timothy75:
Where did you get your suggested load of 20.0 grains of H4227 under a (presumably) 250 gr. bullet in the .45 Colt?
I can't find any reference to using H4227 in the .45 Colt in the Hodgdon Powder website. Speer No. 13 reloading book (1999) doesn't have it. Lyman No. 48 Reloading Handbook (2002) doesn't mention such a load. Lyman Cast Bullet Handbook (1980) doesn't have it.
What's your source? I wonder what the pressure is for such a load? It may be well beyond the capability of a Colt Single Action Army.
The Colt Single Action is not a particularly strong action, compared to the Ruger Blackhawk .45 Colt. Many of today's loads are designed for, and tested in, the Ruger .45 (Blackhawk or Vaquero), which are far stronger guns than the Colt.
Ibsenson, I'd urge caution when loading for that Colt Single Action Army. Ensure you don't use a stiff load, intended for the Ruger .45, in that fine Colt.
I realize that your Colt is newly made but it's still weaker than the Ruger.
Be wary of any loads you find posted on the net; ensure they are not intended for Ruger revolvers or Thompson Center single-shot handguns. Such loads will wreck the Colt with one shot.
My personal practice is to check all loads I find on the net against an impeachable source, before use. These impeachable sources include the websites of powder or bullet factories or recently printed reloading books.
I've seen loads for the .45-70, .45 Colt and .44 Magnum on the internet that are beyond the realm of over-pressure, they were downright insane.
This is not an indictment of timothy75. Perhaps he has a good, solid source for his suggested load.
My favorite .45 Colt load, since 1973, has been the Keith 454424 semiwadcutter, cast of wheelweights or harder, over 7.5 grains of Unique. This is a light load, bringing about 800 fps from my Ruger with 5-1/2 inch barrel, but an accurate one.
It is a maximum load in the Colt, however, according to the Lyman No. 48 handbook. I'd suggest you start at 7.0 grains of Unique, if you wish to try it.
Before I knew better, years ago I used to fire the 7.5/Unique load on occasion in my first generation Colt Single Action Army, made in 1874.
Colt Single Action Army revolvers built before 1900, with serial numbers under 192,000, should never be fired with smokeless loads. Never. They were not built for smokeless powder. I'm lucky I didn't blow the ol' girl to Kingdom Come.
Your newly manufactured Colt will take reasonable loads but don't try to Magnumize it. The 250 to 260 gr. bullet at 900 fps is plenty good for defense and hunting. You may raise that velocity a bit to 1,000 fps, through judicious loading, but it's doubtful that game or aggressor would notice the extra 100 fps if hit solidly, especially if a modern semi-wadcutter bullet is used.
I'd forsake any jacketed hollowpoint or softpoint bullets. They show no advantage over a good semi-wadcutter and they're far more expensive. The copper fouling is also tougher to remove than lead fouling.
I envy your recent purchase. Would that I could afford a new Colt. I hope you enjoy it a good, long time.