Howdy
I have Belt Mountain Base pins in several Rugers and 3 Colts.
First off, I too do not recommend the pin with the set screw, for two reasons.
1, it is a pain to keep that teeny little Allen wrench around if you want to pull the cylinder and do a little bit of cleaning at the range.
2, if you overtighten the screw just a teeny bit too much, it bends the pin, causing the cylinder to bind.
First time I tried a Belt Mountain pin in one of my Rugers that was my experience. All the Belt Mountain pins I have now are the type that does not use the set screw, and they all work great.
But they are not all a drop on fix for the problem of pins jumping forward under heavy recoil.
The real cause of the problem is the latch parts are not properly fitted to the pin. This is understandable because Rugers are mass produced guns.
Before changing the pin, try this test. First, remove the pin and the cylinder. Then pull the latch all the way to one side against spring tension and let it go. Notice how smartly it snaps all the way, and in particular notice how far it snaps. Then put the cylinder and pin back in and repeat the test. What happens? Does the latch snap smartly all the way over as it did when there was no pin present? It should. If it does not, if it only snaps part of the way, the latch and the pin are not properly fitted. When they are properly fitted to each other, the latch will snap smartly all the way over and prevent the pin from jumping forward under heavy recoil.
There are three (3) fixes for an improperly fit latch and pin.
1. Fit them properly.
2. Replace the latch spring with a stronger spring.
3. Replace the cylinder pin with a Belt Mountain pin.
Sometimes it takes a combination of a couple of these fixes to get a satisfactory result. If you only go the 2nd or 3rd route, you are addressing the symptoms, not the problem.
Ruger cylinder pins come in two varieties. One has the groove for the latch cut completely around the pin, the other has a single horizontal cut across the pin. The second type is the better pin because there will be more surface contact between the latch parts and the pin. There is less contact with the type of pin that has the groove cut around it. Belt Mountain pins are of the second type, with the engagement cut going across the pin. Because the cut is horizontal, the pin must be oriented properly when it is put in the gun or you will jam it against the barrel. No big deal really, you just have to be aware of it.
Here is what I have done with most of my cylinder pin fitting problems. I buy the Belt Mountain pin, without the set screw. Then I put it in place in the gun and try the test I mentioned earlier. Chances are, I will have to do a little bit of fitting. This is very simple. You take a Sharpie and ink up the groove in the pin. Then you put it back in the gun and try the test. Then you observe where the ink has been rubbed off the pin. That is where the surfaces of the two parts are in contact. Then I take a very small jeweller's rat tail file and remove just a tiny bit of metal where the ink has not been removed. Just a tiny bit. Then ink up the pin again and reinsert and try the test again. After a few trials, and removing just a tad of metal each time, the latch will snap smartly all the way to the end of its travel as it is supposed to.
I have done this with several Rugers and Colts, all of which are chambered for 45 Colt. After this treatment, the pin never jumps forward again, even with full house Black Powder loads.