Ruger 22/45 Mark III

If a survey was taken on which rimfire handgun was most likely to be brought to a gunsmith in pieces, I’m guessing it would be one of the Ruger rimfires, such as the Mark I, II, or III, or one of the 22/45 versions. The owner of the 22/45 in this article was honest and said he disassembled it for cleaning. He followed the instructions in the manual but just could not get it back together and functional.

It was the well-known issue with the mainspring housing and hammer strut that has frustrated owners for many years and led Ruger to change the design and eliminate the problem with the Mark IV models. I appreciated the owner’s honesty, rather than giving a lame excuse like blaming a friend or brother-in-law. William B. Ruger, Sr. is well known for his innovative gun designs and manufacturing processes. He and his partner, Alexander Sturm, formed Sturm, Ruger & Co. in 1949.

Sturm, an artist and author, designed the heraldic eagle medallion for the handgrips and it became the official logo for the corporate literature and advertising. Sturm also provided the start-up capital for the company. It could have been worse. What is less well known, in 1938 Ruger started on a design for a light machine gun for the U. S. Army. In 1940, the U. S. Ordnance Department issued a Request For Procurement for anew light machine gun to replace the M1919 Browning.

They were looking for anew design, not just a warmed-over version of the M1919. Ruger saw the RFP but did not have any manufacturing capacity so he approached the Auto-Ordnance Company for help. Auto-Ordnance thought Ruger’s design had merit and agreed to build a prototype to submit for the RFP. After just five or six months they were able to provide a prototype for the tests. There were four other competitors, three of them (Springfield Armory, Rock Island Armory, and Colt) offering revised versions of the M1919.

Part of the test requirements was to fire ten thousand rounds without failure. The Ruger design did not pass the test and generally demonstrated poor reliability. The updated M1919s passed the tests but the Ordnance Department rejected all of the competitor’s designs, still wanting something better. The Ordnance Dept. liked Ruger’s overall design, saw the potential in it, and ordered a second round of tests in 1943.

Ruger and Auto-Ordnance revised their design and submitted a second prototype but it proved even less reliable than the first. While this was going on, the Infantry Department was looking for a lightened version of the M1919 for use by paratroopers. Their testing and development efforts resulted in the M1919A6, which also met the requirements from the Ordnance RFP, so the M1919A6 was adopted across the board.

Ruger learned some valuable lessons from the experience, his design abilities were recognized, and he did further work with Auto-Ordnance and Springfield Armory before starting his own business. Ruger’s first commercial success was the iconic Ruger Standard Model .22 semi-auto pistol that went into production in 1949. To reduce costs, the pistol frame was

The bolt is rotated 90 degrees to show the recoil spring assembly and hole for the bolt stop pin. made from two steel stampings that were welded together with the weld seam ground smooth. The receiver was steel tubing and the barrel threaded into the receiver. The magazine held nine rounds. It was similar in size and shape to the P08 Luger, which added to its appeal, and it pointed and shot well.

The Standard Model had a tapered 4.75" barrel; a Target Model was later introduced with a 6.0" barrel and an adjustable rear sight. During 1950 and 1951, minor changes were made to the design, primarily to reduce production time. After that, the basic design remained unchanged until 1982. Alexander Sturm died in November 1951 at the age of 28. Ruger changed the color of the medallion from red to black in honor of his partner and friend. One million of the pistols had been sold by 1979 after 30 years of production.

In 1982, the Mark II was introduced. Design changes included a ten round magazine, a bolt hold open lock, and scallops cut into the rear of the receiver, making it easier to grasp the bolt. Blued steel and stainless steel versions of the standard and target models were available. The 22/45 model was introduced in 1992. It was a variation on the Mark II with a Zytel polymer frame and a grip angle similar to the 1911 pistol.

The grip panels were molded into the frame and the magazine release button was moved from the bottom of the frame to the left side of the grip. These changes permitted a price that was lower than the standard Mark II, though the Mark II continued to sell in high volumes. The Mark III was introduced in 2004. The magazine release was moved from the bottom of the frame to the left side of the grip (like the 22/45) and a loaded chamber indicator and magazine disconnect were added as safety features.

Stainless steel Hunter and Competition models were offered. In 2016, the Mark IV was introduced. It has a much simpler takedown design; pushing a button on the rear of the frame allows the receiver to be tilted forward and removed from the frame. Reassembling the action is just as easy. It has ambidextrous safety levers that are easier to manipulate than the previous design. The original two-piece welded frame was replaced with a one-piece frame in aluminum, stainless steel, or polymer.

Combined volumes of the various Mark models total more than four million produced and sold. Bill Ruger died in July 2002 at the age of 86. His many designs over the years included not only rimfire handguns and rifles, but innovative centerfire handguns (revolvers and autoloaders), rifles (single shot, bolt action, and autoloaders) and O/U shotguns. He is regarded as a genius in the design, engineering,

This view unfortunately cannot be seen with the receiver installed on the frame. and manufacturing of firearms, in the same league as Samuel Colt and John Browning. Sturm, Ruger & Co. has produced over 40 million firearms since 1949, which is quite an accomplishment. About the only complaint on the Mark I, II, and III Ruger pistol design is the difficulty in reassembling the mainspring housing and bolt stop pin into the frame, and getting the hammer strut correctly positioned.

The same issues apply to the 22/45 models but the assembly procedure is slightly different and that’s what I’ll address in this article. Disassembly If you are starting with an assembled gun, remove the magazine and make sure the chamber is empty. Install an empty mag to disengage the magazine safety. Pull the trigger to drop the hammer and then remove the magazine. All the disassembly and assembly is done with the safety in the "fire" position.

The mainspring housing assembly (52) is located in the rear of the grip. It is removed by pulling the latch (60) downward using a paper clip or similar tool to hook the end of the latch. The housing will swing out of the grip and then it is pulled downward to remove it from the frame. The mainspring housing can be stubborn so it may be necessary to tap on the bolt stop pin where it protrudes from the top of the receiver with a plastic tipped hammer and a short wooden dowel.

With the mainspring housing removed, the bolt is removed by sliding it rearward. The receiver and barrel assembly is pushed forward and lifted off the frame. Light taps on the rear of the receiver with a plastic or rubber mallet may be required. The frame, receiver, bolt assembly, and barrel on this 22/45 had been cleaned fairly well. The bolt had not been disassembled so I removed the recoil spring assembly (22), the firing pin retaining pin (18), firing pin (21), and the rebound spring and its support (19 & 20).

I cleaned these parts and the bolt. I checked the tip of the firing pin for any wear or deformation; it looked fine. The extractor (25) moved freely, having good spring tension and a sharp corner, so I did not remove it. I did some additional cleaning of the frame and then proceeded to reassembly. Reassembly The hammer (36) must be in the horizontal (cocked) position initially during reassembly.

If the hammer has been rotated too far forward and can’t be rotated to the cocked position, insert the mag, cock the hammer, and then remove the mag. Install the barrel and receiver on the frame with the lug on the frame aligned with the recess in the receiver. Push the receiver rearward until the end of the receiver extends slightly past the Far

end of the frame. If hand force is not sufficient to do this, put the muzzle on a padded surface and tap lightly on the rear of the frame with a plastic or rubber mallet. The bolt is reassembled in reverse order. When installing the bolt in the receiver, the bolt stop button must be in the released (downward) position. It is easy to move it to the hold open position without realizing it when handling the pistol and then wonder why the bolt won’t go all the way in.

Check that the rear of the disconnector (39) is pressed down and the hammer is still in the horizontal position as well when installing the bolt. Ruger 22/45 Mark III (Speci ications subject to change without notice) Now for the fun part: reinstalling the mainspring housing. To do this, the hammer must now be fully forward. Insert an empty mag, point the gun downward, and pull the trigger. Push the hammer all the way forward with a small tool through the slot in the rear of the frame.

The bolt stop pin in the mainspring housing is inserted into the rear of the frame and pushed upward through the hole in the bolt. It helps to hold the bolt forward while doing this. If the pin won’t go completely into the receiver, lightly tap the bottom of housing until it does. Make sure that the hammer strut is still pointed downward as the end of the strut fits into a socket on the housing. Holding the pistol with the muzzle pointed upward, pull and hold the trigger and push the housing into the frame.

It should be almost fully closed at this point. Release the trigger, remove the mag, and fully close the housing into the frame. The latch should snap closed, flush with the frame. Insert a mag with snap caps and perform a function check. If the bolt cannot be fully retracted, the strut is not in the socket. Open the housing, check the strut position, and repeat the steps as needed. I explained this procedure to the owner. We’ll see if he remembers it the next time. AG