09/30/2025
I have just finished a traditional 5 shot R***r conversion to 454 Casull which is one of my favorites. The gun is headed back to the owner in WA state. It started as a 357 Blackhawk. The cylinder window was opened up to accomodate an oversized 5 shot cylinder at 1.800" dia. The cylinder was machined from 17-4 PH SS, heat treated to a RC 44 hardness.
The cylinder has been line bored to a perfect barrel alignment. Freedom Arms line bores all of their revolvers.
I welded a bolt block into the frame to ensure perfect alignment for the cylinder stop. The barrel is a Douglas Match Grade blank machined to 6" in length and .840 dia., Taylor throated with 11 degree forcing cone. I installed a Freedom Arms interchangeable front site, and a C**t ejector rod housing.
I set the barrel cylinder gap at .002 and .0005 end shake. The trigger was set back and set at 2 1/2 lb.
I round butted the Bisley grip frame and it was fit with Chiggs fancy walnut grip panels. The gun was finished out in high polished blue.
This is a follow up on the 454 Casull build. I've been contacted by some forum members as to what all was done to get that kind of accuracy from a reduced H110 load. There are several things that go into an accurate revolver. Having shot 1,000-yard bench rest I've learned the smallest detail overlooked is always the weakest link.
The one thing I need to correct was a type error on the Hunter Supply bullet, It's 328 grain not 325 grain. That bullet has proven to be very accurate as well a good performer on game. I learned that stress kills accuracy in long range rifles and I believe stress affects a revolver as well. When a revolver is fired there are several things that happen simultaneously.
The first step after making sure the frame is within spec. I filed the frame or grip frame for precision fit. Any misalignment when tightened together will induce stress under recoil. Then I replace the firing pin with a .008 longer firing pin and a reduced firing pin reduced return spring. This allows better ignition with lighter hammer spring with reduced hammer force to rear A-frame plus it gives a better trigger let off. While the frame is in the fixture for line boring and perfectly trammed in, I will make a light skim pass to ensure the barrel seat is square with the frame. A shoulder or seat out of square will have a tight spot which causes stress in the barrel as the bullet engages the rifling. That's one reason I always Taylor throat or freebore to try and create a gentler engagement.
Just the recoil alone will cause a barrel to have a tuning fork effect. Now as the bullet travels down the barrel, which can induce harmonics. Most of my Premier builds, I usually don’t turn a tapered barrel. This may or may not cause any stress but any time a cut is made there is a possibility of causing stress.
With a high-speed camera, when firing occurs there is a certain amount of movement. The frame, cylinder and barrel, movement always happens but the less stress the better chance of accuracy. One thing I've seen that is often overlooked is barrel to frame fit. I am finding that the frame threads are somewhat undersized on some guns. I'll run a thread gauge into check and if it's out of spec I'll open threads to proper spec. If threads are slightly undersized and the barrel threads are near full profile the top of the thread on the barrel can bottom out on a shallow V. 60° threads are designed to make contact on the side of the threads instead of the root. After I thread a barrel, I'll always flattop the threads with a file to not make any contact with the root. I've had guns come into the shop that have had the throats corrected even some have had new barrels installed and still don't shoot good groups. Even when fed quality ammo. When completing these upgrades, it usually makes a revolver shoot better, but also the same detail must be taken on preparing ammo. The group was fired from a Ransom Rest 5 shots at 25 yrds.
