Reply To: Why is it that round lead ball ammo generally performs poorly in AGs?

Forums Pellets, Projectiles, Slugs, & Ammo Why is it that round lead ball ammo generally performs poorly in AGs? Reply To: Why is it that round lead ball ammo generally performs poorly in AGs?

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I_Like_Irons
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“ztirffritz”I often wondered why round balls weren’t made with dimples, like a golf ball.  It is supposed to stabilize the ball in flight and help it travel faster and farther. 


The golf ball spins 90 degrees to the way a bullet spins.  The dimples do two things: they first give a bit of bite to the air which further reduces the air pressure along the top side, and second they create vorticies which reduce the skin drag effects. 

However, I played with this idea using both round balls and Crosman Premier Heavies.  I used 60 grit glass bead blasting media.  I glued a thin layer of media onto a flat piece of steel.  I rolled a sample (30) of round balls, and the noses of CPHs  on the plate until there was an even dimpling. 

I found, though, with the round balls and the CPHs there was a slight increase in drag.  I shot samples with chronograph screens at 2 and 27 yards with untreated and treated projectiles.  The 2 yard screens showed no significant velocity difference, however the treated projectiles showed slightly lower velocities at 27 yards.  The other thing that happened was there was more spin drift noticed at the 30 yard target.  Groups were larger as well.

Unfortunately, dimples on projectiles rotating about their axis of travel, do not seem to reduce drag, and do not seem to increase the accuracy/precision.  The evidence by this one trial seems to indicate the opposite to be the case.