Thread: fix for worn out bolt for no4 lee enfield?
Retrieved: 06/08/2014
Is there any way to salvage a worn out Lee Enfield bolt that allows the bolt head to turn to far past the side rib when out of the rifle? Perhaps a washer or something?
bearhunter
10-08-2013
That isn't all that unusual and as long as your headspace is OK, nothing to worry about.
These rifles and their parts were produced on a mass production basis. They had plus or minus tolerances.
The reason your bolt head turns past the sweet spot is because the bolt body itself is slightly short. Likely only a few thousandths of an inch. Even unissued rifles or lightly used rifles can have this condition.
You might be able to change this with another bolt head. MIGHT.
RRCo.
10-08-2013
Up to 20 degrees past the main recoil lug on the bolt was permissible they say, but less is better. The more bolt head over-turn there is, the less primary extraction you have.
Swapping bolt heads was how the military addressed this.
How far over does yours turn?
scott585
10-09-2013
Its at about 45 degrees, or almost completely past the bolt rib.
kennymo
10-09-2013
Marstar has both used and unissued bolts in stock, as well as two sizes of bolt head.
bigedp51
10-09-2013
Below is a composite photo of one bolt body that has been fitted with four different bolt heads, due to bolt thrust the bolt bodies mating surface with the bolt head has shortened. The mating surface of the bolt body to the bolt head has been peened just like a hammer hitting a metal stake. This bolt needs to be replaced and there is no fix, the bolt is now scrap junk metal. The manual calls for the bolt to be replace, and if a new bolt and a No.3 bolt head .638 in length closes on the .074 headspace gauge the rifle will be turned in for FTR overhaul. (in most cases the receiver will need to be replaced due to lug recess setback)
scott585 is absolutely correct above, once the bolt head rotates past 20 degrees the threads will start to take the full force of the bolt thrust and more damage will occur. Any time over rotation happens with several bolt heads being fitted the bolt "must" be replaced.
PICTURE 404
The inspection criteria above can be found in the manual below.
PICTURE 404
And the most accurate method for checking for stretching and thinning in the base web area is a RCBS case mastering gauge. Bent wires or paperclips are only for white collar office workers, blue collar working class people have hit their fingers so many times with hammers they have no feeling left in them to feel any thinning in the case. (I could drag a bent paper clip across Niagara Falls and not feel it)
scott585
10-09-2013
This one looks like the second pic down.
It headspaces nicely with a new bolt and a No.1 head, but the old bolt matched the rifle.
bigedp51
10-09-2013
Replace the bolt head and find one that will line up just shy of the locking lug and work the two mating surfaces together.
PICTURE 404
You want a tight fitting replacement bolt head that barely lines up and must be worked into alignment. If the bolt head lines up easily after firing a few hundred rounds the bolt head may over rotate after the two parts are seated together.
PICTURE 404
bearhunter
10-09-2013
its at about 45 degrees, or almost completely past the bolt rib
You should have mentioned that it was so far out in your OP. Eking out bits of information leads to getting wrong answers.
They're right, get a new bolt if the travel is over 20 degrees.
bigedp51
10-09-2013
People you can download your own copy of the Canadian No.4 Enfield rifle at the links below and educate yourself and be ahead of the game. The 1991 manual has bedding drawings and bedding adjustments, the 2002 manual does not.
1991 No.4 (All Marks) .303 Rifle Manuals (Complete Set)
2002 No.4 (All Marks) .303 Rifle Manuals (Complete Set)
There is a wealth of Enfield information at this site and its your own fault if you do not download it and "READ" it.
If you don't download these free manuals you should be shot with a dull bullet, be drawn and quartered, burned at the stake, have your library card revoked and your internet connection cut off. I was also going to say your scrotum should be set on fire and the flames be put out with a sledge hammer, but that might be going to extremes.
RRCo.
10-10-2013
I think I should correct my earlier comment insofar as primary extraction is concerned. The camming action of the bolt is probably sufficient for primary extraction with even an extreme amount of overturn like that shown. As Ed points out, the issue is whether the thrust of firing is transferred to the threads or the matching faces on the front of the bolt body and the rear of the bolt head.
20 degrees is pretty extreme as a tolerance and I suspect the threads are taking some of the thrust in that case. I believe the L42A1 had a 12 degree overturn limit. From some experiments with a feeler gauge and a good bolt just now, there seems to be about 4 thou of clearance, that is 2 thou on either side effectively, between the male thread of the bolt head and the female thread in the bolt body. So when pulled up tight, the male threads of the bolt head are drawn forward, off the forward faces of the female thread and onto the rearward faces, ensuring that the thrust of firing goes only through the bolt body, not the threads.
The funny thing is, the bearing surfaces of the threads taken as a whole are probably at least as large an area as the front and rear faces of the bolt and bolt head! So why does it matter?
Two reasons I suspect: the collar on the firing pin should rest against the rear face of the bolt head shank when not cocked, and if the bolt head slammed into the collar every time the rifle was fired, fatigue failure would follow inevitably. (Obviously the collar does slam into the bolt head as the firing pin reaches the end of its forward travel, but an almost simultaneous backwards thrust would add a lot to the stresses probably)
Second, the bolt head has a fair amount of lateral play in the bolt body and the "squareness" of the face of the bolt head to the chamber is critical for accuracy, so perhaps the bolt head needs to bear against the forward face of the bolt body when the bolt is closed to maintain that "squareness".
bigedp51
10-10-2013
The bolt head doesn't rotate the bolt does, therefore the bolt head has nothing to do with primary extraction other than the fact that the extractor is fastened to the bolt head. The Canadian manual is written differently than the British instruction for armourers to keep the Enfield rifle in service in the absence of repair and replacement parts.
As an example there is a reference to bending the trigger guard for trigger pull adjustments. Capt Peter Laidler sent a PM to me once asking why this was done, the answer is simple, there are no more replacement fore stocks. The British would replace the fore stock when the wood was compressed over .010 below the receiver and trigger guard because the lobes on the trigger could not be adjusted for proper trigger pull.
Another example is the British used bolt head timing when fitting a bolt head and this is nothing more than "when" the rear of the bolt head is to contact the collar of the firing pin as the bolt head makes its last turn before stopping. The British used the 3:00 position for contact or 90 degrees before lining up with the locking lug. The Canadian manual tells you to replace the bolt head if it does not push the firing pin and cocking piece 1/16 to 1/64 to the rear. Meaning the Canadian manual uses a wider tolerance and a "air gap" between the rear of the bolt and cocking piece for adjustment. What this means is bolt head timing is from 5:00 to 2;00 and makes more use of worn parts.
Bottom line the Canadian manual is the perfect manual for anyone owning a No.4 Enfield rifle and wants to keep the rifle servicable. Anything else would be a myth and borderline hammer and chisel maintenance.
RRCo.
10-10-2013
I have both, and while it's been a while since I looked at them, I felt the British EMER's were much more comprehensive in gauging, dimensions and tolerances. The graphics in the CF manual and indeed the whole presentation is more "dumbed down", which probably reflected a lack of continuity in the training and skill sets to maintain the No.4. Not to mention the equipment to do so. It would be interesting to know what the CF manuals looked like before the 1984 version, and the subsequent revisions of it.