Here’s how I do it!
GIVEN - Every barrel on any type of firearm or firelock - using ANY type of propellant or powdah - vibrate like a tuning fork when shot and the barrel whips in a sine wave manner, typically vibrating up & down like a looooong sideways 'S'.
A node is where the barrel is at the point(s) of the LEAST movement. That is when you want your shot to be fired. There may be several nodes identified as you increase your powder charge. To test this, you ‘randomly’ shoot 3-shot groups at a bullseye for each charge, beginning with your starting load and say working up in 5-grain increments for a few different charges. Repeat with other sets, up to what you think may be near your max charge, say if you wanted to identify a lower co$t or more accurate target load, as well as a heavier hunting load.
Note - One does NOT shoot all of one charge at once, but shoot them in a random pattern, as then 'statistically' you will have normalized the data by eliminating YOUR bias and spreading any human-induced variation across ALL of the shots and groups.
Examples of such bias are your aim/hold, light on the target, cheek and/or shoulder position or pressure, yanking the trigger or like when you begin to shoot poorly towards the end when tired. Any such factor - independent of the load - could adversely influence or bias the last group's results. Statistically shooting them in a round-robin manner thus significantly increases the confidence you can place in the results. For consistency, I pre-load the charges in plastic tubes marked with the charge weight.
Those shots with the tightest group denote the range around a node. To fine tune, then experiment around the identified node, if you care to. I also do similar for my modern unmentionable 1,000-yard rifle, but this method (based on physics) also works for black powdah as I have proven it many times. Believe or not, but I get many PMs saying one can’t apply ‘modern theory’ to black powder shootin’!
The summary here is … that in as little as 12-shots I determined what load this 48” barreled ‘Rob Miller’ Carolina 62-cal flint smoothbore likes!
GIVEN - Every barrel on any type of firearm or firelock - using ANY type of propellant or powdah - vibrate like a tuning fork when shot and the barrel whips in a sine wave manner, typically vibrating up & down like a looooong sideways 'S'.
A node is where the barrel is at the point(s) of the LEAST movement. That is when you want your shot to be fired. There may be several nodes identified as you increase your powder charge. To test this, you ‘randomly’ shoot 3-shot groups at a bullseye for each charge, beginning with your starting load and say working up in 5-grain increments for a few different charges. Repeat with other sets, up to what you think may be near your max charge, say if you wanted to identify a lower co$t or more accurate target load, as well as a heavier hunting load.
Note - One does NOT shoot all of one charge at once, but shoot them in a random pattern, as then 'statistically' you will have normalized the data by eliminating YOUR bias and spreading any human-induced variation across ALL of the shots and groups.
Examples of such bias are your aim/hold, light on the target, cheek and/or shoulder position or pressure, yanking the trigger or like when you begin to shoot poorly towards the end when tired. Any such factor - independent of the load - could adversely influence or bias the last group's results. Statistically shooting them in a round-robin manner thus significantly increases the confidence you can place in the results. For consistency, I pre-load the charges in plastic tubes marked with the charge weight.
Those shots with the tightest group denote the range around a node. To fine tune, then experiment around the identified node, if you care to. I also do similar for my modern unmentionable 1,000-yard rifle, but this method (based on physics) also works for black powdah as I have proven it many times. Believe or not, but I get many PMs saying one can’t apply ‘modern theory’ to black powder shootin’!
The summary here is … that in as little as 12-shots I determined what load this 48” barreled ‘Rob Miller’ Carolina 62-cal flint smoothbore likes!
. I agree with your reasons for the assertion and think that all of it will likely effect accuracy but that's only a theory without being proofed by testing. 
I've had occasion to watch BPCR shooters at my club. Regular monthly matches are held there and there have been quite a few high level competitions run there. Every single shooter has always rested their barrel on the cross sticks right at the Muzzle. As close to the Muzzle as possible. Nothing to do with nodes, it's all about minimizing the effects of any movement of the rifle and shooter .
