Making a Mule Ear Lock

[dd832]

This build will scratch build a mule ear lock and use a coil spring mainspring and sear spring. I believe that the L&R mule ear lock is the only one commercially available right now and the Pioneer M.E. I think is not made anymore, so anyway I want to make one that is a little different from those two locks. I have incorporated some ideas from older commercial and one-off made locks into this mule ear.
Here's a Tingle ME lock from the '60s:

Here's a Pioneer lock:

Here's an L&R ME:

And finally a lock made by John Taylor:

My mule ear lock will be most similar to the Pioneer Arms and the John Taylor locks.
Mike

 

[dd832]

So here are some photos of the beginning of this build. The first is the material I used to make the lock, a piece of steel found along the roadside while doing construction:


This was a piece of 1/2" steel shaped into an "S". The lock plate blank is at the bottom. Pay no attention to the date, darn camera default setting.

Next is the lock plate interior roughed out and trimmed somewhat:

Next is the beginning of the hammer, sear and an aluminum disk (5/8" diameter) used to fit the hammer slot in the lock plate.

The hammer pin is 1/8" dia. and the sear pin is 3/32" dia.
Mike

 

[dd832]

I always liked the look of the hammer on the Jenks carbine, so I'll be using that style on the build. Here's an early Jenks carbine that has the straight thumb piece & not the curve thumb piece of the later hammer:


Here's a photo of the hammer as of today, there's still some minor shaping to come:


Here's a top photo:

 

[dd832]

Here's the interior of the lock:

You can see that the lock has two sears. The main sear engages the 1/2 cock and full cock on the hammer. The secondary sear pushes against the main sear tail, so you can use a conventional style trigger. There is a small coil spring under the main sear.

Here's a shot of the lock at 1/2 cock:


And full cock:


Mike

 

[dd832]

Here's what the trimmed lock looked like yesterday:

The lockplate is 3-15/16" long and about 0.90" tall.

I put the lock against a rifle plan and decided the rear of the lock was too long, so I cut off the 2 mounting blocks for the second sear and made a replacement tab to insert into the lockplate. I cut a slot in the plate and nailed the tab through and it looks like this now:

The camera wasn't working so I don't have photos of how I installed the tab through the plate, but this photo is similar from when I made a wheel lock:


After you get the tab through the plate, you peen the metal over like this:

Then you mill off the excess tab, draw file and wet & dry sandpaper it comes out like this:

Mike

 

[dd832]

So now the lockplate is 3-9/16" long, trimmed down from 3-15/16" and it looks like this:

One of the mistakes I made in the design, is that the hammer is too high on the lockplate and on the interior it will rub against the barrel. So I had to bevel the top of the sear and a portion of the hammer to make it so it didn't touch the side of the barrel.

I'm thinking of using this lock on a target pistol similar to this one made by the late David Brooks:

My lock would be on the left side of the pistol - a mirror image of this. Mike

 

[okawbow]

Looks really good! Should be fast.
Here is the one I made for my chunk gun. Patterned after an original Morrison.

 

[dd832]

Looks really good! Should be fast.
Here is the one I made for my chunk gun. Patterned after an original Morrison.

Hi okawbow, I've seen pictures of your chunk gun & mule ear with the outside mainspring posts. How do you like that lock? Looks powerful.

I saw a pistol on a recent auction made by the late Alvin White (noted engraver) that had an outside mainspring but appeared to use a conventional sear off the hammer.

Looks like a cool lock to copy and it will have a 1/2 & full cock to boot.

 

[okawbow]

That lock works very well for use on my chunk gun. It doesn’t have a half cock. Doesn’t need one on a 22# target rifle. I have the spring set loose enough to lift the hammer and put the cap on without cocking the lock. I never cap the gun anyway until it is on the chunk and pointed down range. The lock time is very fast with the stiff mainspring, and the direct ignition path to the powder makes for instant, sure fire ignition every time. Very important in a chunk rifle. It’s also very easy to fix in case the mainspring breaks. Never has, but I carry a spare.

 

[Metalshaper]

Three of mine! Back Action, my outside mainspring version and the Medberry pattern is laying in the background..

Respect Always
Metalshaper/Jonathan

 

[Metalshaper]

dd832,

Apologies on my part..

got excited seeing another Muley Maker..

Respect Always
Metalshaper/Jonathan

 

[dd832]

dd832,
Apologies on my part.. got excited seeing another Muley Maker..
Respect Always
Metalshaper/Jonathan

Jonathan, no apologies needed here - I'm glad you chimed in on the mule ear locks!

I've started a 90% look-a-like version of the Jenks mule ear carbine lock and will be posting it here later. I say "look-a-like" because the interior will not use the same layout of the Jenks, but a more conventional layout with a flat steel spring and a stirrup to the hammer. Somewhere long ago I had read that the Jenks lock was 6-5/8" long, but I'm not sure that is the case, because in November '18 a member posted photos of his "new" Jenks carbine on a grid board and the lock appears to be 7-1/4" long. Anyway, my lock will be about 5-15/16" long IF I finish it. Right now the lock has me in a headlock and I my not win. Mike

 

[Metalshaper]

Mike,

I have the start of a Jenks lock on my bench. Took my measurements from the book that shows various CW carbines as measured drawings.. also have the start to a Jenks action as well

Some day I'll get it done..

Respect Always Metalshaper / Jonathan

 

[BillinOregon]

This four-plus year-old thread is worth bumping. Nice workmanship, fellas.

 

[tom in nc]

Another bump. Some of the best mule ear info I've found.