I cant find any reloading data for .45ACP with 300gr slug

[YoungButOldSchool]

I was lucky enough to be given a 1911-A1 by my dad and I've thoroughly enjoyed shooting it and learning how to reload.  I've mostly used Unique and 230 grain lead round nose slugs.  I've found 5.5 to 6.0 grains of Unique to be a good load for me.  
My next little project is trying different weights and I bought samples of 155 grain and 300 grain.  I found info for the 155 grain slug on Alliant's site but nothing about 300 grain.  I'm guessing the pressure would be much higher to push a heavier slug down the barrel so I would start low, I'm just wondering if anyone has reloaded with 300grain .45ACP slugs?

[R. Tillery]

I've never loaded 300 grain bullets in the .45ACP, but I HAVE loaded 255 grain LSWCs. They are GREAT on bowling pins and wild boar! I got my load info from SPEER, more specifically, I used data for the .45 Auto Rim.

[Mikey]

R.Tillery - what powder charges are you using with that 255 gn lswc?  Did those loads come from the loadmap data?  

YBOS - you may not find any loading data for the 300 gn bullet in the 45 acp.  And, what diameter bullet is that you have thought about using.  You start going overbore in a low pressure cartridge like the acp and you might encounter more trouble than it is worth.  It is difficult to think of a 45 acp load in 300 grain that you could not almost outrun to the target.  

For the 230 gn, either jacketed or cast, good Unique loads run from 5.5 grains to 6.5 grains and goes on to 7.2 grains from my old Lyman manual.  That manual lists the factory duplication load of 877'/sec with 6.5 grains of Unique powder.  The accuracy load is at 5.5 grains of Unique.  I would suggest you invest in some reloading manuals to help preserve that 1911 you Dad got for you.

You have also mentioned wrist pain in one of your other posts - my suggestion to help deal with that is a set of heavy duty recoil springs from Wolffe Springs in Pa.  Your 45 comes with 16-18lb recoil springs - I regularly install a 22lb recoil spring kit in all my 45s to help manage the recoil of the 230 grainers.  HTH.  Mikey.