- Thread starter danatkins
- Start date
That’s because velocity flat spots are a myth. Run your OCW based on group size not an imaginary velocity flat spot.
Or, just pick a charge weight based on desired velocity and tune group size using seating depth.
Or, just pick a charge weight based on desired velocity and tune group size using seating depth.
Except you have a giant “flat spot” between 41.9 and 42.3
Any variation you see there could be the fact that you’re only shooting 1 shot per charge weight. This is also an extremely common charge weight range that many people settle on, so no surprise there.
That said. I’m also in the pick a velocity and tune seating depth crowd. And when it comes to 6.5 creedmoor, I usually shoot the same load through all my rifles with enough success to not worry about developing a load for each one. AKA, just pick one and get to shooting.
@danatkins do you think every round of a given powder charge weight exits your muzzle at exactly the same velocity?
They don’t. There’s variation around the mean. The more rounds you fire at a given charge weight the more likely you are to find the true mean and the true variance around the mean.
Conversely, the fewer rounds you shoot at a given charge weight the less likely you are to find the true mean and the true variance around the mean.
That’s why shooting a single round or even three rounds per charge weight often shows a “flat spot”, which is just a fragment of normal variation.
Shoot even 5 rounds and the likelihood of seeing a flat spot disappears.
They don’t. There’s variation around the mean. The more rounds you fire at a given charge weight the more likely you are to find the true mean and the true variance around the mean.
Conversely, the fewer rounds you shoot at a given charge weight the less likely you are to find the true mean and the true variance around the mean.
That’s why shooting a single round or even three rounds per charge weight often shows a “flat spot”, which is just a fragment of normal variation.
Shoot even 5 rounds and the likelihood of seeing a flat spot disappears.
So instead of taking everyone’s advice, you’re also going to ignore your own desires (there is a clear flat spot between 41.9 and 42.3). What was the point of even posting?
He absolutely doesn’t know anything about “flat spots.” You can have a big name and mean well and be absolutely and completely wrong.
Do a velocity flat spot ladder test 10 times. You won’t get 10 consistent “flat spots.” If you do, and it continues to be consistent, researchers at MIT and Applied Ballistics would welcome this revolutionary data.
Flat spots are a function of the testing and random errors associated with loading. Looking for them is a little like snipe hunting. Elusive.
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