Unique powder and the .45 Colt

[Gundogblue]

I have a Heritage Bigbore .45, and I really love that gun. I normally shoot the starting load of Trailboss powder behind a 250 grn RNFP boolit, but I get " blowback" carbon on the cases, so I thought I'd try some unique powder, and try to emulate factory velocity.
I cast my own boolits the .45 Colt is cast from the Lyman mould .454190, a 250 grn RNFP boolit. In my Lyman Cast Bullet Handbook the staring load for that boolit is 6.0 grns of Unique at 595 fps, and the Max load is 9 grns of Unique at 875 fps. lm thinking 8 grns of Unique should probably get me somewhere close to factory velocity, they don't list the pressure for those loads, but do ya'll think 8 grns of Unique is OK to use in that gum?
Thanks ,
Paul

[Drydock]

8 to 8.5 grains Unique is an all time classic load in the 45 Colt.

[Ranch 13]

 I have one gun that likes 9 grains of unique and another that likes 8. Best bet is to start and 7 and work up 1/2 grain increments until the target tells you it's a good place to stop.

[Froogal]

8.5 grains of Unique under a 200 grain RNFP is what I settled on. Been shooting that recipe for about 4 years now. I'm going to try black powder loads this year, but I will have the Unique loads with me, just in case.

[olskool]

since around 1992 i have been using 20gr. of H4227 with a mag primer and with a 250gr. cast boolit. i learned about this load from hank Williams JR. lately i started using 8.5 gr. of unique some. it shoots good but no better than my 4227 load.

[Coffinmaker]

  BLUE,

It's not going to matter a whole lot what/which powder you use.  Your going to get an amount of Blow-By.  There will be a difference in the amount of residue deposited on the cases though.  Some powders simply have a more dirty burn.  For handguns, it's not a really big concern.

[Coffinmaker]

I Forgot 

Should have mentioned, I don't particularly care for Uni-Que.  Never really liked the stuff.  My "Go-To" was TightGroup, which was before I became educated.  TightGroup also sooted up the cases pretty good.  I didn't much care though, just dump the cases in the tumbler and they cleaned right up.

Stay Safe Out There

[Trailrider]

A few other factors affect blowby in .45 LC. Many of the guns chambered for that cartridge have pretty-much oversized chambers. Second, the thickness of the case walls do vary from manufacturer-to-manufacturer, and so does the hardness of the case. If you are curious enough, measure the water capacity of different brands of brass after one firing.  The greater the case capacity, the chances are the walls are thinner, as the outside dimension are pretty standard. The amount of blowby may only occur partially down the case. It is more important (annoying) in rifles, when the case doesn't expand enough, quick enough to allow the powder gas to escape the action. 8.0gr. Unique under a 250 gr cast bullet is pretty much the "standard".  You might also try W231/HP38, which is faster-burning, and may expand the case more quickly, albeit it doesn't take up as much room in the case.
Stay well and safe, Pards!