You know what we just got? Some of this LT32 Benchrest powder. Load min/max look similar to H322. The powder kernels look similar too.
I'm going to sling a few 69 gr SMKs on Friday to get a baseline of the powder.
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You know what we just got? Some of this LT32 Benchrest powder. Load min/max look similar to H322. The powder kernels look similar too.
I'm going to sling a few 69 gr SMKs on Friday to get a baseline of the powder.
I have loaded a lot of 55gr FMJBT w/c Hornady bullets using 23.5gr of H322. I have tested CCI #41 primers, Rem 7 1/2 primers, Win SM Rifle and Wolf SRM primers with this load.
The highest velocities were with CCI #41. The smallest ES was with Wolf SRM. No pressure signs with any primer. Velocity with CCI #41 avg=approx 2880fps from 16" BCM 1:7 barrel. Velocity with other primers approx 50-80fps slower.
I found primer seating depth and preload to have a significant effect on ES and SD with all brands of primers. Using my Sinclair tool to seat primers exactly -.003 below the case head reduced ES by about 30% on ten round strings.
When I was doing these tests I was using once fired LC brass matched by weight to +-.5gr. They were trimmed to 1.750 +-.002 and neck expanded with a mandrel to .222 diameter (.002 less than bullet diameter). Bullets were "medium" crimped into the cannalure with a Lee collet die.
The powder makers max loads are usually tested in a min spec 223 chamber - think bolt gun. The extra free bore in a NATO chamber can lower peak pressure by as much as 5000psi so loading manual max loads are very conservative for a NATO chambered AR.
Thanks for mentioning the Sinclair tool. I've been wanting to add one to my god tools box for quite a while. The SD dragon is one that is hard to catch but as I get into longer and longer range shooting I am seeing its effect quite prominently at 500+ yards. The old 250 yard being long range is now out the window.
Greg
I've loaded Hornady 55s with H322 to match M193 velocity out of my 10.5" Noveske. 23.8gr with a CCI 450 or 41 primer, 2.190" OAL and a light crimp. It's very accurate for me and I see no signs of high pressure. I could post my chrono results when I get home today if you want it.