PDA

View Full Version : Winchester Short Rifle 20" .357 Miroku 1873 Trigger Safety Spring



Liberty1776
05-02-2019, 10:10 PM
As you may know, the Winchester 1873 Uberti / Cimarron made in Italy, and the "official" Winchester / Olin Corp 1873 made in Japan by Miroku are different is some ways.

One difference is the trigger spring and the trigger safety spring in the two rifles.

In the Uberti 1873, the springs are two, separate, flat leaf springs.

In the Miroku 1873, the spring is a one-piece coiled wire spring.

I wanted to lessen the Miroku's trigger safety spring tension so I didn't have to squeeze the finger lever against the stock so forcefully to allow the gun to fire.

I called both https://www.pioneergunworks.com/ and Shotgun Boogie Gun Works https://www.facebook.com/sbgwllc/. They both supply reduced-tension springs for 1873's.

But when I asked them if their springs worked in the Miroku, both said, "No. The rifles are different."

Trying to locate an exploded schematic for the Miroku is almost impossible. The owner's manual says, "Don't take the rifle apart. Go to a gunsmith." No diagram in the manual. So I had to take the rifle apart to see how it's set up inside.

Here's a side view and an internal view of the trigger group removed from my 20" short rifle .357 Mag Winchester Miroku. The photos are large, but that allows detail to be seen.

241015

241016

Note how thick the coil wire spring is and how its left prong wraps around and pushes down on the silver bar (the trigger safety bar) while its right prong reaches forward and supplies tension to the trigger.

This is the exploded schematic for the Uberti. Note the flat springs.

240973
240974

I'm posting this mostly for general information. Parts for the Miroku are almost non-existent.

The Miroku is a beautiful, finely made rifle. But if you want to modify the rifle for Cowboy Acton Shooting, get a Uberti. Parts are much easier to come by.

I could mess with the Miroku spring to make it lighter, but if I screw it up, I don't know if I could get a factory replacement. So for now, I'm leaving the gun alone and shooting it factory.

The problem is, when shooting rapidly, the finger lever simply does not push up on the trigger safety easily and blocks the trigger from being pulled. I pull the trigger and it won't fire. I remember to push up on the lever and it allows the trigger to be pulled, and then fires. Oh, well.

If anyone here knows how to lighten that spring or has a source for a lighter spring, I'm all ears.

Thanks.

Bazoo
05-03-2019, 02:33 AM
If it were me, I'd bend the spring so it had less downward tension. Bend it in place.

Liberty1776
05-03-2019, 11:22 AM
It's a plan. Doing it in place would help, too. Just have to make a small tool with a groove in it that can go around the spring so I can bend the spring up just a bit.

1911aug
05-04-2019, 09:57 AM
I have one in 45 colt and I did what Bazoo suggested. It has worked fine. I shoot with my thumb along side the stock instead of wrapped around the tang.

Liberty1776
05-04-2019, 01:37 PM
Your shooting technique is what I want to use -- right thumb pivoting against the right side of the rifle as the finger lever is operated -- not reaching my thumb over the stock between shots.

But that stiff safety bar spring often stops the lever from fully going up against the stock and thus engages the trigger safety, slowing me up.

Our fastest shooter in our local CAS club points out that the safety spring on his Uberti is so light he can push it in with hardly any effort.

One thing he definitely said NOT to do, is to remove the safety bar. Apparently some have done this.

Removing the safety bar can allow the trigger to be pulled before the toggles lock up inside. This could allow the bolt to fly back into your face. Not good.

Bazoo
05-04-2019, 04:26 PM
Looks like to me you could come from the side put the tip of a flat point screwdriver under the spring and pry it up. Maybe then grab it with needle nose pliers, again from the side and have no trouble bending it.

Randy Bohannon
05-04-2019, 09:44 PM
I spent $310.00 and my gunsmith friend did two Win/Miroku 1873’s and did an amazing job on the trigger and the lever spring. www.sprincreekarmory.com top notch gunsmith. He’s local by Wyoming standards 60 miles one way. Bill is worth every penny and effort. He showed me what he did polishing and stretching some parts. But I just don’t care to know how to do this quality of workmanship.

Liberty1776
05-04-2019, 11:57 PM
Link is missing the "g." It's www.springcreekarmory.com

Thanks.

JLynch
12-07-2021, 08:54 PM
There is now an aftermarket / replacement trigger spring for the Miroku Winchester 1866 and 1873 rifles from Slixprings. It's the same basic shape and size but made from a smaller wire diameter yet more durable steel. It takes only minor fitting on the end which provides trigger / sear tension.

https://www.slixprings.com/proddetail.php?prod=Miroku-Firing-Pin-Trigger-Safety-Sprin (https://www.slixprings.com/proddetail.php?prod=Miroku-Firing-Pin-Trigger-Safety-Spring)g

292795