Anything specific for these HST rounds.
These were an LE overrun and got lucky. Got 124 and 147 grain bullets
Also got 147 HST from American Reloading. Yes, there were a few odd 124s, but not enough to work up a recipe.
The projectiles arrive covered in sticky tar sealant and grit. I used acetone and a
gentle manual tumble in a glass jar to clean it off.
The pull-mark has a burr on it - some are worse than others. It can cause the round to not fully insert into a case gauge. (Spent a few days with a Sharpie to find that one.) If the round doesn't fit into the gauge, I carefully use a very fine file to remove the pull-mark burr, then burnish with a wire wheel. Sounds fiddly, but I wouldn't want the burr hanging up on the chamber lip and compress the round while it chambers - that's a possible KB.
I fired commercial HST (P9HST2) over a chrony and got 1100fps with my 4.5" KKM barrel. I use Blue Dot under the 147 HST. 1.125" OAL, no crimp. VERY consistent and accurate.
Initially tried CFE-Pistol, but hit Hodgdon's upper limit. Research (thehighroad, IIRC) indicated that a slower powder is appropriate for slow-launch 147s. LGS had Blue Dot. BE-86 is also reported to be a good choice.
The 124 HSTs have one cannelure. The 147 HST is a longer round, and has two cannelures. Makes it easy to visually sort. I also weigh each projectile - some 147s are a little too light to be considered 147.
Edit: the OAL of 1.125" was obtained by measuring and averaging 10 P9HST2s. The P9HST2 is loaded as long as possible.
Federal does not publish load data for the HST. 1100 fps is
fast for a 147, but that's what I got with the KKM barrel. I initially published the amount of Blue Dot in this article, then realized it was 10% beyond any published limits, so I removed it.
I pulled 10 P9HST2s, and Federal's powder load is 5.0gr(.323 grams) +/- .003g. I weigh these within .001g - the limit of my scale - because 9mm is twitchy at high pressures - be careful.
