Introduction
I have many Ruger revolvers in my collection, most are in .45 Colt, but I also have two Single Sixes in .22/.22 WMR.  As a member of the Ruger Revolvers Only Facebook group I see many posts about the .30 Carbine Blackhawk.  I thought this would be an interesting revolver to own, especially since I own a commercial M1 carbine.  Since both take the same cartridge, it would be very handy to have when hog hunting or in a SHTF situation.  I found a used .30 Carbine Blackhawk on Gunbroker for $479 plus $10 shipping, and the dealer took a credit card with no additional fees.  After paying the $30 transfer fee from my FFL dealer I am now the new, proud owner.  The serial number indicates it was built in 1997.

.30 Carbine
The .30 Carbine cartridge was developed by Winchester and is basically a rimless .30 caliber version of the old .32 Winchester Self-Loading cartridge of 1906 made for the Winchester Model 1905 rifle.  The .30 Carbine is more powerful than its parent cartridge and has more muzzle energy than a .357 magnum.

This cartridge was designed for use in the M1 Carbine rifle, which was issued to infantry officers, machine gun, artillery and tank crews, paratroopers and other line-of-communications personnel in lieu of the larger, heavier M1 Garand.  It was meant to replace the M1911 handgun for those personnel.  Some people believe that the .30 Carbine was designed for use in pistols because of its relatively straight case and the rounded nose of its bullet. 

Initial Inspection

The gun was in pristine condition except for the ejector rod housing which was scratched and marred.  This was disclosed by the seller, which is probably why no one else wanted to buy it.  It looked like a previous owner had dropped it against something.  This housing was made of aluminum, but I had a blued steel housing I purchased from Brownells #850-200-200 which took me all of 5 minutes to install.  I cleaned and oiled the barrel under the housing and the housing itself and installed the retaining screw with a drop of Loctite blue.  The gun came with some very fat grips made from some artificial material.  There were some imperfections and blemishes on the grips, but they were just too fat for my hands. 

To my surprise, the gun was clean, but not up to my standard.  In fact, one chamber was still dirty because a cartridge would not chamber all the way.  I ran a bore brush then a cleaning patch soaked with Ed’s Red through the barrel and each chamber.  I also cleaned the base pin channel in the cylinder.  I dried everything off, then ran an oily patch through the chambers and barrel, followed by a dry patch.

I had a set of white polymer grips with Ruger medallions, but I don’t remember from where I purchased them.  These are standard sized grips and make a very nice contrast to the blue/black gun as you can see in the above photo.  I may eventually replace the aluminum grip frame with a steel one.

This gun came with a very odd ejector rod.  Two sides of the rod were milled flat and the end was flat.  Looking at the end it looked like a quarter of a pie.  I posted this on Facebook in the Ruger Revolvers Only group and the answer came back that this was required on large-frame Blackhawks that use small diameter cartridges so the rod doesn’t touch the cylinder when ejecting a spent case.

Installing a Belt Mountain Base Pin
In my collection of Vaquero/Blackhawk spare parts I have two blued Belt Mountain Base Pins.  These pins are slightly larger than a factory base pin which is supposed to eliminate cylinder wobble which could result in some accuracy improvement.  I had originally purchased them for my blued 4 5/8 Vaqueros, but I sold those two guns in favor of stainless steel 5 1/2 Vaqueros.  However, being a packrat, I kept the two Belt Mountain base pins and decided to install one on this Blackhawk.

The Belt Mountain base pin must be fitted in four places; the hole in the front of the frame, the hole in the rear of the frame where it touches the transfer bar, the hole in the cylinder, and the notch for the base pin latch.  To test for fitting, I removed the ejector rod housing, factory base pin, the cylinder, and the base pin latch.

The holes in the frame and cylinder measure 0.250; 1/4 inch.  The Belt Mountain base pin fit in the cylinder and front frame hole perfectly.  However, the rear hole in the frame had a small burr that prevented the base pin from being installed correctly.  I used a small, half-round jeweler’s file to remove the burr and the pin fit through the frame perfectly. 

The base pin latch would not fit in the notch in the base pin.  Following the instructions, I used a blue marker to mark the notch, installed it in the revolver, and tested the base pin latch for fit.  If it was tight, I used a mallet with a nylon head to gently tap on the base pin latch, then tap the threaded end to free it from the notch.  When I removed the base pin there was a white mark where the latch was contacting the notch.  This told me where I had to remove metal.  I used a half-round jeweler’s file to carefully remove a small amount of metal at the mark.  I remarked the notch with a blue marker and again tested for fit.  I continued to mark, test and file until the base pin latch fit into the notch.  I polished the notch with 400-grit wet/dry paper, then cold blued with Brownell’s Oxpho-Blue #082-024-004.

Finally, I replaced the factory base pin latch spring with a Wolff extra-power base pin latch spring I purchased from MidwayUSA.com #469178.  I reinstalled the base pin latch, spring, and nut and everything was working properly.

Installing a Lighter Trigger Return Spring 

I disassembled the revolver and replaced the heavy factory trigger return spring with a Wolff reduced power trigger return spring purchased from MidwayUSA.com #436652 (refer to my article Ruger® Single-Action Revolver Disassembly/ Reassembly and Spring Replacement).  This can greatly reduce trigger pull weight.  After I replaced the spring, the trigger pull weight went from 4 lbs. 2 oz. to 2 lbs. 2 oz.; almost half of the factory pull weight.  Some people perform a “poor man’s action job” by lifting one leg of the factory trigger return spring off the trigger spring retaining pin, but the loose leg can interfere with the hammer spring.  The correct method is to replace the spring with a lighter one.  Replacing the hammer spring with a reduced power hammer spring can also reduce trigger pull weight, but light primer strikes can affect accuracy, so I left the factory hammer spring in place.

Installing a Half-Cock Hammer

All Ruger Blackhawks, large-frame Vaqueros, and Single-Six revolvers have the same problem; if the cylinder is rotated backwards against the pawl, the chambers are not aligned with the loading gate.  This can be corrected by installing a Power Custom half-cock hammer.  With the hammer in the half-cock position the pawl is raised just enough so when the cylinder is rotated backwards a chamber is aligned with the loading gate and ejector rod.

I purchased the hammer from MidwayUSA.com #439111.  This is a special-order item, but it arrived in only one week.  I have installed these hammers on both of my large-frame Ruger Vaqueros (refer to my article Installing a Half-Cock Hammer in an Old Model Ruger® Vaquero®).  This time, the hammer came with the proper installation instructions. 

The hammer is a drop-in part, but the trigger and transfer bar both need to be modified.  If you don’t want to mess with the factory trigger, MidwayUSA.com sells the hammer with a new trigger and Wolff spring kit #345935, but the transfer bar still needs to be modified.  This full kit is more expensive, but I wanted to do the gunsmithing myself and save some money.

The following modifications need to be performed to the factory trigger and transfer bar:

• The top of the trigger sear needs to be milled so the sear is 0.040” thick to fit into the half-cock notch. 

• The bottom of the trigger sear needs to be radiused to fit in the curve of the hammer. 

• The safety notch in the transfer bar needs to be lengthened by 0.090” – 0.100” so the loading gate can be opened with the hammer in the half-cock position. 

I coated the sear with a blue marker and scribed the trigger down to where I would have to mill.  I used a 0.250 milling bit to mill off the excess metal from the top of the trigger.

I radiused the bottom of the sear with a small grinding bit and my high-speed rotary tool.  I was careful not to overheat the trigger because I didn’t want to ruin the heat treating.  I used the Ruger single-action hammer a trigger pin holes in the top of my Power Custom Series I stoning fixture to test for fit of the modified trigger into the half-cock notch on the hammer.  I polished and cold-blued the trigger surfaces I worked on.

Finally, I installed the trigger in my Power Custom Series I stoning fixture with the RSA adapter and used my fine and extra-fine ceramic sticks to polish the sear.  The original trigger pull was inconsistent at about 4 lbs. 2 oz. and was long with significant creep.  But with the reduced power trigger return spring and half-cock hammer, the new trigger pull is now 1 lb. 13 oz. and crisp with no creep.

With the hammer in the half-cock position, when I rotate the cylinder backwards against the pawl a chamber is lined up perfectly with the loading gate.  I tested to ensure the hammer would fully cock on all six chambers.  If not, the lower tooth on the pawl would have to be modified, but my gun locked up on all six chambers.

Every Gun is Different
Every gun is different due to manufacturing tolerances, and this gun was no different.  The Power Custom half-cock hammer was just a bit wider and thicker than the factory hammer which caused it to bind in the aluminum grip frame.  I used a file to remove the factory finish (which was thick like a paint) from the inside of the hammer gap in the grip frame, which no one will see, and lengthened the gap just a bit so the hammer wouldn’t bind.  I also had to file some burrs from the rear of the trigger cutout in the grip frame where the trigger was dragging.  Now the action is smooth with no drag.

I broke My Gun!

In the process of disassembling and reassembling the gun I broke the cylinder stop plunger.  This plunger presses against the cylinder stop – sometimes called the bolt – to return it to the raised position when cocking the hammer.  This locks the cylinder in place when the hammer is cocked and prevents the cylinder from rotating.  I think I didn’t get the grip frame aligned properly with the cylinder frame and applied too much sideways force which broke the plunger. 

I couldn’t find the part at Brownells or MidwayUSA and eBay sellers wanted $25 or more.  I found a used one at Numrich www.gunpartscorp.com for $8.95 plus shipping.  The shipping was almost as much as the part, so I also purchased a new trigger in case I had to return a modified gun to Ruger.  Ruger will replace any after-market parts with factory parts, so I always keep my factory parts.  However, since I modified the triggers on my two Vaqueros and this Blackhawk, I would have to replace those parts with the factory parts before sending any of them to Ruger for repair.

When the new plunger arrived, the inside was filled with some crystalline substance.  This may have been old oil or grease that had dried out.  I thoroughly cleaned and oiled the inside of the plunger, inserted the original spring, and reassembled the gun.  Everything now works the way it should.

Summary
This was a fun project and I now have a beautiful Blackhawk in my collection.