Finally I got around to writing up my load development and testing (actually done in September).
I shot the 150 loads during my lunch breaks at work - where they performed perfectly satisfactorily on the rifle targets (6" squares of wood and roughly 2"x6" lumps of old fence post at apprx 30 yards). Which of course told me very little!
I chose some 180 grain bullets (.311 "303" Sierra Pro Hunters) and Using Hornady's IX edn' as a guide, chose H380 powder which it listed with
much higher charge weights than the Hogden website.
I loaded 4 rounds in .5 grain increments from 48.5 to 52.5 grains. The brass is PPU once fired, FL resized and trimmed to factory length, and the primers are the ubiquitous CCI200 LR. I started and finished my range session with 3 rounds of factory PPU 150 grain soft points (to act as a sort of control, as well as to free up some more brass for reloading)








The groupings are pretty bad - all I'll say for myself is that I am unused to shooting freehand over open sights with an old RH bolt action. At 49.5 I think I pulled a shot rather badly (either that, or through sheer fluke put a bullet through an extant hole, but I think that's unlikely). At 52 grains I got a pierced primer and stopped (hence only two holes, and no 52.5 target).
The best group were somewhere between 51 and 51.5 - but when I looked over the 51.5 cases again, some of them pretty badly cratered primers (not pierced though) so I've stuck with 51 grains. I did see some people online suggesting that I might use magnum primers with the H380 powder, but I'm not sure. Would be great to have a chronograph too, I'd love to know how fast these bullets are traveling.
I'm not 100% happy with the results. I'm happy that the loads I've made would kill a deer - but I'm looking to start again later in the year with a stick powder in the IMR-4350 range.....