irregular trigger pull off on a n°4 MkI

[Lou Cypher]

Gentlemen,
I need your experience to fix a problem that I get on my new n°4 MkI born in Shirley in 1944.
To make it short, when the rifle is in one piece, I don't get the 2 PO. I squeeze only once before the release of the cocking piece even if I'm very careful and using an other finger then the index.
When the forend is disassembled, I get the 2 PO as desired.
I checked the sear, the cocking piece, the trigger, they are all good.
Nowhere it's mentioned that I could get a different reaction of the trigger with or without the forend. The pull up pressure at the muzzle is at 7.1 lbs, could it interfere because it is at the top of the limits?
When I fit the bolt on my other n°4 MkI, I get the 2 PO.
What's wrong?
Thanks

Lou

Information

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[Peter Laidler]

The fore-end is affecting the pull off. Fit the fore-end correctly and make sure that the fore-end collar is the correct length. Only when all of this is correct can you start to adjust the trigger bents to get the correct pull-off

[Ridolpho]

Lou: In the relatively short time I've been collecting and shooting Lee Enfields I've run into a few where the forend was obviously an off the shelf replacement shoehorned onto the rifle by someone with no knowledge of how it should be done. The material is all here on this forum to troubleshoot your rifle and fix that trigger pull. Be very patient and study everything Capt. Laidler and others have posted on the subject of forend fitment and you will sort it out. You could try installing the forend without the collar to see if that affects the trigger pull and then check out threads about how to adjust collar length if that seems to make a difference. in any case, what better to be doing over the Christmas holiday than working on your No. 4.

Ridolpho

[Son]

Hi Lou.
As luck would have it, I have already done some pics to help another group understand the relationship between the trigger and the sear.
Your problem would seem to be with the trigger guard's fit to the foreend, as it works with the foreend off (I assume the trigger guard is installed with the steel collar under the front, but without the foreend).
As mentioned above, Peter's lessons on fitting the foreend are the go text for what you need to do, but here is what you have to achieve- (pics are a No1 rifle, but they are essentially the same)

Pic 1 the trigger is just being depressed and has come into contact with the sear on the trigger's bottom lug.
Attachment 68115

Next, as the trigger is pulled the top lug takes over contact with the sear.... being further away from the axis adds weight to the effort needed.
Attachment 68116

Looking at the sear on the bent at the first pressure you can see the contact is high up the face.
Attachment 68117

And at the second trigger pressure the contact is lower, almost off the face.
Attachment 68118

And after firing, the trigger is right back and the sear is well below having released the cocking piece.
Attachment 68119

You may be able to use this info to decide if the trigger is releasing on the first pull or not contacting it at all, and just contacting all the way on the second pull.

[Peter Laidler]

All should be advised that some publications suggest the way to cure and/or adjust trigger pull is to bend the trigger guard to suit. In my view and opinion, I have never read such a load of old absolute bolloxxx in my life. The trigger guard must be flat to start with and the pull-offs adjusted using the rounded bents with a triangular shaped stone. So fit the fore-end and collar properly first followed by setting the trigger pull-offs and weight

[Son]

All should be advised that some publications suggest the way to cure and/or adjust trigger pull is to bend the trigger guard to suit. In my view and opinion, I have never read such a load of old absolute bolloxxx in my life. The trigger guard must be flat to start with and the pull-offs adjusted using the rounded bents with a triangular shaped stone. So fit the fore-end and collar properly first followed by setting the trigger pull-offs and weight

On the few occasions I have had similar problems with a No1 rifle, I was lucky enough to have a variety of triggers to call on. Once I know which of the two lugs is doing all the work I put that trigger on a trigger pivot pin and one at a time put the spare triggers on the pin to compare the profile. Most of the time I have found one that fixes the problem, but a couple of times I have started with the most suitable and stoned the contacting lug down to achieve the two stage trigger.

[Peter Laidler]

Same as us at our workshops Son. We had a tray of triggers, sears and cocking pieces - and all the mechanical parts - and you could usually set them up by interchanging with part worn serviceable items. But as apprentices in the classroom, it was all done by accurate hand fitting

[Lou Cypher]

Thank you for your advises. So,
I read the thread "fitting a forend" I didn't read that one carefully before, because I trusted the woman or man who fitted the forend 71 years ago, yes I'm quite sure that this rifle has never been trough any repair facility, anyway, I checked the trigger guard
Attachment 68126
It looks correct, and of course, it's flat, not bent
The trigger has 2 good ribs hasn't it?
Attachment 68125
The collar is 0.5" long, when I tighten the trigger guard to the forend without the collar, I need 5.8 turns, 5.7 with the collar set in place.
When the forend is fitted, the barrel is centered at least to me, the gauges tell me the same.
Attachment 68123
The rear lugs are bearing evenly.
When the forend is not fitted, I can see the same thing than on the Son's pictures, but as soon as the forend is in place, I feel like after the first rib, the nose of the sear is already at the place where it should be after reaching the second rib, am I understandable?
I put a piece of cork under the reinforce bearing and the result is a really sensible trigger pull, as if the sear was already at the lowest place on the cocking piece ready to release the pin and this before any action on the trigger
In that case, I wonder if the rear side, circled in yellow on the picture is not to high.
Attachment 68124
If I consider the trigger guard screw as a pivot, it would explain the high muzzle pressure that I get, 7.1 lbs.
Should I use sand paper to remove wood from that part?
But in that case, it means that the flat surface that I have won't be flat anymore.

What should I do?

Lou

[Peter Laidler]

IF the fore-end is fitting perfectly along the body ledge, the drawers and the breech - and the muzzle pressure is excessive then you 'float' it out using a rounded float file that Armourers have in their tool boxes. A bit at a time until the load comes down. You MUST correct this before you start to correct the trigger pull-off

Only when this is correct can you start to adjust the trigger pull-off. But before you do make sure that the bolt is a good fit in the body and that the cocking piece is a tight fit on the striker

[Lou Cypher]

Thank you Mr Laidler,
By float it out, you mean " to file"?
I disassembled again and again, and I more likely get this result on the trigger guard than the one showed before.
Attachment 68128
It seems that the angle of the trigger on the sear changes. This is the second rib which is in contact with the sear. When I pull the trigger, the cocking piece goes less backward than when I feel the 2 PO.

So this is Christmas, and I have time to solve my problem