Checking barrel alignment on OM BH

[J Miller]

I have an Old Model BH in .45 Colt. Several years ago with Iowegan's assistance I re-cut the forcing cone due to corruption from the bullets hitting off center. At that time I had a Belt Mountain base pin in it and that had raised the cylinder up and put it out of alignment. This was confirmed by visual examination, you can see the miss alignment when you look down the barrel, Iowegan's most excellent range rod, and the out of alignment burn marks on the face of the cylinder.
Forward to now. This problem has never fully been eliminated. I went back to the OEM base pin and that helped, but the cylinder is still out of alignment with the barrel.

My question is this; is there a way for a home gun tinkerer to check to see if the barrel itself is in proper alignment with the frame ~and~ if the center line of the bore is in alignment with the OD of the barrel?

I know Kuhnhausen's book shows some dandy jigs and tools, but I don't have those nor do I know anyone who does.

Joe

 

[rugerguy]

well the trouble is ,if ANY of the so called 'specs' ( drawings , dimensions and their tolerances), if any one item is drilled out to the low spec for one hole and the opposite for the next hole, this compounds and it'll be off twice as much??? possible...also, if the center pin holes ( two) are drilled on a "angle" (downward to either end) same thing........ thats why the 'big boys" for lack of proper wording, "line bore", match bores to each other as well as the frame, with their custom stuff, this will not happen...I doubt if you'd want to "move" the barrel, BUT, what if the barrel is "bent" ( say "downward) and yes ,we've seen this happen, from "misuse" ( like beating a wild boar on the head with ones, barrel of the gun......)
almost have to have one of the custom guys take it and measure (gage) it all out, to "see" just what is "amiss"....yes, opening the forcing cone is about the easiest and simplest, but may NOT enlarge (move) center to center, enough...........we also have seen this when folks "swap" barrels, and use the wrong technique and "spring" the window of the cylinder frame............""stuff" happens.........if it was a 'new model' you could send it back, but not in this case....its too late??? you could "try" and ask.....never know..........

 

[J Miller]

Dan,

I'm not to worried about sending it back to Ruger, other than if the problem was in the cylinder frame I'd lose it. If Ruger "fixed" it by replacing it I'd end up with a new model. I suppose that kind of "fixing" is extraordinary by today's standards, but I kind of like the old model.

As far as the barrel being bent, it wouldn't surprise me. It was very little if any used when I bought it. No blue wear on the breach face at all. But right from the start it shot way high and the front sight was tilted to the right. I had to have a really tall front sight put on it.
The gunsmith said he had to remove the barrel, shave a tiny bit off the shoulder to thread it in cos it was already way tight.

So, I have a lot of potential problem areas ... frame, barrel, base pin holes, or a combination there of.

Oh my.

Joe

 

[rugerguy]

well he may have a pont there, if he says it already was "too tight..."ever know, doesn't take a whole heck of a lot of 'force' to tweek a frame,but my bet is thats NOT it.........I'd guess the "stacking tolerances" mainly of the pins', two holes ( angled)
those range rods do work, help find out just what 'aligns' with what, that they are "concentric to the bore"........(heck, maybe the bore is "off")
how often does one "see" the center pin, be 'off' just enough that even the cylinder itself is "off" in any direction, and will bind something terrible just trying to remove and install the cylinder.........gotta ALL be "concentric", at least "close" enough and they usually are...........................

 

[flatgate]

And, now we know why Line Bored cylinders are such a good thing.

Joe, in your case, I'd rely on Iowegan's range rods to give you answers.
Up/down misalignment is gonna be a tough nut to crack. The cylinder latch can be shimmed a bit to help correct side to side misalignment.

If the trouble is indeed barrel to frame misalignment it's gonna be a tricky fix. A quick trouble shoot would be, perhaps, to pull the barrel and gauge the "shoulder" and check out the front of the cylinder frame.

Hmm, how bad DOES it shoot?

flatgate

 

[J Miller]

flatgate,

When I can see what I'm doing it doesn't too bad to 25 yards. I haven't shot past that in some time. The nearest available outdoor range is almost 50 miles away from me.

I've used the range rod and it does show mis alignment. And if you look at the face of the cylinder you can see it in the carbon deposits.

From what I can see it's most out of alignment at the 7:00 and 8:00 position when held in the shooting position.
I've never shimmed a latch but I've seen Iowegans pics on how to do it. That might help some.

This is the Ruger I've been considering rebarreling to 4-5/8". I've always preferred the short barrel, just haven't found one I can afford at the time I could afford it.


Joe

 

[texaswheelgunner]

J Miller, I bought a "like new" OM .45 too about 2 years ago; from the looks of the recoil plate, it had never even been fired.

It was shooting way high and way, way to the left. Took it to Alex Hamilton and he had the same comment about the barrel being in really tight. Had him build up the front sight on the gun too, just like you had to.

So far, mine has not shown any (obvious) miss alignment.

Please keep us all in the loop on developments. I'll sure bet Jim Stroh could fix that gun.

 

[Jimbo357mag]

The base pin is what holds the cylinder in alignment. Is it possible to adjust the base pin hole in the frame to bring the cylinder into alignment with the barrel? Perhaps re-drilling or a bushing?
...just thinking. :D

...Jimbo

 

[DGW1949]

I once encountered an OM 357-Blackhawk frame that had the 2 base pin holes out of plumb with one another. It weren't off much, but too much to allow an .0005-oversize pin to enter the rear hole. You could actualy see that the half-installed pin was hitting the lower edge of the rear frame hole. Another clue was that a Ruger pin would fit somewhat loosely into the front hole but got real-snug after being inserted through both.
The only fixes I could think of was to rebore the frame hole(s) and install an offset bushing....or two. Other than that, it'd be a weld-up and re-bore thing. After talking it over with a couple of gunsmiths, my thoughts was confirmed. Such things are way above my skill set and at the time, the cost of a professional repair would have been dern-near what I had in the gun. So I let it sit for a while.

What I finaly did with mine was strip it down, sold-off all the parts online and then sold the frame to one of them guys that builds fast draw guns. And yeah, I was completely up-front with the guy about the misalignment issue.
All told, I ended up with more money than I had in it to start with....and enough to buy myself a replacement gun that was more to my liking.

There's allways more than one way to skin a cat.

DGW

 

[J Miller]

As far as the base pin goes I doubt it's the issue. The Ruger OEM pin is a nice smooth albeit loose fit, and the Belt Mountain pin I bought was a smooth non binding fit as well.

If the base pin holes are off, they're both off equally.

As hard to come by as Old Model .45s are, this one is not a candidate for parting out. I'll just shoot it till it won't shoot no more then have it fixed.

Joe

 

[Boxhead]

Joe,

For not a pile of $$$ I suspect Alan Harton can build you a factory looking cylinder properly set up and leave you with a perfect piece. You might want to touch base with him, you may be surprised.

 

[J Miller]

Boxhead,

I think I'll just wait a while til I can get it diagnosed before I commit to spending lots of $$$$.
I'm sure Alan Harton could really do a bang up job on it.

Joe