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Old August 1, 2021, 04:06 PM   #9
Join Date: March 4, 2005
Location: Ohio
Posts: 19,987
Originally Posted by cavediver27
I ran them all through my chronograph and found no spiked velocities or evidence of over pressures.
Just to be clear, a chronograph doesn't measure pressure. Matching velocity (actually, matching muzzle energy, but the two coincide) proves the average force due to pressure on the bullet over its whole trip down the barrel (less that needed to overcome friction) was the same, so average pressure was the same. But it doesn't tell you what the peak and muzzle pressure values that made up most of that average pressure were.

Nonetheless, as long as you are using the same charge of the same powder, it is unlikely the same average velocity would be produced if the peak wasn't averaging very close to the same value. There are some odd situations where it could happen, but they are mostly applicable to rifles shooting bullets too light for the burn rate of the powder used with them. I am just posting this detail so that someone reading the thread doesn't take the notion into their head that they can get peak pressure values directly from chronograph readings regardless of powder type. The relationship between peak pressure and velocity varies by powder, sometimes quite a bit.
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