Author Topic: machinist fix for a 45colt blackhawk "Has anyone tried this?" (Read 3293 times)

TMAKER · « **on:** October 26, 2010, 03:59:28 PM »

My 45colt blackhawk has .454 troats and end shake. I am a toolmaker and was thinking about hard chroming the troats and pivot hole undersized and jig grinding them back to correct size.
Has anyone tried this approch to fixing a sloppy fit on a single action revolver?

tomray · « **Reply #1 on:** October 27, 2010, 03:54:13 PM »

Tmaker,

Never tried that, but NO reason it can't be done...............the throats won't blue, but so what?.... With hard chrome, they won't erode either.................I think you can do it.

Tom
NRA LIFE

gcrank1 · « **Reply #2 on:** October 27, 2010, 05:53:08 PM »

What does your barrel slug at?

tomray · « **Reply #3 on:** October 29, 2010, 05:23:03 AM »

Quote from: gcrank1 on October 27, 2010, 05:53:08 PM

What does your barrel slug at?

good point!,..................I didn't think to ask, but how does your throat dim compare withthe dim of the barrel bore?

Tom
NRA LIFE

BlkHawk73 · « **Reply #4 on:** October 29, 2010, 12:00:29 PM »

It's yours, go ahead and try. Just remember, if it gets messed up, you still own it.

TMAKER · « **Reply #5 on:** October 29, 2010, 04:32:56 PM »

The troats pin .455.
It wouldnt be the first thing I experimented with and it become a paperweight.
I will plug the barrel tomorrow. I plugged it 6 months ago and I forgot what it plugged. I do remember it was tight under the threads so I plan to firelap the barrel befor I do the cylinder.
I will probably
#1-pull the barrel and cut/polish the forcing cone
#2 fire lap the barrel
#3 hardcrome the throats and jiggrind them.

What is the perfect size relationship from barrel to troats?
Dose anyone have a print of the best forcing cone design {angle , depth , max diameter} ?

Luckyducker · « **Reply #6 on:** October 31, 2010, 01:09:10 PM »

I have always considered having the throats and the groove diameter about the same to be conducive to better accuracy.

gcrank1 · « **Reply #7 on:** October 31, 2010, 02:36:59 PM »

Chamber mouth dia. needs to be at least exactly groove dia. of the barrel and even several thou' larger than groove dia. works fine with cast bullets as long as they are sized to the mouth dia. and fit into the fire-formed case mouths of the brass.
If you havent done so yet, try bullets that fit the case mouth as above and set up a testing procedure to eliminate as much shooter error as possible, ie, off a good sandbag rest for example. If all you have tried so far are jacketed, or worse yet lead sized at .452, there are better choices out there and you may not have to resort to machining the piece.

44 Man · « **Reply #8 on:** November 01, 2010, 04:27:37 AM »

Most of us with that situation have just hunted around for a properly sized Ruger cylinder. They are out there and usually reasonably priced. The other option is to find a 44 Mag or .357 cylinder and have it bored to the proper dimentions. Ruger barrels are usually about .451 or .4515. With lead bullets and most jacketed ones a .452 throat is fine for accuracy. Even with your .455 throats, you'd be surprised how well it may shoot when loaded with .454 cast bullets. I personally don't mind shooting .454 bullets, but it bugs me when something is out of spec, and I'd likely change it even if it shot fine. I have a Colt right now with .455/.456 throats that shoots very well with .454 bullets. But I will likely change the cylinder at some point just because I know it 'should' be .452. I owned a fully engraved EMF Dakota from the 70's that had a .451 barrel and .457/458 throats! That would only shoot well with .458 bullets made for the 45-70. I found a .45 acp cylinder with .452 throats for it and it shot wonderfully after that. Good luck with your project. 44 Man
PS, one other option is to send your revolver back to Ruger to have a proper cylinder fitted. Ruger charges a modest price for this.

Frank V · « **Reply #9 on:** November 02, 2010, 11:44:35 AM »

Have you simply tried using bullets sized .454? A number of Colt SAAs have oversize chambers & have been made to work quite well with bullets just a bit oversize. A bullet .454 isn't really oversized for the .45 Colt thought.
Frank

TMAKER · « **Reply #10 on:** November 02, 2010, 03:30:10 PM »

gunbroker has bisley 44 and 357 cylinders fo sale occasionally I may try one or those. If I rebore a 44 or357 cylinder should I remove the barrel and setup the frame with the cylinder in it and latched into place and indicate the barrel hole to get the cylinder throats exactly on location with the centerline of the barrel?
My shop wil be vacant dirring christmass so I will have all the machines to myself. I plan to work on it then.
It shoots ..454 dia ok but since I know it isnt correct I digs at me.
I love thing that are broke so I can fix them

44 Man · « **Reply #11 on:** November 02, 2010, 04:36:37 PM »

Not necessary. Just get a reamer with 452 throats and a pilot to match the throat diameter of the cylinder you are reboring. Simple with a verticle mill or a multi speed drill press. Enjoy. 44 Man

2 dogs · « **Reply #12 on:** November 03, 2010, 04:55:50 PM »

I would try a 454 or 455 dia bullet before I did anything.....you might be fixing a perfectly good shooting revolver!

flatgate · « **Reply #13 on:** November 13, 2010, 05:53:06 AM »

I don't see where you've "solved" your end shake situation. A common fix is to either tig weld some material on the front end of the cylinder or ream out several tenths and make a hardened bushing that can permit the cylinder to be "refitted" to the cylinder frame.

JMHO,

flatgate

Tallwalker · « **Reply #14 on:** November 18, 2010, 01:52:34 PM »

Cylinders in different calibers for the Blackhawks are different lengths to keep anyone from installing a .44 cylinder in a .357 for example. You will have to find one as long, or longer than the one you have if you go that route. I know the .357 is the shortest, but I can't tell you if the .44, or .45 the longest. I would expect that the .45 Colt is the longer one.

TMAKER · « **Reply #15 on:** November 18, 2010, 03:29:27 PM »

I planed to hard chrome the C/L hole and jig grind out to size to match the pin. It looks like I can buy an oversize pin to tighten up the frame to pin clearance cheaper than it can be custom made.

My 45 calipers 1.700"
anyone have a 44mag bisley the can measure the cylinder length over the chambers?

44 Man · « **Reply #16 on:** November 20, 2010, 03:05:53 AM »

ALL of the cylinders vary a little as to length as they were fit to a specific gun. But MOST of them will fit fine from gun to gun. If you get one that is too long, a little judicious filing will fit it up nicely. If too short, they make shims for that too. There is no plan of different lengths for different calibers. Yes, a belt mountain oversize pin will help, I need to put one into my Colt I have. Good luck with your gun. 44 Man

The cylinder in my SBH was swapped straight out, non-fluted cylinder exchanged for fluted. It had a little end shake and was shimmed. Works great!

gcrank1 · « **Reply #17 on:** November 20, 2010, 09:11:42 AM »

What is the acceptable Ruger spec. for end shake?

flatgate · « **Reply #18 on:** December 05, 2010, 09:53:09 AM »

Kuhnhausen states 0.0015" as a max.

flatgate

TMAKER · « **Reply #19 on:** December 25, 2010, 05:41:47 AM »

First of all I wish all of you a Merry Christmass!!!!

Well it looks like my shop will be working all through the holidays so the rework of the cylinder is on hold. I was able to skim cut the forcing cone and do a Taylor throating bore cut on the barrel. This made no difference. In the meantime I found out that Lipseys had 45colt blackhawk hunters for sale and bought one. I lucked out on it as the cylinder troats gauge pin .452 x 6 with a + pin so I think I am set on it.
Here is something I found while shooting the new 45. I loaded some .452 250 xtp over min load (Ruger/Contender only) of 2400 to sight it in. I use some brass that was sized while trying to develop the accuracy in on the old 45. While loading the new 45 I noticed that some of the brass wouldnt go in the cylinder without pushing and some just fell in. I tried the ones that wouldnt go in easily in the new one in the old one. They went in easily. I checked my sizing die in my press and found that it was locked down about 1/4" from the shell holder so the brass wasent getting sized all the way down. Evidently the old 45s chambers are badly oversized. I will measure them monday to see how much. I resized all the brass and have another 20 loaded up to tryout tomorrow. Will the uniformly sized brass make a difference in the way the old 45 shoots? I plan to load more of the 260gr hard cast .454 bullets tonight to see for my self.

Anyone want to bet a cococola on what the outcome will be?

Tallwalker · « **Reply #20 on:** December 28, 2010, 01:35:23 PM »

44 Man, this is one of the many prototype guns that I built from raw castings, etc. for Sturm Ruger during my 36 years there........... not a gun like this one, this one. If you will note the front sight is different from any production Redhawk. Now, I'm pretty sure of my sources, and information, but I could be wrong. Could you measure a few different cylinders that are different calibers, and post the results? Please be ready to back up your statements when you call someone else wrong............ I'm not upset, but I want the correct infomation posted.

To the OP's question: The throats can be chrome plated, and jig ground though grinding chrome isn't my favorite sport. My concern would be getting a smooth blend with the chamber balll seat, or tapered area on the chamber side. Though I have ground parts that were chrome plated, I have never done the plating, and am not sure what you would do in that area to achieve a smooth blend. Because of the way your cylinder was made, there is a chance that the throats are not concentric with the chamber now so that is another thing to watch out for. Good luck with your project, and keep us posted.

helotaxi · « **Reply #21 on:** January 15, 2011, 07:40:41 AM »

Calipers say that my .357 cylinder is 1.645"

Kuhnhausen lists the cylinder lengths on page 124.

BH .357 and .41mag - 1.64-1.65", .45 (auto and Colt) - 1.68-1.70"
Super BH 1.74-1.77"

.22-5-40 · « **Reply #22 on:** February 10, 2011, 04:28:49 PM »

Hello. TMAKER. I would check with Brownells to see if they have shim sets for fixing end-shake. I did this with an original 1903 Bisley..set up removable cyl/ bushing in lathe & just cleaned up face of bushing..maybe .002-.003" Used said bushings unser head & end shake is gone..nice & tight. I don't know about Rugers though. By the way..I'm a TM also.

44 Man · « **Reply #23 on:** February 19, 2011, 08:55:35 AM »

I stand corrected and appoligize for my ignorance. I have only worked with .44 and .45 cylinders and any difference I saw, I just chauked up to mfg tollerance. From a production standpoint, it just didn't make good sense to me for ruger to make different sized windows in the frame for different calibers in the same model. I was wrong. It's good to have someone that knowledgeable here with us. 44 Man

Lloyd Smale · « **Reply #24 on:** February 19, 2011, 10:22:35 AM »

im with 44man. First id see if it shoots as is. It may suprise you using 454 sized bullets. If it doesn i think for what youd get charged to do that work you could probably have ruger fit a new cylinder. they just fit one up in my montado and i think it was around a 150 bucks.

Quote from: 44 Man on November 01, 2010, 04:27:37 AM

Most of us with that situation have just hunted around for a properly sized Ruger cylinder. They are out there and usually reasonably priced. The other option is to find a 44 Mag or .357 cylinder and have it bored to the proper dimentions. Ruger barrels are usually about .451 or .4515. With lead bullets and most jacketed ones a .452 throat is fine for accuracy. Even with your .455 throats, you'd be surprised how well it may shoot when loaded with .454 cast bullets. I personally don't mind shooting .454 bullets, but it bugs me when something is out of spec, and I'd likely change it even if it shot fine. I have a Colt right now with .455/.456 throats that shoots very well with .454 bullets. But I will likely change the cylinder at some point just because I know it 'should' be .452. I owned a fully engraved EMF Dakota from the 70's that had a .451 barrel and .457/458 throats! That would only shoot well with .458 bullets made for the 45-70. I found a .45 acp cylinder with .452 throats for it and it shot wonderfully after that. Good luck with your project. 44 Man
PS, one other option is to send your revolver back to Ruger to have a proper cylinder fitted. Ruger charges a modest price for this.