Gary,
So it sounds like using a 1000 yard control for measuring ES and SD merit might be less than ideal as the control has numerous significant variables to be useful. Like, the wind, doping for the wind and the rest of the errors that follow, trigger control, breathing, sight picture, etc. These errors induced by shooter have realistically more bearing on bullet flight than velocity, especially if many occur at same time.
Would you agree that using the virtual worst case control for my analysis would not be as reliable as a control that had fewer variables? After all, Im looking for a control, a standard to base conclusions on.
The data you have offered is definitely worthy. This helps me understand how ES and SD getting smaller may not have a proportional effect on group size, or ANY effect. This is a start for me to change my understanding of velocity ES merit.
May I ask if each shot fired was immediately correlated to the velocity data and mapped on the target? Rather than look a a bulk attribute, I believe any testing must be done shot by shot and correlation of shot data and impact point must be completed. After all, we are not really looking at ES as a CHUNK, we are using ES to offer a generic number that represents a multitude of single examples. It would stink to have to rummage thru 1000 shots worth of velocities when we can isolate a cluster and make an average from the cluster. But the impact each individual shot and its deviation from normal or anticipated performance is LOST COMPLETELY in the SEA OF DATA the ES number represents. Thats why medical folks study GROUPS or people, but take samples from INDIVIDUALS and document them very accurately. GROUPS are easy to make statistics from, difficult to analyze accurately. They are an AVERAGE, non-specific. You cant fix a group of sick people at once, you must attack the disease on an individual basis. Then the group GETS HEALED.
Does anyone have “Shorter” distance data avail? Forgive my lack of experience and potential for speaking out of turn- I “understand” (not having ever shot 1000 yards) it is less the load and more the shooters ability to contend with the extreme environment presented at that distance, that make major achievements like Garys possible. Is that true? Of course a reliable load would be needed for any achievement at that distance, period. Gary must have had a very solid load to work with from the get go.
Would you agree Gary that at 1000 yards, the velocity data or velocity error could have as much group size influence as your ability to accurately dope the shot, hold and read other conditions? Or vice versa? Considering it only takes a few thousanths of an inch at the muzzle to steer a bullet inches in an unintended flight path (over 1000 yards), could the group enlargement, or lack thereof be the product of several introduced errors, including but not limited to the velocity changes from shot to shot?
Id like to put this to test, but if I use a load value that is very very accurate, by throttling powder charge to create velocity changes will ultimately alter the real accuracy stats enough to where too many changes occur from that one reduction or increase. Just about any variable changed will alter the entire test. Cant just change one value to make velocity go up and down and expect the cartridge to perform otherwise as expected. The bullets dont have internal brakes either to slow them down a bit. This is tough. I suppose I could try to verify a load with a broad “sweet spot", one that over a grain change up or down typically doesnt reduce overall group size. I see the issue is as follows: If I pull a shot, I have to isolate that round, throw the data out. If I hold wrong or have a bad sight picture at let off, then again, throw out the shot.
It seems that a completely BLIND test would be required and I would need to have the velocity changes happen- NATURALLY and w/o force. Life will just have to happen. Basically to prove or disprove, a spotter would be necessary with a blind study. Shooter shoots the best day of his life at 100 or 200 yards with a reactive load. One that does indeed respond at least 40-50 fps with a grain or less change in powder charge. Spotter has to plot each round and each round on paper gets labeled with its corresponding velocity. Basically a cartridge that will react in velocity changes proportionately to powder volume change and with a great deal of sensitivity.
The problem is I have done this same operation only not specifically as a study, just going to the range to prove handloads. My kids make great spotters and they are super kids! They get bored with shooting at the range though, rather play with an Ipod or a guitar than continue endlessly to burn ammo on non-reactive paper targets. I don't blame them either. But dad forces them to stay involved, sometimes. Spotting and calling shots. I expect from several rifles I own, groups under .25 inch at 100 yards, namely my 22-250 Savage. I expect at 4200fps, my 50gr flat bottom bullet to cut, even in the rain and a nice breeze, at 100 yards, a single pencil hole. Unfortunately it only does this with cheap Midway Dogtown or Nosler Blems- jacketed bullet under massive pressures. It shoots like this when its hot, cold and even when handed to another shooter who has never fired the thing. It just shoots really well, all the time. As long as I feed it with ultra massaged brass, large quantities of Varget, etc. I will cry when my Savage burns thru this barrel.
SOMETIMES- this is done over the chrono and I can call “good shot” five times or ten times in a row, for several hours. My kids can produce data for me which IS proportional to velocities changes. My kids can say DAD your a 1/4 inch high on that one. I can take the 10 lb rifle and commit, good shot and I DIDNT DO IT!!.....look at the chrono and see a 35 fps jump for that round! I will admit, there are strings that are sub 2 digit ES and I cant read CRAP. Its one hole OR I pulled, read wind wrong (So Cal mountain ranges usually are gusting daily after 10 AM from 6-20 MPH), ETC. Some folks say one hole group. One ragged Hole. That is not what Im saying. Im saying poke one bullet thru paper, then walk away because that the total size of the opening. One diameter of the projectile (well I exaggerate, its bigger than one diameter but not much). I cant explain why its bigger than one hole even when the ES is at 4-7 fps, but it is. Im human, the rifle is imperfect too, etc, etc. But I clearly believe if I hold well enough and hand load as well as I have been able to, there should only be one hole! I digress.....
BTW: The load was not found over a chrono. The Chrono confirms the group size. It was a basic load workup from Hodgdon data. Gary, call it a ladder or what have you. 10 rounds at .2 gr increase till I found a pinhole. Then work brass into oblivion with tools and refine said pinhole. Then verify said pinhole with Chrono. Zero vertical dispersion and an ES below 10, seem to correlate well. I digress again.
Add a few more rounds in the sub 15 fps ES range and they all stack. Pick one out of the block that has very little neck tension (I can move the bullet up and down due to neck sizing and extreme neck thinning), I shoot, chrono says 30 fps SLOW (below the mean velocity) and my kids says, dad your .25 low! I cant see the chrono when I shoot. I cant predict a light charge before I pull the trigger or a loose neck. I dont have ESP so that I unintentionally vary my hold to follow what the Chrono will output in the future. Basically I expect ONE TINY HOLE in the paper. And IF a hole appears ABOVE the ONE HOLE or BELOW, I can directly correlate that shift in impact point with a velocity change.
This is WHY I believe ES is as important as mentioned elsewhere previously. Now with that said- MY EXAMPLE IS NOT as an extreme condition as using 10 shots that you cant correlate at 200 yards (as indicated by others in other threads) nor 10 shots at 1000 yards that again, are not placement correlated with velocity data. It is as Scientific as one can be with propellants that react to environmental changes and user input. I dont have a machine rest. Holding on a target that I can see fibers of paper on thru optics, its actually pretty easy to confirm that a shot wasnt pulled. Ive not performed this test just once or on one string, this is what has occurred a multitude of times with both handgun (scoped) and rifles. Even with cast bullets (when a gun will shoot them well enough to be viable). The trend seems to be consistent. I have found groups that are large, I cant read crap into it. Like reading tea leaves in the bottom of the cup. But who cares at that point, its a shotgun blast. I have a shotgun for that type of accuracy.
Note I have not mentioned shooting cast bullets with an average group size of 3 inches at any range. The control for my testing is basically a Stanford Single Hole Punch on my office desk. If there is a change, i'd better figure out why and it becomes pretty easy, me or the ammo! The chronograph is one indicator of error. Low or high ES cant make me pull a shot 2 inches left! Common sense is a very good indicator too. Chrono can tell me why I went high, more often than not, due to velocity change. Which is quantified in the ES number.
Lastly, I have not at all indicated that other factors that are far more critical dont open my groups, like me jerking the trigger, flinching, glare, fatigue, COFFEE, excitement---- My groups open for all sorts of reasons that are not attributed to Vel ES. But I firmly believe that if there is a velocity increase and I see the shot placement higher than average, and the inverse as well, low/low..... Indeed A LOW Extreme Spread in velocity does contribute to smaller group size (well hell, Id better say this right--- A SMALLER VERTICAL DISPERSION). But it wont IN AND OF ITSELF make a small group, only a human can do that.
