too. What type of load are you using in your 338 Ultra?.......DJ

Guys, this is really interesting stuff! I've been shooting for years, and have seen how bullets behave at long range (tracers at night)...

I figured there must be some way of mathematically 'modelling' bullet flight, but for me, it would be too complex... like many others, I have found that the 'theory' isn't reflected in the reality.

Whilst I don't normally take long shots, there are occasions when it has to done (terrain, etc.,) so I just did what someone else suggested... set up some targets at various ranges and had a go. Learnt a lot...

Okay, VELOCITY DEVIATION.

I have read of, but not experienced that influence. Not because I'm immune to physics mind you, I just haven't done any 1000 yard shooting off a bench with a precision rifle. What I have read would lead me to believe that a 10 fps ES in a string will result in measurable vertical dispersion at that range. Other influences contribute based on that spread, but I do not think it can be said that "X" velocity spread results in "Y" vertical stringing.

Here's a few other things to deal with:

Yaw of Repose
Tractability
Variations in meplat shape
Wind(Yes, a cross wind results in vertical dispersion as a function of Sg.)

There are other issues but that would do for now I suppose. If you are unfamiliar with these try: http://www.nennstiel-ruprecht.de/bullfly/index.htm#Formulas

Gary, I'd say that shooting groups like that off a pickup hood probably qualifies you to own a big ranch out west somewhere that is infested with 'yotes. Keep up the good work!

You originally asked for accuracy info for big game rifles at 450 to 500 yards. Later you mention some groups you've shot at these general distances.

There is a difference between accuracy and precision... a precision rifle/ammo/shooter setup will print a small group but that's of little to no consequence for hunting unless there's some level of accuracy. Accuracy is how near a given mark the round or rounds impact.

Something can be said for having an non-precise rifle at long range if the shooter's accuracy is poor but if the shooter 's accuracy is significant this can oversome a less precise rifle setup.

Here's a graphic I linked to to illustrate:



For my purposes I decide what I am capable of by using a 2 MOA rule. I transpose a 2 MOA circle onto the vital zone of the selected/desired big game animal. If that 2 MOA circle is completely inside the vital zone the animal is inside what I consider my range limit under conditions that I feel are appropriate for my shooting. As an example, I don't shoot any further than about 600 yards at deer as I have selected a 12" to 13" kill zone for them... 2 MOA x 6 (600 yards) = 12.5". I've settled on this 2 MOA value as 1 MOA for the rifle/ammo/shooter and the other 1 MOA (.5MOA on either side of center) as a conditions buffer. The rifle/ammo/shooter precision is easily 1 MOA but I certainly don't want a 6 inch group anywhere other than in the vitals area.

Given good shooting conditions I believe that excellent precision at 500 yards would be something under 5", good would be between 5" and 10", poor is something larger than 10". But again, this precision counts for little if the target is missed.

Thanks for posting that, Dave. 99% of hunters don't know the difference. I get more joy from accuracy these days than precision (putting all the bullets in the center of the bull, even if the group isn't quite as small as others I've shot that haven't been in the center of the bull).

Of course you need both to some degree and precision is the best way to determine the potential of a rifle/load combination. But it doesn't mean much if you can't get those little groups where you want them.

So often I see people here talk about shooting groups that could be "covered with a quarter." That's great, but could they actually hit a quarter with every shot? As you know, the latter is much more difficult.

As to velocity variations, it depends on what you consider "long range." It seems that in this discussion we've been considering 500yds as "long range." In that respect, I've never had that much of a problem so long as the ES was somewhat reasonable. Of course a good shooting load with zero deviation would be great, but I don't feel it's necessary to strive for single digit ES and SD for shooting at 500yds, so long as the numbers aren't horrible you can do just fine. Of course at greater distances the ES and SD does become a serious issue.

As for accuracy versus precision, it is a good point and some shooters don't understand that great groups don't mean anything unless you can place those shots where you want them. I've just always had a bad habit about assuming that people automatically know they need to be able to put the shots to point of aim.

I met some BR boys up in Dublin, Ga. some years back, one of them named John Henry. He builds bench and hunting rifles. Anyway, these guys play this really sick game at the 100 and 200 yard lines. Notebook size target with 7 1/8" black dots, three down each side, one in the middle. The middle one is their sighter, the rest for record. What they do is "dot" the dot so to speak. .22 cal rifles and if you leave a trace of black from one of the dots you likely won't make it to round two. They do the same thing at 200 yards but not with quite the same precision. Sometimes they can actually leave a trace of black on two or even three dots and still win. I am humble in their presence.

Don't know what the game is called but I'd say you have to be on top of your game to be competitive.

Wow, this thread made a comeback....



DJ,

Quote:

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How about Parallax? On a scoped rifle the with non-adjustable parallax the scope is optimized for a particular range.

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I'd consider parallax unrelated to the rifle's accuracy.



To all:



I've probably done a poor job of relating my views on an admittedly esoteric and untestable premise.



My premise is that when a group is fired, only a certain portion of that group is attributable to the rifle's inaccuracy. Call it accuracy potential, and consider the rifle alone as a firing device which gives a projectile spin and direction. Assume it is in perfect order and without non-inherent erratic behaviors (like striker fall or bedding issues).



Let's say a 100yd. 1" group is fired and the rifle's inaccuracy is responsible for half, calling that "x". So x=.5MOA



Then the same rifle and load is fired at 1000yd. getting a group af 12".



It seems to me the rifle's contribution to inaccuracy will be no more than .5MOA, which at 1000yds. is 5", leaving 7" for all other factors. (assume MOA=1"at100yds)



So while at close range the rifle's inaccuracy contribution, expressed as a percentage, is great, and at longer ranges it is smaller, it is actually a constant expressed in terms of an arc, or MOA. At the muzzle for instance, with a perfect rest, the rifle's contribution to inaccuracy approaches 100% because all other factors are essentially eliminated.



That's my premise anyway.



I realize now that applied directly this premise does not account for the "sleep factor" but that phenomena may actually be a product of the bullet being optimally stabilized for a range different from the one being shot. But to relate directly it would have to be known whether the bullet is outside the arc at shorter ranges because of the rifle or because of the bullet.



But if a 2MOA@100yds rifle will "sleep" into 1MOA@200yds. I believe it very probable that a load combo can be found to achieve at least 1MOA@100yds, (assuming other inaccuracy factors the same) since the rifle is assumed to have .5MOA capability. But if there is no bullet or load, either actual or theoretical that can make an accurate LD rifle shoot within that arc at shorter range for reasons solely attributable to the rifle, then my theory goes in the toilet and well, it's been fun.



I'm perfectly willing to accept that it may be a false premise, especially since until we have perfect bullets, range conditions, and machine rests to remove all inaccuracy factors other than the rifle itself, it is untestable.





garydn,



My apologies to you and others if I started a rabbit chase; I was approaching your original question from the standpoint of the rifle's accuracy potential, and with no other factors, as things like range conditions and shooter ability are kind of irrelevent to the question as they have to be judged by the shooter himself.

The upshot of my longwindedness is that if you have a rifle that will shoot consistent 1MOA@100 groups, I would be surprised if with enough load development, you cannot find a suitable hunting bullet/load that will stay on an 8-10" kill zone at 500yds. assuming shot conditions and shooter ability allow it.

Ray, I'll go along with that.

Steve y, we don't mind shootin' the breeze here, hell it's something we can all hit believe it or not. I think I follow your logic and I'm not going to really like, you know, go ape or anything... Take a look at this idea, see if it makes sense.

I think that parallax and every thing else associatied with a rifle/load/sight/shooter IS related. What you referred to as "accuracy potential" is measured in terms of dispersion, an angular thing we call MOA. Take your rifle to the range and shoot a target 5 times(100 yards please). Next time at the range, shoot the same target 5 more times, and so forth until you have(hopefully) 25 holes in the paper. That represents how accurate < !--color-->the total system is, including errant primers, strikers, gnats, flyers, etc. ad nauseum...at 100 yards. It is a fair representation of the dispersion you may expect from day to day. Now, within the context of that parameter, how precise are you? How precisely can you wield your "dispersion"? Is is always evenly distributed around your point of aim, regardless of distance? Groups is groups, being able to dot the "I" is yet another tale, but one a bit extraneous to this specific discussion. None of the parts, pieces, or elements of the equation may be eliminated, they exist each and every time you pull the trigger. So now you're looking at an coyote, lasered at 487 yards...

So okay, the sear breaks(you here Hot Core?), the charge ignites, and the bullet goes...thataway. Those spare inches you mentioned...well they are not really "spare" and will be integeral to each shot, caused by random and uncontrollable variables. Such as, 1)Parallax. If your scope is not parallax free at the target distance, you have induced increased dispersion. 2) If you are holding the rifle a bit differently(you are in the field now), you have induced additional dispersion. 3) And so it goes for every element involved in the process.

The confounding aspect of most long range shooting is wind, perhaps more than anything else. Can't be avoided. Thing about wind is that is it rarely constant in either strength or vector, and it is NEVER the same from one moment to the next. It is not linear in effect but you probably know that, and the result compounds dispersion as range increases. The significance of this is that it is a dispersion MULTIPLIER. It makes mountains out of mole hills. If your rifle is truly a 1 MOA gun(see 25 holes), and you have a five MPH average wind factored into that, well, Great! Problem is, at your range the only crosswind your bullet sees starts at the 50 yard line due to a berm between your lane and another. Also, it only presents itself from the right quadrant due to local prevailing winds. Today, while your bullet heads "thataway" you get a 7 mph puff, full value from the left at the muzzle, then 125 yards of 10 mph, then a bit of this, a bit of that, and where the hell is "thataway" anyway? You get the idea I'm sure. All part of the deal...

It changes rifle to rifle for a myriad of reasons due in part to twist rates, both direction and magnitude. A bullet with very high Sg loses some of its precious BC due to yaw of repose and tractability issues, thus it is somewhat more influenced by wind. It also will have more magnitude in fast cycle precession(the one that nulls) due to ballistic imbalance, and thus another BC penalty. Conversely, while a bullet with lower Sg may not suffer these indignities so severely, it will have a larger magnitude of slow cycle precession and suffer ALL THE WAY TO TARGET for that. That precession does not null. Precessions are caused by imbalance on the longitudinal axis of the bullet, both fore and aft of the CG, and by cross winds, muzzle jump, muzzle blast etc. None of this is any more isolated from the accuracy equation than parallax, and even in a perfect lab tunnel some of it will still happen. The whole thing is so quirky that depending on direction of twist, a cross wind will cause a bullet to strike high or low, magnitude a function of Sg.

For these reasons and actually quite a few more, I don't think it realistic or advisable to try to isolate one component of the system and assign value "A" etc, etc.

And on a side note, I want you to know that I can be more long winded than you.

Good shootin'!

Dan