Thread: Hornady sub-x 175gr load data...

Meh, in supersonic loads yes I'd agree but in this case we are setting the powder amount to control velocity. All other things being equal, it's not the weight of the projectile but the bearing length causing friction in the bore which gives the powder requirement in this case. So for a shorter projectile, less bearing length, less friction, less powder - the listed loads seem to be the opposite for the similar velocity in this case. I can't find any real-world loads to cross check that but it seems wrong to me... Starting at 12.5gr might end up with a wildly supersonic load so what I'm wondering is if Hornady has listed the 'max load-work down' but a subsonic velocity or something else is not kosher.

Info for the Speer round nose 180gr pill is generally noted at 10-10.5gr TB across the web from what I've seen for about 1040FPS depending on barrel, so where I'm getting a little confused/curious is why the maker of the 175gr Sub-X pill is stating 12.7 for 20FPS more than what would be considered normal a relatively similar pill, and then 2.2gr more than a heavier similar design pill from the same brand for only the same 20FPS more speed. It seems like an anamoly to me, and where my thinking is with this is trying 10gr as a start point, testing for stability and velocity and going from there - risk being a bore lodge. The 151gr cast 'Tokoroa special' load is about 8.5gr TB, so 2gr more for the 175gr Sub-X kind of fits the rule of thumb above.