Quick question about reduced bolt lug on a No1Mk3

[louthepou]

I did bump into something that got me wondering, and I thought I should ask about it.

A No1Mk3* came to my place recently. Close inspection, revealed that - from what I can understand - for some reason someone took one of the locking lugs to the grinding stone. I noticed this because it wasn't showing the same rounded profile than what I'm used to see.

The bottom / left side lug of the bolt is slighlty less tall than others I compared it with; I didn't precisely measure it, but it looks like maybe 1/32nd or 1/16th of an inch was removed.

I am not sure what that was done, but more importantely can it weaken the whole assembly, since technically, there is less metal contacting the action and transfering the force when a shot is fired?

Thanks for any tip,

Lou

Information

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[krinko]

The only reason to grind the lug is to prevent it snagging the sear lever as the bolt is closed.
There is always a measure of vertical play when the bolt is open---closing the bolt normally puts downward pressure on the bolt body, pushing the bottom lug lower in the track. If an action body is worn, or sprung, the bottom lug will smack the sear lever as the bolt is pushed forward, giving out an audible click.
Stick an unmodified bolt in it and see if it clicks.
-----krinko

Please change "The only reason..." to "A main reason..."

[Alfred]

The left lug of some drill rifles imported from egypt are ground down abit. These rifles have the left locking recess partly filled with a welded in rod to prevent use of a bolt not modified for the purpose.
The bolt heads were welded but the barrels and chambers were left unplugged.

[SpikeDD]

I have run into another reason.

Depending on how much your lug has been ground, it may have been done so as a little talked about "DP" modification. In the lug channel in the bottom of the receiver a 1/8th? hole is drilled all the way through. A small steel "block" with a stud is fitted into the channel and the small bolt lug is ground down about half way to pass over the "block". The handful of rifles I have seen with this modification are not in any way marked as such, other than "DP". A VERY dangerous situation for someone looking to shoot a "DP" rifle, not knowing to check for this particular mod.

Below is a pic of the "block" having been removed but the stud remaining. At least is shows the area to check for these "blocks". This rifle, and another modded in the same manner, were purchased by me over 9 years ago from one of our favorite auction sellers as a "MINTY", "NO ADDITIONAL PICTURES PROVIDED, NO EXCEPTIONS", "I DON'T SELL SHOOTERS", example of a WWI NO.1 MK.III. You will note in the first pic the damage caused by a slipped chisel forward of the remaining "stud". A true butcher.

Just something to be aware of. These two examples are of British manufacture.

[Alfred]

Very good photos, and a good idea making these available.

I have suspected that an out of spec Lithgow action I have may be a reactivated Drill rifle of some sort. Its a Lithgow and all the Egyptian Drill Rifles with these modifications I've seen adverted are also Lithgows. They seem to be all pre WW2 though, while mine is late WW2 manufacture.

Some altered Drill rifles were sold here years ago for $25 to be stripped for usable parts. Could be some of the altered bolts have ended up being sold as replacement parts.

[Edward Horton]

Lou

Look on page 42 or 3-2-28 (manual page number) of the Canadian No.4 manual below:

http://photos.imageevent.com/badgerd.../No4Mk1Arm.pdf

You will see that you are to stake the receiver to lower the sear to keep it from hitting the locking lug. Only a Bubba or a (expletive deleted) would grind the locking lug down to make clearance.

The manual also states that “both” locking lugs should be making equal contact with the receiver lug areas, (no percentages of contact given) so just make sure you have enough “meat” left on the lug to ensure proper support.

And to think it was only yesterday I watched a Red Green episode where they cut the roof off a K-car and made it into a convertible and only used two rolls of duct tape.



A photo of the butchered locking lug would show more than our psychic vision and imaginations do for us.

[Peter Laidler]

You've all hit the nail on the head in some way or another. This was a little known modification, allowed, certainly in the L42 project, to permit the use of slightly worn bodies. If the sear was able to rise sufficient to touch the left (the small) locking lug, then the body was slightly chiseled as shown in Ed's drawing. However, if the body had already been swaged once in its life, then in order to save an otherwise perfectly serviceable body, then the bottom surface of the left hand bolt lug could be reduced in height sufficient to allow the bolt free travel fore and aft.

I don't remember the exact measurement but I believe that it could be flattened so that the flat was a maximum of 5mm or so width acress the radiussed surface. This is a feature that many people don't know about on their L42's.

The drawback was that these rifles usually had a longer first pull. Not that you'd probably notice

[Edward Horton]

Lou

The big question now is was the receiver staked to lower the sear or do you just have a ground down locking lug ala bubba or possibly DP mods????


Note: One of my No.4s was center punched in three places to lower the sear by an Armourer.

[Peter Laidler]

I bet the bloke who used the three centre punch marks got a bit of a roasting Ed! Well, he would if he'd done it in any of my workshops..... We all had a special chisel shaped tool that we would use, pretty well similar to the one you have reproduced Ed. To be honest, we would stake the sear bridge as often as it was needed because apart from the sear coming to rest against it, it wasn't a load bearing platform in any other way. The problem would usually come to light after a full complete rebuild or new bolt/sear.

The alternative was to just try to bend the sear nose down slightly. I was only joking......... PLEASE don't try it because it hard and very brittle and will snap

Interesting thread Lou. I hope that many needy grand old Enfields can be given a new lease of life

[Edward Horton]

I bet the bloke who used the three centre punch marks got a bit of a roasting Ed! Well, he would if he'd done it in any of my workshops.....

Lets keep this quite Mr. Laidler and NOT tell Amatikulu about the punch marks, it was a South African marked No.4