Yep, and some barrels are simply slower than others, even in autos with no cylinder gap.
You really can't compare the two because the original 45 Colt ammo used a healed bullet which left more room in the case for powder. It was also a lead bullet, not a jacketed bullet. You can push a 250gr Cast Bullet to 900 fps with smokeless powder today because they produce less resistance in the barrel requiring less powder to push the bullet.
I stand corrected. I knew the bullet allowed 40gr of BP but I got the reason wrong.
Your going to be hard pressed to find data for that kind of velocity from a New Vaq, as they are considered the weaker frames and as you stated similar pistols with a few extra inches of barrel max out around where you want to be. In other platforms hitting those speeds and then some is no problem, I push some pretty insane speed loads from my Model 25, BH and lever guns but the Colts, clones, New Vaq etc just cannot handle the pressure. What you may try to get close though is Lil Gun behind a standard primer and work up a ladder. This powder produces excellent velocities in my hot .45 Colt loads. Also may I ask why you want that specific velocity of 850-900? My favorite load to date for the weak frame .45 Colt with the 250-255 grain bullets uses Blue Dot. It only pushes around 740-760 from a 5-6" revolver but is an absolute tack driver of a load and is very easy on the guns and economical to load. If accuracy shooting is your endgame I would suggest trying some of that, if hunting power is what your after I would try the Lil Gun. Good luck!
I stand corrected. I knew the bullet allowed 40gr of BP but I got the reason wrong.
I never claimed to be perfect and I keep proving I'm far from it!
With modern brass, it's hard to imagine how 40 grs ever fit in a case. Even with the balloon head case, must have needed a lot of compression.
This is true for sure; depending on the condition of the chamber and barrel you can see significant velocity differences between different examples of the same model revolver. For instance I have two M25s; one is +P rated one is not as they are different gen revolvers but both the same gun. However the +P rated example is always a solid 35-50fps faster with a given load than its sibling. This is the pistol I load hot for as well as a BH and a couple lever action carbines. I use nickel brass for these loads so as to never use them in my other .45 Colts as it would no doubt grenade them. (You do not in fact need the extra case volume of the .454 Casull to get .454 Casull like velocities, it's totally possible with standard .45 Colt brass but the pressures are so high that they do not want them accidentally getting into a weaker .45 so they use the slightly longer case.)
Why? Hunting. Accuracy is nice for paper. Hunting requires enough penetration and accuracy to hunt black bears and wild hogs...not to mention deer. In developing loads for hunting you have to find a compromise between accuracy and firepower....leaning toward penetration and stopping power.
Why? Hunting. Accuracy is key if all you shoot is paper. But when hunting, you need a load strong enough for the game you are hunting. Your load must provide deep enough penetration, sufficient wound capacity to kill the game quickly, and as accurate as possible. Some reloading manuals such as Hornady will recommend an accuracy load, and a hunting load. When hunting black bears in the northeast, you want to be sure your load is sufficiently capable of taking the game. Yes, I could use a 44 magnum or greater, but I choose the 45 Colt because it has taken such game throughout many years. I could also hunt such game with some horribly outrageous magnum rifle as well, but I choose not to. Velocity makes ft/lbs. Ft/lbs create stopping power. etc etc....
