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Anyone else have a rifle that shoots tighter groups at a distance.....say, 300 yards......than it does at 100 yards?? Some loads I run through my 7-STW will pile holes on holes at 100 yards and produce similar accuracy at longer ranges. But some loads will scarce go under 2-2 1/2 inches at 100 yards but will print the same sized group at 300 yards. The same loads are "deer accurate" to 600-700 yards. I'm wondering if there's some sort of stabilization phenomena going on that doesn't work itself out until a ways downrange or something?? Or maybe I'm just nuts. Founder....the OTPG | ||
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Yes, I have a Winchester M-70 Coyote in a 22-250. It struggles to get under one MOA @ 100yds. With 55gr. Rem.PL-HP but will consistantly put them in 1" to 1-1/4" at 200yds. With Hornady ya-da ya-da bullets it will print 1/2" @ 100 yds. but opens up to 1-1/2" to 2" @ 200yds. "The right to bear arms" insures your right to freedom, free speech, religion, your choice of doctors, etc. ....etc. ....etc.... -----------------------------------one trillion seconds = 31,709 years------------------- | |||
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I have a hunting rifle built by David Tooley that builds benchrest rifles. Several years ago he told me that on the fast 30's, he was building for 1000yd competition, would not stabilize the bullets at 100yds so he worked up all of his initial loads at 200yds. A couple of my 30-378's will group better at 200yds than at 100yds. | |||
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so, if i say "highly unlikely" does that make me a closed minded jerk? i don't believe it, but i could be convinced, i think ... opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
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I don't know you. So you could be a closed minded jerk. But not because of the "highly unlikely" comment.  I was just talking to my wife's uncle on this subject. He does more loading and shooting than I do. He's seen the same thing in his .338 RUM with some loads. Dunno?? Founder....the OTPG | |||
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While this has not happened to me, nor has my group size gotten smaller as range increased, but a Wimbleton cup winning friend of mine experienced something similiar in terms of MOA. Now mine you, his group size at long range was not inches less than close range, but the MOA was. He stated that a cartridge/bullet combination he was using actually tightened up after a couple of hundred yards. | |||
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This is what I was attempting to say. You got the wording down. The same load that's going 2 MOA at 100 yards is doing 3/4 MOA or so at 300 yards. Founder....the OTPG | |||
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I've heard the benchrest guys use the term "going to sleep" before in relation to the flight path of the bullet. I think the theory goes something like this: A rifle with a faster twist rate than is necessary to stabilize a particular bullet, which pretty much describes all hunting rifles, will tend to "overstabilize" a bullet. Think of a child's top as you first spin it, it'll precess around a certain spot while wobbling a bit before settlingdown to a steady state spin. The same thing happens to a bullet when fired, for the first X number of yards the bullet wobbles around it's flight path before settling down to a steady state flight. The bullet hasn't "gone to sleep" yet when it's precessing around it's flight path. Until the bullet has gone to sleep, it's deviation from the centerline of it's flight path is essentially random, at any given time it could be somewhere to the left, right, up or down from the centerline of it's flight path. If your bullet hasn't gone to sleep before 100 yds when you group it, your 1" group could be the result of 1/2" left deviation for one bullet and 1/2" right deviation for the next. However, say that the bullet goes to sleep at 150 yds, then it's no longer precessing or wobbling around it's flight path and the groups could actually tighten up as the precession is no longer happening. This is why the benchrest guys tend to use really slow twist rates compared to a sporting rifle. They want the bullet to go to sleep as soon as possible so they don't have to deal with the precession of the bullet. A sporting rifle is expected to shoot all weight/length bullets well so it's twist rate is designed to stabilize the heaviest/longest bullet that might be shot from that caliber, which is much more than needed for middle of the weight range bullet that will most likely be shot from that rifle. Assuming that this is a valid theory, then I can certainly see how a rifle could shoot tighter groups MOA wise at long range than at short range. | |||
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Interesting, simple and very plausible. It should (could?) stand to reason that switching to a heavier bullet may help this situation. I'm running 130 gr. SMK's in the STW. So they are pretty light-for-caliber. Maybe 150's or 160's would be less affected. Founder....the OTPG | |||
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jeffe Trust me it is true. I have seen it many times. A rifle shoots "usually under an inch" at 100, it shoots half inch at 300. A rifle that shoots around 3/4" at 100 yards, shoots two inches at 600. Also I have seen H&K 91's with Military 147gr Ball ammo that shoot a group the size of the palm of your hand at 100 yards.... that shoot a group the size of the palm of your hand at 400 yards. I have also seen guns that shoot under an inch at 100 that would not shoot under 6 inches at 300. DOUBLE RIFLE SHOOTERS SOCIETY | |||
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So does this mean that most sporting rifles will shoot best with heavier bullets? My Ruger 338 Win Mag shoots pretty well with most, but 250gn Nosler Accubonds and 250gn Woodleigh PPSN bullets are the two most accurate, and 300gn Woodleigh SNRN also shoot under 1 MOA. I generally only test groups at 100 yards though, because reading the wind is not one of my skills, and picking a windless day at the rifle range I attend is even harder. | |||
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338User You never know till you shoot at the "distance" in question. DOUBLE RIFLE SHOOTERS SOCIETY | |||
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Tony, It COULD be .. but i find the combo to be very limited and the opprotunity limited that it works .. what happens if you change bullets? I just don't know, but I am skeptical opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
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This sounds to me like more of a sight picture / target acquisition issue than a mechanical issue. I don't believe that the rifle is more mechanically inaccurate at shorter range; I do believe, for whatever reason, that one's sight picture can be more consistent at longer ranges, for certain targets. analog_peninsula ----------------------- It takes character to withstand the rigors of indolence. | |||
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So the overstabilized bullet is dancing around randomly at 100 but has to sleep in almost exactly the same path/place later on to make good groups further out? | |||
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Yes. Saw it once with boattails in .270 Wby and the analogy of seeing a football spiral "settle down" after at first being wobbly clicked with me. Rare, though... _______________________ | |||
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Sooo, error introduced between muzzle and 100yds will simply "self-correct" between 100 and whatever distance? If you mean that relative MOA accuracy will increase with increased range, I'll buy that under certain circumstances. But, 2 inches at 100 and then 1 inch at 300? Other than random anticdotal "evidence" (aka a sample size of "one" or maybe "two" at best). And then not accounting for probable shooter error (certain in ALL cases) variations in atmospheric conditions, pure luck and a host of other variables, just exactly how does that work out, math wise, physics wise, engineering wise? | |||
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I'm fine with that the bullet stops wobbling but in my head its impossible for groups improving with distance either MOA or inches. Imagine a hole in the wall to throw a ball through, then another hole in the next wall sized so that you also see some of the wall around the hole in the second wall through the hole in the first wall (less MOA and, no I'm not a pedagogy expert). Then imagine that all the balls you throw through hole one also should be hitting hole two (forget gravity for a second). If you use all your skill to hit the first hole then you'll need luck as well to hit the second one. | |||
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Yep. Several theories about why but I don't think anyone can prove or disprove any of them. Many BR matches are shot at both 100 and 200 yards. Few shooters use the same load at both distances because of exactly that effect. | |||
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Nah, your previous posts convinced all of of that years ago.  ----- For those of you who keep the majority of your shots inside 100-200yds, it would be difficult to convince you that it is a common event. You can either rely on those who know better that it does happen, or remain blissfully unaware. The wider groups up close are created because the Center-of-Mass within the Bullet is not exactly in line with the CenterLine of the Bullet. Therefore it takes awhile for the Bullet to stabilize the spinning around the Center-of-Mass, since it was forced to spin around the CenterLine of the Bullet by the Bore. Good Hunting and clean 1-shot Kills. | |||
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It is a genuine occurance, and not all that rare either, where accuracy increases (MOA-wise) as distance of flight increases, for spinning projectiles from some rifles or loads. I've seen several sound scientific explanations of causes, but I haven't bothered to memorize any of them. Just knowing there are sound reasons and documented valid and reliable tests is enough for me. That way I don't need to doubt my own tests when it occurs with my rifles or loads, and I don't waste a lot of time re-running my tests. I don't need to know the detailed contributors to, and math of, WHY it happens. I just accept it and go on with my experiments. Belief that things MUST happen a certain way, produce a certain result, and can't be valid if they don't match my theories doesn't contribute anything positive to my tests...such set, immutable, beliefs just get in the way of my recognizing reality when I see it. | |||
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Another thought. On the 7mm I find that Boat tail bullets take 200 yards to settle down. Since my hunting is done from 50 to 400 yards. I find flat base bullets work best. They settle down right away. I know that the 160gr FB Barnes are killers to 500 yards. I'm good with that. Now a 175grBT is a different animal. Those suckers are dead on no matter what the range. My hunting rifles are just that. If I can hit the vitals on my game, I don't care about group size. I don't bring a bench into the field, so I don't shoot them that way unless I am developing a load or zeroing a scope. If your max shot is 200 yards in your area, who cares what happens after that! I have dedicated "brush" guns, heavy bullet short range hunters, I also have 700 yard rifles. Each rifle in between has a specific purpose. Different bullet styles, contours, powders, loads, all effect the outcome. The "sleep" concept is like a corkscrew. The back of the bullet is spinning in a larger axis then the nose is. As the bullet stablizes they are turning on the same axis. Because the bullet weight, velocity and rate of twist are the same, the outcome is the same, every shot. | |||
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Virtually all the long range rifles I build have a tighter MOA at 200 or 300 yds. than at 100. If you ever have the opportunity to fire a tracer up into the night sky you will see it spiral until it stablizes. It does this around it's line of flight. The spiral gets smaller until it is steady on the line of flight. In my experience a fast twist and heavy for caliber bullets seem to do more of this, especially in the larger calibers, 6.5 and up. I just built a .220 Swift with a 1-8 twist that shoots 3/4' group at 100 and 1 1/2" group at 300 and 400 with 80 gr. A-max.....Tom SCI lifer NRA Patron DRSS DSC | |||
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i have witnessed this with my 6.5x.270. it has two loads that work good at different distances, MOA wise. the 100 yrd load will not group at 200 yrds and the load that will only group average at 100 will group way better at 200. i assume much of this depends on my own capabilities, but on a good day it is esily evident. i discovered this when i talked to the guy that built my gun about what bullet he recomended i start out with. he recommended the 129gr. hornady bt. i tried it and wasn't real impressed with it at 100 yrds. he asked if i tried it at 200, i did and it shot great there. trapper2's explaination is exactly what i learned causes the phenomena. the bullet actually orbits around the intended path of flight untill a "sweetspot" in the dynamics between spin/length/weight/velocity/conditions is reached where it, as the bench guys say, "goes to sleep" i also remeber something about it showing up more often with boatails vrs. flatbased bullets. this may be because generally a boat tail has it's CG more centerally placed along it's length so the bias of dynamics between polar moments is more uni-directional. | |||
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I'm turning into a believer. I was only half convinced of the opposite to begin with based on prior experience with my quick judgement vs. experience. If the map and terrain disagree, the map's still right. | |||
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Back when I played with BPCS, many of the guys who were better than me said that their rifles were more accurate at the longer ranges. As I recall, some of them used 2 different bullets in their rifles - one was for the 200 meter chickens and another for the pigs, turkeys & rams. The "theory" (?) behind it was that a bullet went to sleep at the greater distance. I personally was never good enough to see this phenomenom but coming from more than one of the best guys in the sport, I have to believe it. I know, it seems to go against logic. Bear in Fairbanks Unless you're the lead dog, the scenery never changes. I never thought that I'd live to see a President worse than Jimmy Carter. Well, I have. Gun control means using two hands. | |||
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Could it be due to scope paralax? I believe most scopes are set to be paralax free at 200 yards or so, which means you might get some paralax at shorter ranges. This could make groups open up at shorter ranges if your cheak-weald isn't exactly the same for each shot. Just a thought. | |||
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It is certainly very uncommon for a 1 in. 100 yard rifle to be 2 in. at 200 and 3 at 300. I don't think I have one that will group better at 300 than 100, but I have several that will shoot virtually the same at 100 and 200, as well as some loads that will shoot .5 MOA at 100 and shoot 1.5 MOA at 200 and these are not scope related. Change loads with the same rifle and scope and the results are different. A shot not taken is always a miss | |||
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So basically what is being said here is that a improper bullet is being used or an improper twist or somebody is trying to overdrive a bullet that has to slow down to a reasonable speed before it stablelizes. Makes sense to me. | |||
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j stevens, what we're talking about is the phenomena of a gun/load/bullet that won't group decently at 100, but will at 200 or 300. by purely mechanical laws ( no out side influence such as winds, paralax,etc.) a group of any size should continue it's deviation from origin and spread proportionaly larger as distance increases, such as your example of a .5 group at 100 and 1.5 at 200. that behaviour is more or less normal and expected. sometimes the opposite happens...thus the subject matter. if you have a gun that will shoot virtually the same phyiscal size group at both distances, this subject matter is actually happening to that gun. again, by purely mechanical rules (minute of angle) your group has to be larger as the distance increase. | |||
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merlinron The problems lies in that when the bullet leaves the barrel, a whole lot of things are happening which we have no control over, possibly don't even understand. I would say that a rifle that groups in a linear manner as distance increases is the exception, not the rule. There are many good 100 yard loads that shoot 2 MOA at 300, etc. A shot not taken is always a miss | |||
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This is my problem with the theory of improved accuracy at longer ranges. I think it is something else like the scope, rest or the guy behind the trigger. | |||
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i gues we're saying the same thing as far as what we think as the rule. that said, if it demonstrares a linear tendancy, then the phenomena is happening, as it should continue to spread it's group in a proportial dispersion as distance increases....ie,(roughly speaking) 1" at 100...2" at 200...3" at 300 and so on, essentially a "1 minute of angle group". a reduction of this proportional dispersion would mean that it is shooting more accurately as distance increases. is this" minute of angle group",as i explained, what you refer to as "a linear manner"?... i consider a "linear manner" to mean somewhat parrallel , 1"( 1 minute) at 100 and less than 2"(less than 1 minute) at 200, etc. if so, then we are more or less in agreement and please excuse my post!. | |||
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j.zola, the bullet doesn't "self correct", but it can follow closer to it's intended line of true trajectory as it goes to sleep. as it reaches it's sweetspot and the orbit and jyration settles down it will change it's random corse to one more closely parrallel to the intended line of flight. the sooner it does this the less deviation from that line of flight it will display...tighter group. i believe that the bench guys use/choose a rate of twist that promotes this settling at a point well before the target distance by adjusting velocity untill they find the sweet spot. the assumption is that by a really tight group, the sweet spot is being reached very early in the flight and random deviant flight is eliminated before it gets too large, opening up the group. i would assume that beyond shooting when wind is down in all aspects, not much can be done beyond the mechanical aspects of getting bullets to follow each other. in archery this same phenomina of a bow shooting better at distance is the accepted rule if set up good. arrows do exactly the same thing and can be tuned to setlle thier paralax out as soon as posible so that the violent random flight is eliminated as soon as possible to minumize deviation from intended path. the difference is that an archers projectile is indeed tunable to hit a sweetspot at a predetermined distance where as a bullet is not. tht's whay good target arrows cost 3-400 bucks a dozen. | |||
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