Lee Endfield: Jungle Carbine
- Thread starter djmercer1
- Start date
Damaged or need a longer one ? No. 4 or No. 5 will fit.
why do you need to replace it? Some more info would aid us in giving the right advice.
Generally though:
Bolt heads come in various sizes and typically will run between .630" and .645" in length, measured from the face to the bearing shoulder that tightens against the front of the bolt body. You need to know what size range you need to get proper headspace and avoid things like case head separations (bad!).
Bolt heads, when new, should fully "clock" so they sit aligned to the bolt rib when tight can be inserted into the gun, but not "over-clocked" (it rotated past alignment) by more than about 7 or 8 degrees. Some allowance for more over-clocking was allowed during WW2, but if you are fitting a new head, aim for as little over-clocking as you can get. This is just done by trial and error, fitting a few bolt heads until the right one fits your bolt.
You will likely need headspaces gauges to ensure it's safe to shoot when done.
If your old bolt head was working OK before whatever happened to cause you to need a new one, start by measuring its length and look for one the same length or slightly longer. Do NOT go by the 1, 2 or 3 stamped on bolt heads. Those numbers mattered when the bolt heads were new in the supply chain, but armorers often ground the face of issued bolt heads down a few thou until the right headspace was achieved, so those numbers may not reflect actual length today. Instead measure the bolt head with calipers to be sure you get the size you need.
Good luck!
Generally though:
Bolt heads come in various sizes and typically will run between .630" and .645" in length, measured from the face to the bearing shoulder that tightens against the front of the bolt body. You need to know what size range you need to get proper headspace and avoid things like case head separations (bad!).
Bolt heads, when new, should fully "clock" so they sit aligned to the bolt rib when tight can be inserted into the gun, but not "over-clocked" (it rotated past alignment) by more than about 7 or 8 degrees. Some allowance for more over-clocking was allowed during WW2, but if you are fitting a new head, aim for as little over-clocking as you can get. This is just done by trial and error, fitting a few bolt heads until the right one fits your bolt.
You will likely need headspaces gauges to ensure it's safe to shoot when done.
If your old bolt head was working OK before whatever happened to cause you to need a new one, start by measuring its length and look for one the same length or slightly longer. Do NOT go by the 1, 2 or 3 stamped on bolt heads. Those numbers mattered when the bolt heads were new in the supply chain, but armorers often ground the face of issued bolt heads down a few thou until the right headspace was achieved, so those numbers may not reflect actual length today. Instead measure the bolt head with calipers to be sure you get the size you need.
Good luck!
I suggest a crate engine swap.
OP, your post made me smile a bit when I read it.
Because you gave little to no info about why you think you need a new or different bolt head, you recieved some answers you may not understand, or appreciate.
Many folks here are very well versed with various marks of Lee Enfield rifles, including the No 5.
Bolt heads can be difficult to find, especially the right number bolt head.
There is a very good reason No4 and No5 bolt heads have different numbers, the main one is to fit new rifles with the proper bolt head to maintain headspace within specs.
If for some reason a reciever stretches a few thou, then, if nothing else is awry, the bolt head may be changed to fix headspace issues. Same goes if the bolt has been swapped out for whatever reason.
I've seen a lot of No4 receivers with No5 (hollow bolt knob) bolts, with bolt heads that aren't correct, and No5 receivers with No4 bolts, with similar issues. They do swap out.
The reason I smiled, is today, after school was out, two of the young neighborhood boys came over with new to them Lee enfields. They are brothers, about 16-17 years old, and their Grampa gave each of them a rifle to hunt with, after completing their CORE programs. The local farmer has allowed them to take thier first Deer from his alfalfa field.
The had just come back from the range, and one of the less knowledgeable shooters up there took them under his wing, I believe this fellow is a relative of "Sunray."
He took one look at their fired cases and exclaimed, "Your rifles are dangerous, the headspace is bad, and they might KABOOM."
These youngsters are not well informed about such things and took the "experienced" shooter at his word, and headed directly to my place to see if there was any way the rifles could be fixed.
Luckily they were astute enough to bring their fired cases with them.
What I saw was "normal" expansion as would be expected in a Lee Enfield No4 or No5. The boys had one of each, which had been "sportered."
Just to be sure and to show them something physical they could understand, I did a quick "GO/NO GO" gauge test for them, and allowed them to run the test themselves, so they could understand how the gauges worked.
They were both very relieved to find their rifles were just as designed, with larger than needed chambers, so they could digest anything within spec fed into them, or maybe with a little bit of dirt.
I also explained why their chambers were a bit large, and they were happy with it.
Both of their rifles were shooting sub 3moa groups with the ammo they had, which is adequate for the ranges they will be using them. Off they went, all excited about shooting a Deer from the blind the farmer has set up.
Now, one thing I didn't go into with them, because they don't hand load, is what can be done to extend brass life and maybe make more accurate ammo.
I have two No4 rifles residing in my safe. One is a very nice little sporter made by a friend of mine, who is no longer doing such work, Chris Wilcox, and a No4 T, I put together with acquired parts. It looks OK, but it's not real.
One thing I did with both of these rifles was to swap out the bolt heads so they would not close on "maximum rim thickness cases."
It helps keep things aligned true to the axis of the bore, when in full battery.
The case taper of the 303 Brit is quite severe IMHO, and along with usually being a bit oversize, thin case rims will slightly "tilt" or ride lower in the chamber and not be concentric with the axis of the bore.
I have a lot of empty cases on hand, and carefully measure the rim thickness on them so I have .001 headspace when the bolt is closed on a full length resized case. This minimizes tilt, but not expansion, and keeps the case in closer alignment to the axis of the bore. It seems to make a bit of a difference, but not as much as I first thought.
Neither of these rifles will be moved along with the present bolt heads in them, when it's time.
I just put together a Mauser 98 chambered for the 303 Brit this spring. I ordered the reamer with a tighter chamber/neck. It has a .3082 bore. Much better bullet selection.
It's almost impossible to find an expansion ring on a full length resized case after being fired. Run out is just detectable. I've only shot fifty cases through this rifle, to fire form the brass, which will be neck sized only from now on. It's shooting into 1.5 moa with speer 180 grain flat base spire points. Hoping for good things from this rifle.
It also chambers and fires factory 303 Brit ammo, without pressure signs.
OP, way more info here than I first intended. If "someone" told you that your rifle has a headspace issue, take it to a competent smith or post some pictures of your fired cases, for knowledgeable folks to assess.
Because you gave little to no info about why you think you need a new or different bolt head, you recieved some answers you may not understand, or appreciate.
Many folks here are very well versed with various marks of Lee Enfield rifles, including the No 5.
Bolt heads can be difficult to find, especially the right number bolt head.
There is a very good reason No4 and No5 bolt heads have different numbers, the main one is to fit new rifles with the proper bolt head to maintain headspace within specs.
If for some reason a reciever stretches a few thou, then, if nothing else is awry, the bolt head may be changed to fix headspace issues. Same goes if the bolt has been swapped out for whatever reason.
I've seen a lot of No4 receivers with No5 (hollow bolt knob) bolts, with bolt heads that aren't correct, and No5 receivers with No4 bolts, with similar issues. They do swap out.
The reason I smiled, is today, after school was out, two of the young neighborhood boys came over with new to them Lee enfields. They are brothers, about 16-17 years old, and their Grampa gave each of them a rifle to hunt with, after completing their CORE programs. The local farmer has allowed them to take thier first Deer from his alfalfa field.
The had just come back from the range, and one of the less knowledgeable shooters up there took them under his wing, I believe this fellow is a relative of "Sunray."
He took one look at their fired cases and exclaimed, "Your rifles are dangerous, the headspace is bad, and they might KABOOM."
These youngsters are not well informed about such things and took the "experienced" shooter at his word, and headed directly to my place to see if there was any way the rifles could be fixed.
Luckily they were astute enough to bring their fired cases with them.
What I saw was "normal" expansion as would be expected in a Lee Enfield No4 or No5. The boys had one of each, which had been "sportered."
Just to be sure and to show them something physical they could understand, I did a quick "GO/NO GO" gauge test for them, and allowed them to run the test themselves, so they could understand how the gauges worked.
They were both very relieved to find their rifles were just as designed, with larger than needed chambers, so they could digest anything within spec fed into them, or maybe with a little bit of dirt.
I also explained why their chambers were a bit large, and they were happy with it.
Both of their rifles were shooting sub 3moa groups with the ammo they had, which is adequate for the ranges they will be using them. Off they went, all excited about shooting a Deer from the blind the farmer has set up.
Now, one thing I didn't go into with them, because they don't hand load, is what can be done to extend brass life and maybe make more accurate ammo.
I have two No4 rifles residing in my safe. One is a very nice little sporter made by a friend of mine, who is no longer doing such work, Chris Wilcox, and a No4 T, I put together with acquired parts. It looks OK, but it's not real.
One thing I did with both of these rifles was to swap out the bolt heads so they would not close on "maximum rim thickness cases."
It helps keep things aligned true to the axis of the bore, when in full battery.
The case taper of the 303 Brit is quite severe IMHO, and along with usually being a bit oversize, thin case rims will slightly "tilt" or ride lower in the chamber and not be concentric with the axis of the bore.
I have a lot of empty cases on hand, and carefully measure the rim thickness on them so I have .001 headspace when the bolt is closed on a full length resized case. This minimizes tilt, but not expansion, and keeps the case in closer alignment to the axis of the bore. It seems to make a bit of a difference, but not as much as I first thought.
Neither of these rifles will be moved along with the present bolt heads in them, when it's time.
I just put together a Mauser 98 chambered for the 303 Brit this spring. I ordered the reamer with a tighter chamber/neck. It has a .3082 bore. Much better bullet selection.
It's almost impossible to find an expansion ring on a full length resized case after being fired. Run out is just detectable. I've only shot fifty cases through this rifle, to fire form the brass, which will be neck sized only from now on. It's shooting into 1.5 moa with speer 180 grain flat base spire points. Hoping for good things from this rifle.
It also chambers and fires factory 303 Brit ammo, without pressure signs.
OP, way more info here than I first intended. If "someone" told you that your rifle has a headspace issue, take it to a competent smith or post some pictures of your fired cases, for knowledgeable folks to assess.
That's an excellent suggestion .... when the problem was a flat tire.
