fredo -
Over a chronograph, at different atmospheric conditions (as your saying) is good way to finding sensitivity in powders, but it is not the only way of course. Myself I've even ran sensitivity tests using warmers and coolers to heat/cool ammo to extremes for tests (have shared a couple of them here on accurateshooter in past years).
Another way is to just go shoot (field test) in different conditions, at different times of the day and different days. Which is what Matt did, plain and simple, and reported his findings in his reply above. Just because he did not do it to the standards you think he should have, doesn't discredit his input at all. Especially from repeatedly hitting the mark at an extended distance of 1370-yards.
Unless you think 1370 is just some "chip shot", I can't see how you don't find Matt's input to have significance, just as he reported it.
By the way, Matt has been winning and breaking 1000-BR records for well over a decade.
He is one of the most accomplished shooters in the sport.
My 2-Cents
Donovan
Thanks for the reply, sir.
The insignificance comes from a lack of accounting for variables that can & do affect bullet flight. And especially so, at 1350+ yds. Nothing more, nothing less...
Also, doesn't rifle's "tune" have something to do with POI shift at distance, as well? Isn't that yet another factor that could affect observed results, beyond the proven & measurable affects of environmental conditions?
Not discrediting anyone who can shoot tiny groups at long range, but I'm more concerned about & interested in, hitting the target...with the first shot. And doing it with a shoulder fired weapon from an impromptu field position, under otherwise unknown conditions, at that...
Without having atmospheric data to input & account for, trying to make a 1st round hit much past 800yds can be an exercise in chasing one's tail. At 1370yds, I wouldn't dream of ignoring atmospherics and having a realistic chance of actually making a first round hit on an appropriately small target. Simply because, air temp, pressure and wind have enough affect on bullet flight at that distance so as to make it a fool's errand to even try...
That may very well be where the difference in opinion is stemming from. I can see how a shooter can get by with ignoring atmospherics when 'sighters' are allowed on a huge target, and being allowed the opportunity to "walk in" POI to a desired center point, prior to shooting for score. In effect, that would be accounting for atmospherics by trial & error, vs. cutting to the chase, measuring & solving for them...
Unfortunately, the luxury of 'sighters' is not afforded a field shooter, hence the need to account for every possible variable to actually hit the chosen target...with the first shot. Different game, different rules & allowances...
That all said, when I "prove" a load, I will shoot it at a varying temps over the Magnetospeed & note and record °F/fps variability of said load in my ballistic program. I've measured sensitivity little as 0.1, and as much as 0.9 °F/fps for given powders. With that information "proven" via an actual measuring device, that is another data point which can be input into ballistic solver. That temp. sensitivity data point input allows the ballistic solver to automatically adjust MV when solving for corrections under current temperature...
Again, this stuff is essential to making a hit on target the first time, a different game than shooting repeatable groups in a BR setting.
I can learn & appreciate the attention to detail that BR shooter go thru to make as "perfect" ammo as possible, and I've learned much from those efforts! Case & bullet sorting, weighing cases, turning necks, etc... I incorporate all that shared & accepted knowledge into my efforts, doing all the same prep as a BR shooter does to make "perfect" rounds to send downrange.
What I'm not seeing, is how someone with the same mentality to strive for "perfection" & attention to the smallest detail, would so easily ignore/dismiss the external (atmospheric) variables that have a very tangible & measurable affect on the flight of their meticulously developed ammo?
Just don't make no sense to me, so I'll chalk it up to it being the different game we play.
Thanks for the thoughts. The path toward knowledge is in the ability to acknowledge & potentially accept a viewpoint that otherwise may not have been considered. That's really the reason for discussing this kinda stuff, don'tcha think???
Good shooting & take care!
