WardenWolf
member
Well, I've mentioned in a few threads that I've been trying to fix up my father's 1972 Ruger Mark I pistol. I finally managed to get it done, though I haven't shot it yet. Here's a summary of what was wrong with the pistol, changes made to correct it, and some of the difficulties encountered.
1. Jamming
The original complaint with this pistol was constant jamming issues. My father never really looked into it, and so that fell to me. When I had the grips off, I noticed a mark that showed the magazine follower rivet had been dragging on the inside of the wooden grip panel. Obviously, even a slight reduction in magazine responsiveness can lead to misfeeds. I Dremeled a groove on the inside of the grip where it was dragging, and the jamming seemed to disappear. That, at least, was an easy fix.
2. Light Strikes
After successfully passing firing tests with no jams, the pistol was stored for a few months. The next time it was used, however, it frequently failed to trigger the round. The same rounds worked flawlessly in my Mark III, so obviously it was a problem with the gun. I tried honing the firing pin somewhat to improve strike depth, without success. During this disassembly it was noted that the recoil spring assembly wasn't in the best shape, with the rear legs warping and spreading. Used pliars to bend it back.
3. Jamming, again
While testing to see whether the firing pin honing did the trick, the gun started jamming again. However, this time it appeared that the cause was not having enough force to properly strip the round and chamber it. The aforementioned recoil spring was the obvious culprit.
Diagnosis:
It was obvious at this point that the pistol needed new springs. Unfortunately, it's not quite that simple or cheap. While Ruger does indeed sell just the springs, the spring assemblies were never meant to be user-serviceable. The original recoil spring assembly was held together by the peened end of the rod, and the mainspring housing is pinned together in multiple locations. Even if you could get it apart, it would just explode into a mess of springs and ball bearings and you'd never be able to get it back together.
So I call up Ruger, and verify that the newer Mark II and Mark III parts would indeed fit the Mark I, and place the order. I ordered a complete new mainspring assembly, recoil spring assembly, and a firing pin for good measure. It totaled $40 shipped before tax.
Installation:
The parts arrived, and I quickly ran into some problems. They were indeed the correct parts, but 39 years of parts tolerance differences can make for quite a headache.
The firing pin dropped in without a problem, but the forward part of the new recoil spring assembly fit the old bolt too tightly. A bit of work with a diamond file cleared that up.
The real problem came with the new mainspring assembly. The vertical strut / bolt stop that goes into the pistol fit very tightly and proved very difficult to install. And after installing, the bolt would jam to the rear when pulled. All attempts to figure out why this was happening failed. The bolt itself was more than wide enough to accomodate the strut, yet somehow it was catching. Even with the upper receiver completely off the gun, it still did it with this strut. The new and old struts were carefully compared and no notable differences could be found. Finally, out of desperation, I knocked out the pins and put the old strut on the new mainspring housing, and the problem went away.
Upon reassembly, I noticed the safety was not holding itself in the up (safe) position anymore. It turns out the safety knob can actually rotate on the piece, and it had simply rotated so the ball bearing was no longer positioned correctly to support it. A quick twist with pliars put it back. This is something to watch out for in the future, as it can easily happen and seriously affect the safety of the gun.
Conclusions:
So, looking back, here are my main observations:
(1) Very little has changed between the Mark I and the Mark III, except for parts in the trigger assembly.
(2) The spring assemblies are NOT user-serviceable. Don't even try it.
(3) Several decades of tolerance differences can cause a major headache.
(4) Watch out for that safety. If it rotates it won't say in the up position reliably. Verify the ball bearing is in the correct position, and use pliars to rotate the knob if not.
(5) Ruger's customer service is great. They answered my questions on parts compatibility and then transferred me directly to their parts department. I ordered the parts direct from the factory, and they were even less expensive than listed on shopruger.com, and a lot cheaper than on other websites.
Tools used:
old ball peen hammer
old Millers Falls 1/32" punch
1/4" brass punch
wooden block
Leatherman Charge TI (diamond file and pliars)
And a whole lot of caffeine, patience, and cursing.
1. Jamming
The original complaint with this pistol was constant jamming issues. My father never really looked into it, and so that fell to me. When I had the grips off, I noticed a mark that showed the magazine follower rivet had been dragging on the inside of the wooden grip panel. Obviously, even a slight reduction in magazine responsiveness can lead to misfeeds. I Dremeled a groove on the inside of the grip where it was dragging, and the jamming seemed to disappear. That, at least, was an easy fix.
2. Light Strikes
After successfully passing firing tests with no jams, the pistol was stored for a few months. The next time it was used, however, it frequently failed to trigger the round. The same rounds worked flawlessly in my Mark III, so obviously it was a problem with the gun. I tried honing the firing pin somewhat to improve strike depth, without success. During this disassembly it was noted that the recoil spring assembly wasn't in the best shape, with the rear legs warping and spreading. Used pliars to bend it back.
3. Jamming, again
While testing to see whether the firing pin honing did the trick, the gun started jamming again. However, this time it appeared that the cause was not having enough force to properly strip the round and chamber it. The aforementioned recoil spring was the obvious culprit.
Diagnosis:
It was obvious at this point that the pistol needed new springs. Unfortunately, it's not quite that simple or cheap. While Ruger does indeed sell just the springs, the spring assemblies were never meant to be user-serviceable. The original recoil spring assembly was held together by the peened end of the rod, and the mainspring housing is pinned together in multiple locations. Even if you could get it apart, it would just explode into a mess of springs and ball bearings and you'd never be able to get it back together.
So I call up Ruger, and verify that the newer Mark II and Mark III parts would indeed fit the Mark I, and place the order. I ordered a complete new mainspring assembly, recoil spring assembly, and a firing pin for good measure. It totaled $40 shipped before tax.
Installation:
The parts arrived, and I quickly ran into some problems. They were indeed the correct parts, but 39 years of parts tolerance differences can make for quite a headache.
The firing pin dropped in without a problem, but the forward part of the new recoil spring assembly fit the old bolt too tightly. A bit of work with a diamond file cleared that up.
The real problem came with the new mainspring assembly. The vertical strut / bolt stop that goes into the pistol fit very tightly and proved very difficult to install. And after installing, the bolt would jam to the rear when pulled. All attempts to figure out why this was happening failed. The bolt itself was more than wide enough to accomodate the strut, yet somehow it was catching. Even with the upper receiver completely off the gun, it still did it with this strut. The new and old struts were carefully compared and no notable differences could be found. Finally, out of desperation, I knocked out the pins and put the old strut on the new mainspring housing, and the problem went away.
Upon reassembly, I noticed the safety was not holding itself in the up (safe) position anymore. It turns out the safety knob can actually rotate on the piece, and it had simply rotated so the ball bearing was no longer positioned correctly to support it. A quick twist with pliars put it back. This is something to watch out for in the future, as it can easily happen and seriously affect the safety of the gun.
Conclusions:
So, looking back, here are my main observations:
(1) Very little has changed between the Mark I and the Mark III, except for parts in the trigger assembly.
(2) The spring assemblies are NOT user-serviceable. Don't even try it.
(3) Several decades of tolerance differences can cause a major headache.
(4) Watch out for that safety. If it rotates it won't say in the up position reliably. Verify the ball bearing is in the correct position, and use pliars to rotate the knob if not.
(5) Ruger's customer service is great. They answered my questions on parts compatibility and then transferred me directly to their parts department. I ordered the parts direct from the factory, and they were even less expensive than listed on shopruger.com, and a lot cheaper than on other websites.
Tools used:
old ball peen hammer
old Millers Falls 1/32" punch
1/4" brass punch
wooden block
Leatherman Charge TI (diamond file and pliars)
And a whole lot of caffeine, patience, and cursing.
Last edited:
