load suggestions for 310 - 429 SSK

[Glaciers]

Ok, I have a mold from NEI when Walt was making the Sledge Hammer molds for J D Jones of SSK. I have used it in my magnum revolvers just fine for years, but, I went to run some thru my Browning 92 44 Mag and they were to long. So I cast up a small batch from COWW they drop at 327 grains and .432 dia., at about 12 BH. So I loaded some up in 44 SPL cases and the length right under 1.6. I'm at a loss as to a starting load, and then hotting it up. The smaller volume of the special case with such a lager bullet intruding into the powder room kind of has me going. I normally use 2400, but have H110, 296, unique, blue red and green dot, and others. The ones I loaded I used Trail Boss mainly as it would be safe and I could make sure the rifle would cycle properly. I have not found any listings for heavy bullets in manuals for the SPL, 250 is about as heavy as I've found.
So I'm wondering if any of you have had experience with heavy 44 SPL loads. I though I would take the starting loads for the SPL and reduce about 10% more with unique and start from there.

 

[358156 hp]

I have the same mould, and I've never seen any credible loading data for it in 44 spl. I've seen some wildcat data for 300 gr 44 spl, but they were pretty much at airgun velocities. One guy claimed to get 300 gr up to 1000 fps, but I felt his workup details were badly flawed, and I feel he was an accident waiting to happen. I found some data on the internet for 300 gr, mainly using either 2400 or Blue Dot. There was also a thread on CB a few years back on the subject. The main issue is that the bullets used were about 30 grains lighter than what you're using.

 

[RBHarter]

Thought process here , bear with me . No 44s but a RBH in Colts and loading 45 S&W +P in a 45 ACP platform .......

So we have a deep seated/short cased 44 heavy weight .
We want to shoot it in a 44 mag rifle .
We have a 44 special cartridge suitable for 14kpsi in a platform suitable for 40kpsi typically about 32-35 kpsi .
Found some data for bullets in class compiled from manufacturer sources on the Reloader Assistant app .

I'd start with Unique and find a load someplace between the max Special load and start mag load . Unique is flexible that way ...... Then because I have some QL data for heavyweight 45 Colts I'd start with more or less a fill to just touch the bullet base with H322 minus 10% if it doesn't light well use mag primers . The QL projected <20,000 psi filled to touch the base no compression in the Colts . Obviously not a good choice for revolvers but good for a rifle . The start load was 90% of the 20kpsi max with a 350 it ran over the Chrony at 1280 fps .

The 325 data listed here is a 1.6ish oal with typical slow pistol powders . 44 mag data with 1.6 oal start loads for 320 gr .
Oops .I got the max data on top .......