Eutectic
posted this
28 December 2022
Be still my heart!
It is nice to see all the interest in 45 ACP revolvers, which are dear to me. I have had 10 45 ACP revolvers. Why?? Read my article in The Fouling Shot 150 -151 it must be LOVE.
Yes, and maybe they are nice to shoot, very useful and can be accurate. First, I would rather not deal with the large cylinder throat problem. I take a 0.451 jacketed bullet with me to gun shows. Before I even try the lock-up and cylinder fit I want to know the if the cylinder throats are close to 0.451 and even. The barrel is almost always close to 0.451 so this is important.
Then I look carefully inside the chambers with a white card in front. I look at the area of the cylinder latch cut to see if there is a depression. This is the thinnest point and any dimple indicates over pressure loads have been fired. If you are looking at a 45 Colt gun this is even more important. If everything checks we can talk price.
The older 45 ACP revolvers had a sharp transition from the chamber to the throat. This cuts up cast bullets, leads the chamber and destroys accuracy, see my FS article. I had a Clymer reamer made to modify the throat to a revolver type entrance. It has improved the accuracy of every 45 ACP revolver I have owned. If you want to rent it send me a PM.
Ed Harris recommended a cheaper fix using a 30.06 case and fine valve grinding compound to remove the sharp shoulder. He lets enough of the shoulder remain so the gun can still fire without moon clips. This modification has been incorporated by S&W in 45 ACP revolvers made since ~2000. It improves accuracy with both cast and jacketed with no downside I have seen.
The 45 ACP case is small, an increase of seating depth of 0.1" can push normal pressure loads up to proof pressure or above!
With ~250 grain bullets like Accurate 45 -248H with a SD of 0.235", 4.9 gr. Bullseye gives 870 fs at max pressure. You can get ~1000 fs but you need slower powder. 7.9 gr. VV340 will do it as will 8.0 gr. Power Pistol or 11.4 gr. of Blue Dot. These loads gave case expansion equal to maximum loads from the Hornady manual in my revolvers. Work up carefully, use a pressure ring reference in YOUR revolver. No responsibility is expressed or implied for the suitability of this data.
So what do I use? Lots of 200 gr. SWC's at 750 fs, standard target loads many in Auto-Rim cases. If I need speed loaders, 230 gr. Accurate 45-231B with 4.0 TiteGroup or Bullseye and 750 fs for fun. A max load of TiteGroup or Bullseye if the match requires full power loads. For blasting bowling pins, the extra weight of Accurate 45 -248H is a plus and 6.8 gr.of Power Pistol gives 915 fs which is plenty. Accuracy of this load over a long series is improved with a 3/8" piece of 1/2" polyethylene backer rod as filler.
Steve