Posted: 11/6/2016 11:40:56 PM EDT
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I don't mean to arrogantly question village wisdom, but how much difference have you all found with variations in powder (ie; intentionally different amounts when doing load development) charge effecting precision? I see people do 3-shot groups for load development, or even 5 shot groups, but these are fairly statistically insignificant considering the amount of future rounds that are based upon that initial load development. Do people do/have 10 shot groupings at each load increment? I guess I'm trying to justify the process of going through 50 rounds on something that I'm skeptical of right now.
Sounds like people cite barrel harmonics as the logic behind this, and you're trying to get the bullet to the muzzle of the barrel at the peak/valley of the oscillation, and your barrel tip motion is near-zero so your (hopefully minor) powder variations have the least impact on precision/consistency? I'm guessing this varies from barrel to barrel (even within same geometries) because of rifling variations. Is that something you can actually chase within the realm of +/- 2gr of powder? ETA: Does the barrel even start to 'oscillate' before the bullet leaves the barrel? Slow-motion footage shows it not oscillating until afterwards... |
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If we are questioning village wisdom then...
I have never seen high speed footage of a barrel "whipping" until after the bullet leaves. There can be deviations in accuracy and/or precision based on the powder load though. Like it has already been said though, .1 grains is a good deviation to try and stick with. I have experimented with up to half grain loadings and still shot within an acceptable distance from a load that was different. For the record, I'm not a bench rest shooter. Their contribution to this thread would overturn my thoughts. They deal with minute measurements and their shot groups show that. I am looking for the most accuracy and precision I can get while still being practical. I shoot from prone, seated, bipod, tripod, monopod, trees, rocks and many other uncomfortable locations that would not be ideal for tiny groups. Same for Army snipers. Minute of man and all. |
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Sorry, I did not make that clear. I was mostly talking about when people are doing load development, and going by certain increments (ie; 40.0-44.0gr by 0.5gr increments), not capabilities to maintain consistency once you've supposedly found that amount of powder that "works great" for that particular rifle/barrel.
I'm just skeptical that one really needs to do the 'load development' if you are already maintaining consistency with your powder measurement quite well. |