I'll start out by saying this was more a quest of economy than of breaking barriers, and I've stuck close to book loads (Hornady and Lee, the former being more conservative). My original goal was to find the cheapest bullet that will hold about 2 MOA with a cheap and economical powder, that I can also use in my other reloading calibers. Also, high velocity is not preferred since I shoot a lot of steel. For some reason I want to convince myself that LilGun is not the end-all-be-all for the 450, so to date I have tried six different (albeit two of those are "equivalents") powders. When Midsouth Shooters Supply does their powder promo (Free HAZMAT w/4 lbs Shooters World) you can really score a good deal depending on what you like to load, so I'll finally get to it.
Shooters World Powders I've tried fast to slow:
Heavy Pistol: AA9 equivalent. Looks promising for the 230 HAP. Also works well in my 10mm, so +1 for compatibility. Meters great.
SBR SOCOM: Supposed to be for the .458 so figured I'd try it. I can't recommend it at all. I've had erratic SDs (in the 40s), high ES (100s) and poor accuracy 230-300 grain. "Book max" did not yield expected velocities. Not worth my resources to keep trying.
Blackout: Supposed to be a 1680 equivalent, but since I've shot 1680, I can say that its a tad faster. E.G. Book max of 1680 (41.7) for 300 grain XTP yielded 1866 avg fps. 40.4 grains Blackout yielded 1890. VERY low S.D. across all groups that I've shot, lowest being 4 FPS, which I shot in an interesting test that I'll likely get to later. Bottom line is I really like this powder for the 300 grain bullets, poor velocities, sooting, and unburned powder with the lighter bullets.
Now on to the HAPs. Since I played around with Blackout, 1680, and SOCOM with other 230 grain FMJ-FP to poor results, I didn't attempt with the HAPS. I stuck with only the fast powders of Heavy Pistol and LilGun.
Bullets were all seated to 2.1" and taper crimped to .474", a tighter crimp being required to hold it from seating itself deeper on feeding. In terms of feeding, I've yet to have a FTF, so the nose profile works well from the magazine.
Heavy Pistol (AA9) work ups:
33 grain - 1897
34 grain - 1905
35 grain - 2033
36 grain - 2083
36.5 grain - 2116* This is near the Lee book max load and is where I stopped. This provided a 1.6" 100yard group. S.D. weren't the best during work ups, but got smaller as the load increased. I have 10 more of these loaded waiting for a sunny day.
LilGun
I had already done workups on LG and settled on 39 grains. These also had a semi-high SD with averages around 2440 fps. My sample 4-shot group size was 2.3", three of them at 1.7". I have 10 more loaded up waiting to again to test.
Other important details to my personal criteria include impact shifts from my sighted in 300 grain XTP load. The Heavy Pistol loads showed most promising at 3" high, centered. The LG patterned 3" high, 3" right.
The Heavy Pistol group was aimed at the center bullseye, the LG group at the bottom left bullseye.
That's it for now until next time I can shoot the HAPs. Another interesting project I experimented on was resizing the 300 grain XTP to .451 with the Lee sizer. This actually yielded marginal, but good results. I loaded 10 identical bullets with 40.4 grains Blackout, same crimp and seat depth, however, 5 of them were control and 5 resized to .451.
.452 - Avg MV 1875, SD 10, group top left
.451 - Avg MV 1890, SD 4, group top right
Also, since you're looking at the picture, bottom right is the SOCOM powder...
I've got a handful of the 275 XPB and 300 grain FTX-ML, but I'll save those for another time.