Miroku MLR trigger

[B4408]

I know there are a few of you with MLRs or BLRs so thought this might be of interest and you may have some ideas.

I have gradually been doing a restoration of my MLR 243. We have had it since new in 1977 when it cost $239.20, found the docket with the instruction book. It has fired about 600 rounds but spent a lot of time sitting in the 4wd when we had the farm, so it was a work rifle and shows it. I have taken wild dogs, scrub bulls, crows, rabbits, goats, pigs and put down a few cattle during the drought with it, so an all rounder. It always wore a Leupold VXII 2-7 scope until recently.

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1977 MLR 243

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So I refinished the stock about 18months ago by stripping off the gloss plastic coating, gave it a coat of walnut stain and rubbed in lots of coats of Feast Watson Fine Buffing Oil and then took the shine off with steel wool.
When doing the forearm it showed lots of rubbing on the barrel and barrel band. It had never been a consistent shooter especially with a warm barrel. So I free floated the barrel by bedding the forearm hanger and cut the barrel band where it wraps over the barrel. Well that turned it into a consistent shooter, not moa but 1.5 at best and around the 2-2.5 regularly held point of aim when hot. The inside of the barrel is very ordinary... so not expecting to much.

Now the trigger is the one thing you will here criticised about these rifles(BLR are same). So I have always just used it. It is like a two stage with the last stage a heavy 3kg(6lb 10oz) but no creep. The first stage is unavoidable due to the lever linkage setup.
Searching the web there seems to be no info on how to tune the trigger and comments that it is major job to pull the bolt out and retime it on installation due to the gear drive. There is mention of a few gunsmiths doing trigger jobs. Well I thought it must be possible. So yesterday I sat and looked at it trying to work out a system for marking the gears etc. Then realised that the sear and hammer are not connected to the lever and you only need to knock out two pins to get them out and then I would be able to see why the sear is so heavy.
Steps
1: remove but stock
2: Remove mainspring tube and spring, this powers the hammer. I had to heat it with the soldering iron to release the glue where it is threaded into the frame.

Mainspring tube

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3: Drive sear pin out . It was not tight. Catch the sear spring when it releases.

pins to remove

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sear, sear pin and spring

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4: Drive Hammer pin out from left to right, it has a spline on right side. The hammer will lift out through top.

hammer and pin, note spline on pin

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So here are some pics to show the parts and it may help someone else fix a heavy trigger on there MLR/BLR. The main point is that you do not have to strip the whole action to get at the trigger as most info indicates.

regards
Bruce

more to follow.

[Camel]

Good onya Bruce, they are an interesting rifle, will be good to see what kind of trigger you end up with.

[B4408]

You can now see the sear and hammer engagement. I made a jig to hold them in position so I could see how they engaged. There is probably a bit more sear engagement than it shows due to the jig.

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sear & hammer

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sear & hammer

sear

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sear and hammer

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Now for my rifle the problem seems to be that the sears hook together when engaged, the faces are opposed angles not flat surfaces. So to release it is not only the sear spring but also pushing the hammer against its spring. There is very little sear travel.
The big question is how am I going to reshape the sear?

I am thinking of ever so slightly flattening the sear face ( take the hook off and keep it flat etc). Not sure how yet . But will keep looking for better ideas. I can increase sear engagement if needed by filing the sear where it rides on the hammer.
Wanting some suggestions,
I may even leave it alone....

regards
Bruce

[B4408]

Camel , your to quick. At least its not a 6.5.........6.71..........................yet. If I can improve a few things it may be worth rebarreling.
Bruce

[MISSED]

I think you are on the money Bruce.
It looks like for the sear to disengage it needs to lift the hammer (compress hammer spring).
Not sure how you are going to get around it apart from a tig ,mill and stone.

[Camel]

A smooth diamond lap may be the go to get the sear nice and flat mate. Can you replace the sear spring with a lighter one, that may work.

[morerams]

You're thinking on the right track, polish/smooth the hammer contact change the angle little or not at all, carefully change the angle on the sear, go slowly and keep trying to see how you are going, too much & it wont stay cocked.
Don't change the sear spring and make sure it goes back in the right place when reassembling.
You should be able to get pressure down around 3 to 31/2 lbs before you start on the trigger springs.
Reduce the spring pressures on the trigger and connector until they are about 1lb then you can usually get the overall pressure close to 2lbs when you get the sear right.

[B4408]

Camel, I will look at the diamond hones may have other uses as well.

Morerams, that is what I was thinking. If I could get to under 3lbs would be happy. Have you had experience with these triggers or talking triggers in general? What do you use to hone/polish?

I am going to have another go at redoing the jig, think it is not quite right and found a better drill bit.
Bruce

[morerams]

I have done several Miroku/Brownings this way and use a combination of diamond & ceramic hones. You already have the holes in the action to see how things line up, no need to make a jig.

[stinkitup]

Any pics or details on good hones for triggers.

[B4408]

Any pics or details on good hones for triggers.

+1

[kickinback]

I will post up what I have when I get home.