Images taken with a high speed flash system based on the Mumford Time Machine to observe the rifling on a lead pellet fired from an air rifle.
The rifle is a Daystate Mk4 kindly modified by Daystate to give me a large level of control over the pellet velocity. The pellets are 0.177 Air Arms Diabolo Field.
The flashgun is being triggered by an IR beam across the muzzle of the rifle.
The following image is a crop from the previous photograph showing the rifling marks left on the pellet
These images are taken after a pellet was retrieved and shows the rifling on the pellet skirt and dome
Power and Pellet Deformation
The following image is of two pellets fired at differing power levels and velocities.
The left hand pellet was shot at 85 fps and the right hand pellet was at 780 fps.
The depth of the rifling has been significantly increased on the right hand pellet due to the skirt being expanded further into the barrel rifling. There is also a hint of deformation in the flat side of the skirt due to the increase in power or from the landing impact? In order to take the second shot at full power and retrieve an undamaged pellet I was shooting at a fluffy cushion over 250 yards away, eventually I managed to land a pellet on it it would of been a lot easier with ballistic gel. My thanks goes to a friend who was prepared to trudge up and down the field to check if I’d hit it because I didn’t have a clue!