147 grn bullet "softer" in 9mm than lighter ones?

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BrokenWheel

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I noticed when going from a 115 grain bullet to a 124 grain bullet, there was less muzzle jump and generally less felt recoil - at least thats what I felt. I figured it was because the heavier bullet was moving more slowly causing the reduced recoil sensation. A load for a 147 grain would theoretically be moving even slower (subsonic?) do you think the recoil, muzzle rise would even be lessened even more than in 124grain bullet?
 
I think so, I have shot 135, 145, and 147 grain 9mms for IDPA and find them more comfortable to shoot even if the power factor is the same as for a lighter, faster bullet.
Some say it makes the gun feel "sluggish", though.
 
weight and velocity = recoil

a easy way to measure is multiply the weight by the muzzle velocity.... the higher the result the more recoil.
 
My theory:

147gr bullets on top of small charges of fast powder recoil less than lighter bullets on top of heavier charges of slower powder, though both loads generate the same momentum. It has to do with the pressure curve: a light charge of fast powder expands it's energy sooner and slows down the rate of acceleration of the bullet in the barrel. The slide responds in kind and the recoil sensation seems soft. A light bullet on top of a heavier charge of a slower powder feels more energetic because the powder charge expands it's energy over a longer amount of time. The bullet/slide accelerate harder due to the additional energy from the additional powder.

Even with the same bullet weight, recoil can differ based on the choice of powder. For example, 3.3 grains of N320 recoils way softer than 3.6 grains of 231 under a 147gr bullet, even though both loads have similar velocities.
 
147s seem to shoot the softest in factory ammo. In light target loads the 147s are very soft because you can get them to cycle the gun at very low velocities.
Less powder is used in both cases than with 115s, reducing muzzle blast as well.
 
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