DIY Mark III mag safety removal spacer washers

[Bullseye]

Here's how to make your own magazine safety spacer washers to remove that pesky magazine disconnect safety from a Mark III pistol. I have used common tools found in most home workshops for this modification. No lathes or mills were used to make these spacers.

Tools: 1 pr large wire cutters (dike pliers)
1 fine bastard file
1 #2 Phillips head screwdriver
1 Meduim adjustable (Crescent) wrench
1 Drill press ( hand drill mounted carefully in a vise will work)
1 bench vise
1 Sharpie brand permanent marker

Materials: 2 #10 SAE flat washers $.06 ea. from local hardware store
1 Stainless countersunk machine screw
1 machine nut with integral star lock washer

Two SAE #10 flat washers will do the trick. You can use steel or stainless. Disassemble your Mark III pistol and remove the magazine disconnector safety spring and the disconnector hook off of the hammer bushing pin.



The washers will not work without some fitting. The inner washer will first need a flat spot, about 1/16" deep, cut out of the circumference to fit into the hammer cut out. This first cut will keep the lower washer in place, providing the necessary index spacing for the rest of the cuts on this washer. I used the wire cutters to make this cut, then smoothed it up with the file.



There will be two more cuts made to this inner washer. The second cut will be the most critical. It is there to provide clearance for the sear face and the hammer hook. Line up the inner washer based on the first cut. Then draw an approximately 3/16” line across the bottom of the washer for the sear clearance. Now make the angled cut with the wire cutters on the washer and then check for clearance with the hammer and the bushing pin. You should be able to see the entire hook under the washer. If the cut is not deep enough, then use a file to deepen it in a vise and recheck clearance. The third cut is one to dress the washer with the front face of the hammer. Draw a line and make the cut with the wire cutters. This cut should be flush or slightly lower than the hammer’s front face. Dress all cuts with a file and deburr them as necessary. See picture below.



Now you must reduce the outer diameter of the second washer from 1/2" to 7/16”. This will provide the proper clearance for the sear face to reach the hammer hook when the entire assembly is put together. You can make a holding jig using a countersunk machine screw and a locking nut to hold it tight. Place the jig in a drill press and use a bastard file to reduce the outer diameter to 7/16". Deburr the washer afterwards for smooth operation in the pistol.





Install the entire assembly and check for clearance between the sear and hammer. Do this check with the receiver off the pistol, just in case there is a clearance issue. Use your thumb to catch the hammer when it is released by the sear. Once you are sure that the clearances are done, you are now ready to reassemble the pistol sans the magazine disconnector safety.

Hope this helps.

R,
Bullseye

[N6CRV]

Hello Bullseye, I tried to remove the magazine safety as showned. I went with a brass washer for the first one and a steel one for the second as they seen to fit the best and the brass was real easy to shape. How close does the second one need to be to the 7/16? I know mine was smaller then that but I had good clearance for the sear and hammer. When I reassemble the pistol the hammer would not drop the trigger did nothing. Had to get the sear to release with using a pick. So then even tried a washer on both sides of the hammer same trouble. I put the stock parts back in and it works fine. I have to be doing something wrong. Any thought would be a big help. Thanks
Don

[Bullseye]

This sounds like a problem I could see easier in person better than attempting to visualize in my mind. My first instinct is that one of your washers is blocking the sear's movement in some way. This could be by physically stopping the sear, or interferring with the disconnector lever and preventing the trigger from activating it.

Your outer washer can be a little smaller than 7/16". The key with that washer's size is that it won't slip inside the disconnector's hole and interfere with the movement of the disconnector. That could be what is happening with your movement problem.

The best way to observe what is happening is to work the trigger with the receiver off the frame and use your thumb to catch the hammer as it releases. This is a great way to learn how the pistol's components interact with each other.

Hope this helps.

R,
Bullseye

[N6CRV]

Hello, I bet you are right the outer washer is getting stucked in the disconnector's hole. Will try it again. So far been having fun. Thanks for the help.
Don

[Rev]

Yup, I had to make my outer washer about 3/8" or a little less instead of the recommended 7/16" in order not to hold the sear out of engagement. The mod worked well though when I got that done. Thanks to Bullseye for this innovative and inexpensive solution to the magazine disconnect safety feature. My pistol did have a somewhat different looking mag safety disconnect lever than the one pictured in the break down instructions (maybe a later Mk III). Anyway, it worked perfectly and I owe that success to Bullseye.

Rev

[stalkingbear]

Another tip is to simply use an mk2 hammer such as those from Volquartson or Power custom and an mk2 hammer bushing-LOTS faster if you have to do several of them and are leery about honing the factory hammer (for reduced pull weight)in fear of going too far. Personally I use Ruger mk2 hammers and stone then as necessary.

[marlin1881]

Bullseye, Thanks for the pics and tips on how to remove the mag safety. This works well.

I do have a question for you though. I also polished up the sear and hammer hook, and reduced the sear engagement to .020" for shooting in Bullseye competition. I also added a reset travel screw, and adjusted the overtravel as well. Nice trigger, with minimal overtravel and reset. As I suspected, this did alter the operation of the safety, as with the tolerances very tight, the gun will now fire with the safety ON.

Do you have any ideas on how to tighten the tolerances of the gap on the safety lever hook that goes over the sear?

Thanks,

Marlin

[bearandoldman]

Sure am glad my pistols are all II series and do not have to mess with all that stufff, removinng non required so called safety features. The real safety is in the operator control computer.

[Bullseye]

Do you have any ideas on how to tighten the tolerances of the gap on the safety lever hook that goes over the sear?

Thanks,

Marlin

You have an unsafe pistol. Do not operate it in this condition.

What kind of equipment do you have available? I would TIG and recut the notch in the safety lever for your engagement. Otherwise you may have to get a new hammer, sear, or both and start over.

R,
Bullseye

[marlin1881]

I've got access to a TIG welder, so I'll build up the safety notch and re-cut. It didn't surprise me that this might happen, as the factory tolerances allow for some "slop" in the action parts. When those tolerances are minimized, then the "slop" can be too much for other parts to handle properly. I'll let you all know what I came up with. Thanks.

Marlin

[Bullseye]

That will do the trick. You are right about the factory tolerance on the safety hook. Once you reduced the hook height that allowed enough clearance for the sear to release the hammer within the safety hook's factory gap. You'll likely just need to add a little material to the outside of the hook to prevent premature release. That is why I asked about your equipment access, not everyone has a TIG handy.

R,
Bullseye

[marlin1881]

Trigger systems are interesting pieces of mechanics, and I've rebuilt many different kinds, with varied results. I put a match trigger kit in a Springfield XDM, and reduced the sear engagement to .040", and it bench-tested just fine. Then I did the pencil test (pencil with eraser against the firing pin hole), dry-fired the gun, and the pencil didn't move. The disconnector was now not raising enough to release the firing pin block. Some machining there, and it was good as new. Granted, not a "match-grade" trigger, but MUCH better than factory. Ruger single-actions are probably my favorite, as they tune so nicely. I also now know where a 1911 can become un-reliable, as less than a 2 lb trigger, and you CAN get the gun to go full-auto on you. That will open your eyes . My bullseye 1911 is set exactly on 3.5 lbs, and it shoots very well.

On the MKIII that I'm building now, I'd like to get the trigger to exactly 2.5 lbs to be legal for bullseye. This gun is a 5.5" slab-sided bull barrel, and I'd like to see what it does for my scores. I'm working on the theory that a shorter barrel (my other gun is 6-7/8") will have less dwell time, which MIGHT lead to less wobble-effect. Even if it's only in my head, but if my scores get better, then some progress will have been made.

This MKIII is the tightest gun I've ever owned, as it does take a mallet to get the receiver off the gripframe. I used to own a 22/45 5.5" bull gun, and I had to shim it to keep the receiver from floppin' around. Strangely loose gun. I never did any trigger work to it, as it just didn't seem to have the potential I was looking for.

I'll keep you informed as to how this gun turns out. It's got potential, as I can see a 6-pointed carbon "star" on the muzzle after a shooting session. It looks like the bullet releases very evenly at the muzzle.

Marlin

[ruger22]

I just finished making a LCI plug out of stainless , and posted a reply there about it. Now I'm planning this mag safety mod. I learned something getting the materials.

A stainless number 10 washer is smaller in diameter, 7/16 versus 1/2 in steel. This will help in making the second washer, it may fit fine as is. But a stainless number 10 is also only two-thirds as thick as a steel one, so it takes three to equal two steel ones in thickness.

I also notice in looking down in the frame, that the first washer only replaces the coil in the mag safety spring. So I don't see a need to make the three cuts that match the hammer shape. A stainless M5 (metric) washer is a lot smaller than a number 10, with the same size hole, give or take a few thousandths. So I'm thinking it may replace that spring coil just fine as is. If I really need to start with a 1/2 inch number ten, then that takes a stainless number 10 fender washer, which is over a half inch in diameter, and it will need to be reduced. But the fender washer is the same thickness as a steel number 10.

Now the question will be, if if takes three stainless washers to fill the same space as the two steel ones, do I use two M5 and one number 10, or vicey-versy? Or some other combination? Somewhere in my assortment of washers, I'll figure out my answer, and post the results.

[ruger22]

Okay, I'm done with the mag safety washers, and the winners are......

A M5 stainless washer against the hammer replaces the spring, and just does clear the hook on the hammer; two number 10 stainless washers next, replacing the mag safety arm. The only modification, I had to slightly enlarge all three washer holes with a round needle file.

Actually, two M5 against the hammer, then one number 10 would probably work as well. This since the main thing is to have a 7/16 washer that won't catch in the trigger disconnect hole. It all depends on your exact washers and preference.

I was surprised that the stainless number 10's had a smaller hole than a regular steel number 10. I would have thought those holes would have matched. A different manufacturer might match better?

Everything seems to function okay in the gripframe, so I'm optimistic it will be fine fully assembled at the range.

I've sent photos to Bullseye, not much different than the original project posted above. He may post them if I sent them correctly where he can use them.

<<EDIT- Here's the pictures>>

[ruger22]

Thanks for the photo post, Bullseye. They look better than I thought they would. I had no intention of horning in your DIY, just had an alternative since the stainless hardware measures a bit differently.