.460 Rowland--Yeah, it's for real....

[BEEMER!]

I have just bought a Clark Conversion and had it fitted to a Colt Govenment model.

I have Power Pistol, #7, and Longshot powders.  I will probably start loading 230 grain FMJ's as I have a lot of them.  Clark recommended starting with the 20# spring and move up to the 24# as my loads go up.

Where would you recommend starting?

First, I STRONGLY recommend slugging your bore and measuring the bullet diameters. While Longshot didn't seem to matter much, AA7 was quite sensitive to the overbore differential. Also, seat them as long as you can reliably feed them. I can reliably seat 230 gr. XTP's at 1.289", in my pistol. Start long, and reduce as necessary, but be sure to adjust and work up the powder charge accordingly. The big bullets eat up case capacity very quickly. Also note, my barrel is 6.6" with a tuned comp. YMMV.

Starting load recommendations:
AA7, 14.0 gr. start, 15.8 gr. MAX @ 1.275" COL.
LS, 10.6 gr. start, 12.0 gr. MAX @ 1.275" COL. (velocity began to plateau 11.6-11.8 gr., for me)

PP is too fast, IMO. Perhaps OK for plinkers (.45Super limit), but I would not recommend pushing it up. There are some PP loads published around the net, but it's far from practical, IMO. It may not get along with your comp, either. Autocomp and HS7 have some potential, though.

Blue Dot is also an excellent powder for the .460R, but I DO NOT recommend trying it unless you are experienced and comfortable with powder charge compression, which will be required for optimal performance. Forget trying any slower powders. They just don't fit!

Thanks for the advice. 

I thought that Power Pistol seemed a little fast, but the data I have seen listed it and it was on my shelf anyway.

I really like Blue Dot and I used to load it compressed in 357 Sig if I remember right.  Can you direct me to a source of information regarding compressed loads with it?

[DM1906]

Beemer!
There's not much to tell, and most .460R shooters are hung up on AA7 and Longshot, so not much help there, either. I suggest starting about 13.6 gr. Blue Dot with 230 gr. bullets and work from there. I got up to 14.8 gr, but I don't have a maximum, yet. I paused my workups due to weather at the time, and haven't got back to it. I will over the next month or so, weather permitting.

[BEEMER!]

DM1906

Thanks again.  Wanted to make sure I was not missing something.  I have loaded a lot of compressed rifle loads but not many in pistol or revolver cartridges.

[DM1906]

DM1906

Thanks again.  Wanted to make sure I was not missing something.  I have loaded a lot of compressed rifle loads but not many in pistol or revolver cartridges.

Blue Dot is a little different than spherical or cylindrical/tubular powders, in that it is medium size flat disc type flecks. Tapping the case on your press or bench after a powder drop helps to settle it. Or, you can settle an entire tray (I normally use MTM Universal) by placing a sheet of card stock or manila folder on top of the cases, then another tray (or other flat surface, with cases pinched between them), then use a massager on the top tray for a few seconds of subtle vibration. It may sound silly, but it settles them very consistently, which can be felt during bullet seating, and seating depths will be more consistent. The X-Treme 230 gr. HP's didn't start to "feel" compressed until about 14.4 gr. seated to 1.275".

[BEEMER!]

Good information, thanks again.

I used to load 338 Winchester Mag with 4350.  I used a funnel with an 8" drop tube and would still have to compress the powder.  One of the most accurate and uniform loads I had in the bigger calibers.

I could never get enough H110 in the 454 cases to reach max.  Very hard to compress also so I switched to AA#9.

[DM1906]

I understand the .454 and H110. It's the same with .41 and .44 Mag and monolithic bullets. I pre-compress to seating depth to allow seating with minimal force, which prevents bullet deformation (it's worth it). AA9 is OK, and so is 2400 (faster) and 4227 (slower). 4227 is a monster in long barrel .460 and .500 SWM, at significantly lower pressures than the others. 2400 performs much better than the others, if the barrel length is less than 4" in any of the above calibers.