No.4 MkI can be fired form half cock

Hello all, I'm after some help.

I've just purchased a No.4Mk1 after much searching. The rifle is in pretty good nick, functions and shoots exceptionally well.

After a good cleaning I was doing a function check and have noticed something strange. The half cock engages as it should, however once it is engaged the rifle can be fired with a pull of the trigger.

The first thought I had was that either the end of the sear was damaged or the half cock notch on the striker was damaged/sheared. However I have checked both of these things and they appear all correct.

I have noticed that the trigger is fairly light with a very short first stage compared to Enfields I have shot in the past. Is it possible that I have a worn out sear spring which is producing just enough up force for the sear to catch the half cock but not enough to properly engage it with the notch?

I'll post some pictures of the parts when I can.

Quote:

---

Originally Posted by Towarzysz_Beagle

After a good cleaning I was doing a function check and have noticed something strange. The half cock engages as it should, however once it is engaged the rifle can be fired with a pull of the trigger.

---

When you say "a good cleaning" did that involve disassembly ?

Quote:

---

Originally Posted by Alan de Enfield

When you say "a good cleaning" did that involve disassembly ?

---

No.

By good cleaning I meant, removed the bolt, removed the magazine, took forend off and gave it all a thorough cleaning removing all kinds of accumulated crud.

I did not disassemble the bolt past removing it from the rifle. Nor did I disassemble any part of the sear mechanism.

Edit: Just for clarity, I did not perform any function check on the half cock before this point. So this is the first time I've checked it's function. This issue could have existed before I picked up the rifle.

Quote:

---

Originally Posted by Towarzysz_Beagle

Hello all, I'm after some help.

I've just purchased a No.4Mk1 after much searching. The rifle is in pretty good nick, functions and shoots exceptionally well.

After a good cleaning I was doing a function check and have noticed something strange. The half cock engages as it should, however once it is engaged the rifle can be fired with a pull of the trigger.

The first thought I had was that either the end of the sear was damaged or the half cock notch on the striker was damaged/sheared. However I have checked both of these things and they appear all correct.

I have noticed that the trigger is fairly light with a very short first stage compared to Enfields I have shot in the past. Is it possible that I have a worn out sear spring which is producing just enough up force for the sear to catch the half cock but not enough to properly engage it with the notch?

I'll post some pictures of the parts when I can.

---

Some photos would help as some wartime production cocking pieces omitted half bent, but where usually replaced as deemed unsafe.

Did you remove the trigger guard? The king screw and sleeve bushing effects trigger setup.

Over tightening could have changed the trigger function possibly? Id certainly be looking at that if trigger guard was removed.

Thanks for the replies so far.

When I said it works as it should. I meant if from full cock you grasp the cocking piece pull the trigger to release it past the full bent, release the trigger and then let go of the cocking piece, the half cock catches it.

The half bent is definitely there and undamaged.

I did remove the trigger guard, but it's back on correctly, with the bushing in place and I don't think I over tightened it.

I'll get some photos up today.

I guess there could be any one of several things going on here. Being lazy, what I would do, is simply replace the coking piece. Chances are, for about $10. or so, the problem would be solved. The number of safety assemblies and cocking pieces that could be installed, and the combinations of correct and incorrect parts, is simply dizzying.

These articles by Peter Laidler may be of help to get your head around the mechanics of trigger setup;

https://www.milsurps.com/content.php...-Peter-Laidler)

Quote:

---

Originally Posted by Towarzysz_Beagle

No.

By good cleaning I meant, removed the bolt, removed the magazine, took forend off and gave it all a thorough cleaning removing all kinds of accumulated crud.

I did not disassemble the bolt past removing it from the rifle. Nor did I disassemble any part of the sear mechanism.

Edit: Just for clarity, I did not perform any function check on the half cock before this point. So this is the first time I've checked it's function. This issue could have existed before I picked up the rifle.

---

I would suggest that removing the forend counts as disassembly.

Everything is linked on the Enfield and moving one part can have a serious affect on the rest of the 'system'.

Removing the forend (did you do it correctly, or just, 'pull it off'), removing the trigger etc all affects the trigger 'group'.


I remember putting new (old) wood onto a No1 Mk3* Enfield and it would just not 'cock' something was wrong and interfering with the 'trigger group'.

These rifles are not plug & play and the worst thing seems to be that some folk just have to take them apart - and then say "it must have been like that before I started"

What's wrong with "if it 'aint broke don't try and fix it"

Quote:

---

Originally Posted by Alan de Enfield

I would suggest that removing the forend counts as disassembly.

Everything is linked on the Enfield and moving one part can have a serious affect on the rest of the 'system'.

Removing the forend (did you do it correctly, or just, 'pull it off'), removing the trigger etc all affects the trigger 'group'.


I remember putting new (old) wood onto a No1 Mk3* Enfield and it would just not 'cock' something was wrong and interfering with the 'trigger group'.

These rifles are not plug & play and the worst thing seems to be that some folk just have to take them apart - and then say "it must have been like that before I started"

What's wrong with "if it 'aint broke don't try and fix it"

---

The forend was removed correctly. Bands removed, upper hand guards removed, then king screw, then trigger guard screw, and then gently rocked off at the receiver end. Put back together in reverse.

I'm not a complete spud. I have owned and disassembled Enfield rifles for a solid 15 years now without ever causing damage or something like this to happen.

If I perform the test where you cock it, turn the safety on then slowly disengage the safety while repeatedly pulling the trigger to generate a slip and test the half cock it catches the sear in half cock as it should.

I've re-examined the half bent and there appears to be some very minor wear, perhaps this could be what is allowing it to slip out of the groove if the trigger is pulled?

If you have a "spare" sear, swap it in. If the "long arm" of the original sear is distorted, (bent), it may well be engaging the very end of the half-cock notch and this not locking up the bolt and trigger movement.

Swapping in an "unmolested" one is pretty easy, after removing fore-end first. You then have to attach the trigger-guard assembly in its correct location (sans wood, of course) and see what is happening.

Please keep us posted.

Quote:

---

Originally Posted by Bruce_in_Oz

If you have a "spare" sear, swap it in. If the "long arm" of the original sear is distorted, (bent), it may well be engaging the very end of the half-cock notch and this not locking up the bolt and trigger movement.

Swapping in an "unmolested" one is pretty easy, after removing fore-end first. You then have to attach the trigger-guard assembly in its correct location (sans wood, of course) and see what is happening.

Please keep us posted.

---

That's a good idea, I happen to have a box of spare parts, I'll see if there's a sear in there.

Quote:

---

Originally Posted by Bruce_in_Oz

If you have a "spare" sear, swap it in. If the "long arm" of the original sear is distorted, (bent), it may well be engaging the very end of the half-cock notch and this not locking up the bolt and trigger movement.

Swapping in an "unmolested" one is pretty easy, after removing fore-end first. You then have to attach the trigger-guard assembly in its correct location (sans wood, of course) and see what is happening.

Please keep us posted.

---

Late update, but you were spot on mate.

I took the forend off and attached the trigger guard and bushing. The sear is being caught by the half cock but not making it all the way into the notch.

The interesting part is that the original sear does not seem bent or damaged in any way. It engages properly with the bent, and disengages consistently when fired. It also engages correctly with the safety.

The rifle does have a non-matching bolt. Which bears well on both recoil lugs (first thing I checked on the rifle). I'm guessing this issue with the half cock is a matter of fit, and I am unsure how to correct it.

Just wondering: Has it ever been a "Range" rifle?

Folks used to do some "unusual" things to their target Lee Enfields; some of them extremely dangerous. Triggers, sears and cocking-pieces got all manner of "tuning" done to them. Bolt bodies as well; really quite scarey...

Heard of "psycho-acoustics"? I am fairly convinced there is a school of "psycho-ballistics" as well.

Quote:

---

Originally Posted by Bruce_in_Oz

Just wondering: Has it ever been a "Range" rifle?

Folks used to do some "unusual" things to their target Lee Enfields; some of them extremely dangerous. Triggers, sears and cocking-pieces got all manner of "tuning" done to them. Bolt bodies as well; really quite scarey...

Heard of "psycho-acoustics"? I am fairly convinced there is a school of "psycho-ballistics" as well.

---

Oh I'm no stranger to this. I've spent a lot of time shooting and collecting Enfields. I have come across some pretty crazy bubba examples in this time.

Like a trigger where the humps had been so haphazardly ground down to create a single stage, that the end result was the sear protrusion into the bolt channel being inconsistent and not always catching the bent. Couple this with when it did catch its position was so low on the bent that if you gave the ground a tap with the but it would release as if the trigger had been pulled. That was extremely dangerous obviously but also easily fixed with a new trigger.

I've also come across ground down bents as well which again interfered with the consistency and safety of its engagement with the sear.

So yeah I have a fair idea of what to look for with some of the dodgier things people do and this rifle doesn't exhibit any symptoms of tampering/grinding etc on the bolt, sear or cocking piece.

It's really got me scratching my head.

If somebody stoned the bent on cocking piece, the very edge, from which the sear trips, will have changed position.

The metal has a sloping surface behind the bent where it is cut for the half cock notch. If you remove metal from that face, you will start moving up that ramp with the edge. The end result is that the height changes. If stoned enough, the tip of the sear when it trips is no longer at a height to clear the half bent and will catch on the half cock, either hanging up, or causing the striker bump and to slow down, resulting in a light primer strike.
Usually discovered when squeezing the trigger very slowly to release. Cant tell by a quick function check. A tug on the trigger, everything still works as it should. A squeeze, it can jump into half cock, or in this case, hang on the edge..

Often seen on Farmer Brown trigger jobs, his solution would be to file a bevel on the underside of the cocking piece at the half bent to allow the sear to slide past.

It gets worse as Bubba tries to fine tune it with file and stone.

No fix for this other than replacement. On inspection, if I see file and stone marks on the cocking piece, it gets switched out. No point in trying to fix.

Perhaps this is not the exact situation here, but it is all related. The trigger group is a tuned system. Adjust one thing and you screw up another.

My thoughts are to simply change out the cocking piece with a known good one and maybe the sear, that should certainly fix the problem.