I have been working on developing some hunting loads for my newly converted Ruger Blackhawk: a .475 Linebaugh. I am not new to hunting with revolvers, or shooting cast bullets in revolvers.
Actually I used to cast my own back in the 1980's; thousands of them, mostly .44 Magnum, but also .357 and even .308...
I want to share what I have recently learned on my .475 Linebaugh Load Project, in hopes that it may help somebody out there to not go through as much frustration as I have.
First off, as soon as I got my .475 built (Rod!) I started loading 325, 375, and 425 gr. cast bullets (cast by my friend Fowler). I tried 6 different powders and many different charge weights. Seems no matter what I tried, the gun would not group.
I then decided to try a JPoint red dot sight to see if that helped; it didn't.
So discussions between Fowler, Rod and myself, we decided to check the cylinder throats. They measured .476", whereas the sizer die was sizing them to .474". Two thousandths difference. Doesn't seem like much! So Fowler opened up the sizer to .476", (EDIT: Plus the barrel was leading up so Fowler also water dropped the bullets to harden them) and I loaded up a batch of those with 2400 powder.
To the range I went, and before shooting decided to check the JPoint sight to see if it was still mounted securely. I was shocked when I pulled on it and it rocked a little. Well, the factory iron sights were only held on with one screw, and also by a little horizontal pin that goes through the "ears" that the irons sit in, but the JPoint base designed for the RBH only had the one screw to hold it on. One could go to a gunsmith and have the JPoint factory base drilled to accept the little horizontal pin through the ears, I suppose. But why would you think that you have to "over-see and over-do" the JPoint Engineers; surely if that extra hole needed to be drilled in their base, they would have done that, right? Well, mine wasn't drilled. (Maybe the engineers had it right if you "only" shot .44 magnum loads...??? and not a custom .475) (Incidentally, JPoint has discontinued this base for the RBH.)
Ok, I tightened that base screw down as hard as I dared, and then started shooting. The gun immediately started to group. After weeks, my frustration was finally ending, heck I was ELATED to see that maybe I still DID know how to shoot a revolver.
Once I got it close to sighted in, I switched to a clean target and put eight holes in a fairly decent group. I then tried pulling on the JPoint sight again, and OMG it was LOOSE again! After "only" 23 rounds of medium heavy loads with the 375 grain cast bullet.
Now I realize that this target is by no means a record group, but please understand that this gun would not even come CLOSE to ANY kind of a group before! And the fact that the JPoint had again "shot loose", yet I still had some kind of a group, that makes it even better.
Solution:
The upper hole on Ruger frame shown was gunsmithed; ie, drilled and tapped. When the irons go back on, this hole will be hidden.
JPoint factory base shown NOW with TWO screws holding it to the frame:
Lessons I learned:
1. Shooting cast bullets is a whole different world in some ways than shooting jacketed bullets. It may take some effort to get them to shoot good.
2. Just because a factory gun part is built a certain way, does not mean that it is perfect or can not be improved on. I have always known this in the back of my mind, but still, don't you think those engineers.......
