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.45 Colt
Ambrose
Member Posts: 3,164 ✭✭✭✭
I've been experimenting lately with my Ruger Blackhawks and Rossi 92. I shoot over the Oehler 35P sky screens. One of my "standard" loads is a 250 gr. cast bullet with 10 gr. Unique. The 4.6" Blackhawk averages 1025 fps, the 5.5", 1050, and the 7.5", 1124 while the 20" Rossi runs 1205. It seems surprising that 3" of revolver barrel increases velocity 100 fps while the 20" Rossi barrel adds only another 80 fps. Unique is somewhat fast burning so it must be like the .22 LR, in that the powder boost runs out in a given barrel length and the bullet "coasts" from there on out. If I don't get distracted by another project (and I probably will), I should probably try a slower powder like 2400 or H110 to see if results change.
It's been fun!
Comments
An interesting experiment. The Lyman Reloading Handbook confirms what you are saying, but with jacketed bullets. Keep in mind that you can only push a lead bullet so fast before leading becomes a problem. Good luck.
If you want maximum performance you may have to develop two different loads for pistol and carbine.
There are other differences besides length. Chamber and bore dimensions vary and you might have a "fast" short barrel and a "slow" long barrel. Look at Ballistics By The Inch to see velocity from the same barrel sawn off an inch at a time. http://ballisticsbytheinch.com/calibers.html
The .45 Colt was my first big-bore revolver round. I loved it, but I never loaded it as hot as you do.
THE most painful gun I ever owned for it was an 8" or 10" featherweight octagon barrel on a T/C Contender. Talk about vicious recoil! I don't recall the exact length because I only owned it for about 10 shots.
In several Blackhawks of both common lengths, I settled on 250ish cast bullets at 900 fps. One of them penetrated a yearling buck lengthwise, entering in his chest and exiting just ahead of his left hip. Left a tunnel all the way.
If you cast your own, do get yourself a Lee RNFP mould. I think it's a 255 gr. One heck of a great bullet, that.
Agree with Hawk. Bore diameters vary and will cause differences in FPS.
IMHO, would rather use a slower burning powder that fills the case or at least most of the case on the 45 Colt when going hot. Accuracy will improve and its safer and results more consistent.
Also for going hot on the 45 LC strongly recommend Starline Brass. Starline is thicker in the web area as well as walls. Another advantage of Starline brass in 45 Colt is consistency in both rim diameter & rim thickness.
I understand the sentiment that if you want to find out how hot you can load .45LC, why don't you just buy a .44 Rem Mag. Well, that is a problem for someone who has some guns chambered in .45LC - I have two Judges and they are surprisingly accurate, (relative of course), w/the solid round. This guy, (link below), seems to know his stuff on the subject:
High Pressure .45 Colt loads
https://chuckhawks.com/high-pressure45.htm
My advice has always been that the guys who publish reloading manuals have college degrees in ballistics. Unless and until you're smarter than they are - and can prove it - don't go past their limits.
The difference between a great hot load and a grenade is about two milliseconds.
There is always an optimum barrel length for a given load. Once the powder is all burned, there is no increase in pressure, rather a decrease as the gasses expand. Then the bullet does not just coast down the bore, the high friction of the bore and rifling can actually slow it down.
That's true, except that all the powder doesn't always burn.
We've all seen loads where there is unburned powder left behind. A classic good but inefficient load is 4227 powder in the 45 Colt. You can get good consistent speed and velocity spread, but there will be enough powder left behind to bind up a revolver cylinder after a few shots.
There just comes a point in time and space when the receding bullet drops the pressure enough that combustion effectively ceases.
I've gotten pretty mild recoil from a second generation 5 1/2" SAA running a 250-gr lead bullet with slick coating on it and I believe 5.0-5.3 grains of Winchester 231, though I'd need to double check the powder loadings. My brother likes the same load in his revolver too, though his is also chambered to run 454 Casull and something else that I can't recall right now, so he calls the 45 Colt loads "baby loads".