Problem with No4 MkI Bolt

[Brian Dick]

I'm stumped without having it in hand. The bolt assembly is out of spec. and needs to be sorted. That much I can see. I recently had an SMLE come here for barreling and I found the body had been blown up and the rear of the breech ring was physically blown upwards and backwards, (the first I'd ever seen), so that's a possibility as Bruce has said although the physical damage isn't evident on your No.4. A wild *** guess is that your body is just plain worn out beyond repair with the bolt flopping around in the runway but I could be wrong.

[Surpmil]

That photo showing the rear of the chamber looks odd. You should be able to see a clearly-defined "collar" in the body, just behind the actual barrel face. The barrel should not be touching this "collar" (known as the "inner ring" because No4s breech up on the front of the Body, as opposed to all its predecessors, which, like a Mauser, breeched up against that inner ring....

I agree, it does look a bit odd, but there is no sign of another extractor slot, so unless it has been set back an entire turn and the slot deepened...? Someone who wanted to recut the chamber with a smaller than milspec reamer?

Maybe take off the rear handguard and lets see the Nock's Form?

[Brian Dick]

I doubt it's been set back as the forend wouldn't fit properly unless it was shortened and the cap refitted. I had a genius send me Long Branch many years ago that was done that way and it was completely knackered. He had unbreeched it through the magazine well using a bar of tool steel and twisted the body in the process. The result was I sold him a new rifle after unsuccessfully trying to repair it. Did you know that the bolt head will religiously pop out of the cut in the rail when the body is twisted? I didn't at the time but I sure learned! It was a wartime Canadian owned/issued rifle too which was really sad as they aren't that common.

[Surpmil]

I had a 1957 Mk.2 receiver someone had done that to as well. I suppose the bolt was gone and he didn't think it was worth anything...

[jonh172]

My first thought was this rifle had a bar inserted to twist the receiver off.
I’m dealing with one myself.

OP

Look inside the corners from underneath in the mag well, do you see signs of force applied?
If a bar was used to take the action off the damage would be inside the mag well openings.
If the top left side of the action was moved left (Bent outwards when bar was forced against it) it could be causing your bolt to sit too far left and disconnecting it from the rail when fired.

In your pictures I can’t see any damage to the upper left side rail but maybe it was dressed down??? I dunno, pretty big spit ball...

[dewey1424]

My intent is to turn this rifle over to the "pro" but that's on hold for now. It turns out I'm one of those old guys who is supposed to be careful and stay home for a while. In the mean time, here is a picture of the Knox form and a mark on the right side of the barrel. The blurry feature closest to the receiver looks like four closely spaced punches. Is that a hardness verification? The mark on the right of the barrel looks like 'F 52." Is that a barrel date, matching up with the 1952 FTR? There is also a mark on the right side near the muzzle that looks like "NP 18 Ton," a number 2, and something else illegible.



Be safe.
Keep Calm and Wash Your Hands.

---------- Post added at 02:30 PM ---------- Previous post was at 02:21 PM ----------

Not sure what I'm looking for here.

[Alan de Enfield]

The mark on the right of the barrel looks like 'F 52." Is that a barrel date, matching up with the 1952 FTR? There is also a mark on the right side near the muzzle that looks like "NP 18 Ton," a number 2, and something else illegible.

F52 = Barrel year
NP 18 ton = BNP 18 tons per sq inch (Civilian Proof test when it was sold into the UK Civilian gun market)
2xxx = 2.222" = cartridge length

Should be 303" calibre marking in there as well

[Surpmil]

I am having a problem with a No 4 Mk I....

The problem is that when fired, the bolt head jumps out of the track. I have to hand raise it to the vertical release orientation to get the bolt open.

It seems to open and close smoothly with no round in the chamber.

The only other observation I have is that the bolt head does not tighten flush with the bolt body when the bolt and bolt head are aligned, so there is a little play between the bold head and bolt body. (Does that make sense?)....

Could this problem be caused by my re-assembly or do I have a bigger problem with this rifle?

Thanks.

Now that we've seen the photos, personally I can't see any way in which the bolt head could escape the guide rail when the bolt is closed and the rifle is fired.

Nor can I see any way for the bolt head to be "raised to vertical" with the bolt closed, even if there was no rail at all, as the extractor and spring cannot rotate to vertical without being withdrawn from the extractor slot in the barrel & receiver.

2+2 does not equal 5.

[browningautorifle]

I would save all the conjecture and send it off to Brian Dick at BDL Ltd and let him sweat it out. Here's a link, PM him... https://www.milsurps.com/member.php?u=2818

[Jsne]

Any pictures of fired cases?

Jsne