Hodgdon Subsonic Load Data
We have a question for the community. Hodgdon has recently published subsonic load data: https://hodgdonpowderco.com/wp-content/uploads/2023/04/subsonic-data-final-1.pdf
The list contains the following load data: .308 Win, 190 GR Hornady Sub-X, 2.69 C.O.L.: 2.690'' - 13 GR H322 Hodgdon
The bullet is 1.3'' long. Seated depth is then 0.63''. The empty case capacity is 56 GoW, the powder bulk density is 55.8 lbs/ft3.
So the fill rate (volume taken by powder in the cartridge) for this suggested load is around 33%. Only one third of the available cartridge is taken by the powder.
HOW CAN SUCH A LOAD ENSURE CONSISTENT IGNITION BY THE PRIMER? Has someone tested this load? Any feedback in general at what minimum fill rates you start to get problems /nervous?
I used this load data this weekend out of a ruger bolt gun only made up 10 rds for trial and didn’t use any filler and all 10 fired and velocities were around 1050fps out of a 20 in barrel