Strength of Jungle Carbine action
- Thread starter hawkin user
- Start date
It will handle any load a regular #4 will. The military used the same ammunition in them. Lyman data will work.
daddylonglegs
CGN Regular
- Location
- Big River, Saskatchewan
I had a custom 45-70 built on a Jungle Carbine action. I worked up some loads that were 5 grains of powder more than Ken Water's absolute maximum load for use only in Ruger No. 1 actions. 5 shots in 3/4" at 100 yds, 540 gr. cast bullet doing 1725 fps. No signs of over pressure. The gun and action worked flawlessly although recoil was some-what stout! The Lee Enfield No 4 & 5 actions are a lot stronger than given credit for.
Cartridges of the World states that the normal operating pressure for the 303 Brit is 46,000-48,000psi.
Then goes on to mention many No4 receivers were re barreled to accept the 7.62x51 Nato cartridge, which has a normal operating pressure of 62,000psi.
Without being contradictory, if you don't understand how the action accepts pressure, and you're not sure about the condition of the receiver or barrel, then take the rifle to someone with experience. No, I'm not talking about your beer buddy circle. Take it to a smith for evaluation.
Likely, if there is nothing visibly wrong with it and headspace is OK, he will just tell you that any factory loads or loads from the Lyman manual you have are fine.
Many of these old rifles were converted to all sorts of cartridges that generate more pressure than the SAAMI specs or milspecs.
The 45-70 load mentioned above, doesn't come close to the pressures the action is capable of tolerating as a steady diet. I would guess that the pressures in the loads used by daddylonglegs was right around 40,000psi at best.
Then goes on to mention many No4 receivers were re barreled to accept the 7.62x51 Nato cartridge, which has a normal operating pressure of 62,000psi.
Without being contradictory, if you don't understand how the action accepts pressure, and you're not sure about the condition of the receiver or barrel, then take the rifle to someone with experience. No, I'm not talking about your beer buddy circle. Take it to a smith for evaluation.
Likely, if there is nothing visibly wrong with it and headspace is OK, he will just tell you that any factory loads or loads from the Lyman manual you have are fine.
Many of these old rifles were converted to all sorts of cartridges that generate more pressure than the SAAMI specs or milspecs.
The 45-70 load mentioned above, doesn't come close to the pressures the action is capable of tolerating as a steady diet. I would guess that the pressures in the loads used by daddylonglegs was right around 40,000psi at best.
- Location
- Western Manitoba
For another purpose I was looking up some pressure standards earlier today - so SAAMI sets limit of 50,000 CUP and 60,000 PSI for 30-06 - one is using Copper Crusher technique and other is using Transducer - I do not think the measuring or testing protocols are the same - the results are NOT expressed in the same units. And I notice that bullet weight, velocity, or recoil does not appear to have anything to do with what "pressure" a particular round will create, at least as per SAAMI or CIP standards.
Not arguing by any means...postulating one might say. The metal removed to make a Jungle carbine lighter... is none of that near the receiver?
- Location
- WMU247 near Edmonton
some material was removed from the rear of the receiver but the area that seats the locking lugs are not effected.
the No5 is plenty strong and full power 303 rounds are perfectly safe.
now is the No5 as strong as the No4, that might be debatable, but I'm not firing full power 300WM rounds (oiled) out of a No4 for fun either....
I grew up dragging a JC around. But I'm not a kool aid drinker on them, dad bought it as a youth, said it never shot worth a darn...and he never knew about 'Wandering Zero'... he said it just wasn't accurate.
Que someone to eminently sound off about my father's lack of ability because they can shoot the eye out of a bird flying with theirs... which no-one really believes.
Entertaining enough... but not the main drive of the question. Seems I read the metal removed might have contributed to the Wandering Zero... I know, no such thing though, right?
But that would remove a bit of the feel good safety feeling when shooting it with a hotter caliber...again, no such thing though.
My first one never shot well either after it got hot. All over. But the new one seems okay. If it can handle mk7 .303 I'm not to worried about anything close to that in terms of pressure. They saw service with no reported failures.
Look how much oiled up 300wm it took bloke on the range to mess a no4 bolt up. And it failed at a pre existing defect. Not as weak as the sewing circle always claims
Look how much oiled up 300wm it took bloke on the range to mess a no4 bolt up. And it failed at a pre existing defect. Not as weak as the sewing circle always claims
Lee Enfield
CGN Ultra frequent flyer
- Location
- Republic of Alberta
Sterling and Charnwood Ordnance converted No5 rifles to 7.62 Nato.
So they obviously passed the 19T proof testing.
Remember that .303 Bri No5 barrels have large lightening cuts in the knox form - that and the shortened forend probably contribes to the "wandering zero" reputation.
I don't know if anyone has invested any time in looking at the bedding on various No5 rifles, but I have a one that is in New condition - all numbers match, Zero bolt head, no marks on the feed ramp, 100 percent perfect rifling, no erosion, no lost finish, no marks anywhere, and with storage grease in various places around the action, and whoever fitted it up should be thrown off a bridge, it's shockingly bad. I'll need to shim it if I ever decide to deflower it. I think that that may be where wandering zero was born. also real Mk VII is not anything like SAAMI 303 - just saying
enefgee, I have invested quite a bit of time and money into getting sporterized No5 rifles to ''consistantly'' shoot accurately, hot or cold.
I agree with you completely, the main culprit for the No5 accuracy issues have been bedding 99% of the time.
Various bore diameters are another, but most No5 barrels are remarkably consistent and very close to or slightly under mean spec.
I've also found they shoot better WITHOUT THE FLASH SUPPRESSOR.
The best No5 sporters I've made up and shot were all glass bedded around the receiver ways, king screw and had a 1/32 in gap between the socket and fore end. I also added a block to dampen harmonics appx seven inches up the fore end barrel channel to apply pressure. This block needs to be ''adjusted" for every build and I usually add a bit to much wood, then rasp it out until the rifle shoots the load I use well.
One of the problems with Lee Enfield sporter bedding, is the fore end is held by ONE King Screw. It doesn't matter that there is a spacer to stop it from being compressed, it acts as a fulcrum point, which works against the ways every time the rifle is handled. The pressure pad on the underside of the barrel, where it's noticeably thicker, works to stop the rocking motion and protects the ways, which I glass bed.
Just for full disclosure, this doesn't magicly turn the No5 into a ''tack driver'' but it usually settles things down to the point where they will hold under two inches at 100 yds, with off the shelf ammo in a reliably consistent manner.
I don't believe the lightening cuts at the Knox or the bit on the receiver, or the shortened barrel have much to do with the wandering zero.
I agree with you completely, the main culprit for the No5 accuracy issues have been bedding 99% of the time.
Various bore diameters are another, but most No5 barrels are remarkably consistent and very close to or slightly under mean spec.
I've also found they shoot better WITHOUT THE FLASH SUPPRESSOR.
The best No5 sporters I've made up and shot were all glass bedded around the receiver ways, king screw and had a 1/32 in gap between the socket and fore end. I also added a block to dampen harmonics appx seven inches up the fore end barrel channel to apply pressure. This block needs to be ''adjusted" for every build and I usually add a bit to much wood, then rasp it out until the rifle shoots the load I use well.
One of the problems with Lee Enfield sporter bedding, is the fore end is held by ONE King Screw. It doesn't matter that there is a spacer to stop it from being compressed, it acts as a fulcrum point, which works against the ways every time the rifle is handled. The pressure pad on the underside of the barrel, where it's noticeably thicker, works to stop the rocking motion and protects the ways, which I glass bed.
Just for full disclosure, this doesn't magicly turn the No5 into a ''tack driver'' but it usually settles things down to the point where they will hold under two inches at 100 yds, with off the shelf ammo in a reliably consistent manner.
I don't believe the lightening cuts at the Knox or the bit on the receiver, or the shortened barrel have much to do with the wandering zero.
I've always been curious if the "wandering zero" was part soldier excuse making, and part (by today's standards) slack manufacturing tolerances. "Precision" machining is a constantly evolving process. What would have been perfectly acceptable and considered high end tolerances, in the 50's, wouldn't pass muster at any but the lowest end manufacturers today.
The engineered strength of the older actions was phenomenal, but it had to be, because the engineers knew they had to over-design to account for the variables in manufacturing. From variations in steel quality, to machine tooling that would invariably be used long past when it should have been replaced, to tolerances within the tooling itself, from one lathe to the next.
All of that gets better in slow steps as manufacturing evolves. Some of the guns we look at as "cheap and cheerful" now, would have been absolute marvels in the 40's and 50's.
The engineered strength of the older actions was phenomenal, but it had to be, because the engineers knew they had to over-design to account for the variables in manufacturing. From variations in steel quality, to machine tooling that would invariably be used long past when it should have been replaced, to tolerances within the tooling itself, from one lathe to the next.
All of that gets better in slow steps as manufacturing evolves. Some of the guns we look at as "cheap and cheerful" now, would have been absolute marvels in the 40's and 50's.
First thing to understand about the engineering behind military rifles. They get ridden hard and put away wet when being used under stressful conditions.
The earliest Lee Enfields were multi tools, being designed for ease of carry, reasonable accuracy for the time, cost efficiency during production, soldier proof.
When a rifle is in the field whether the situation is volatile or not, things go wrong. Ammo gets dropped in the mud/dirt, mud/dirt get into the bore/action, water gets into the bore, temps drop below -40c and the list goes on.
These rifles have to stand up to outrageous issues and still come through it ready for a fight in a safe, reliable manner.
Of course they're ''over engineered'' they have to be.
Just because they're over engineered, doesn't mean the design is perfect, even though it's more than adequate for the intended use.
Lee Enfields usually have two piece stocks, which is unusual for bolt action designs, with French 1886 and later Mas36 as well as the G33/40 types which were also exceptions to the norm.
Both the French designs as well as that of the G33/40 utilized much better bedding systems than the Lee Enfield types, IMHO.
This was done for a number of reasons, some of which are cost per unit, ease of retaining good wood and reduction of warpage/strength at the weakest point, the wrist.
The Lee Enfield's weakness is in its bedding. When it's done properly, they are very good all around.
The sad thing is that all sorts of things cause the bedding to go awry, from warpage to shrinkage and even expansion.
All of this is beyond the control of the designers/troopie.
Then there are troopies that try to ''fix'' these issues in the field, usually just making things worse and putting the rifle out of use until a unit armorer can put it back into acceptable working state.
No5 rifles are a Lee Enfield variant and in some cases, things such as the shortened fore end and addition of the flash suppressor, which is more for the shooter's benefit than to hide it from the enemy.
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Blastattack
CGN Ultra frequent flyer
- Location
- Winnipeg MB
Bloke on the Range built and proofed a No 4 with .300 Win Mag (which is proof loads and oiled rounds) and it passed proofing without issue. I think it took another 10 round of proof loads to cause damage, and that damage was already present from manufacturing. That means anything that will fit in the gun will be safe to shoot under normal circumstances.
And y’all talk about pressure like it’s some meaningful thing. It’s honestly irrelevant. Bolt thrust is what actually matters, it’s derived using pressure, but it’s ultimately what matters when it comes to an action failing.
And y’all talk about pressure like it’s some meaningful thing. It’s honestly irrelevant. Bolt thrust is what actually matters, it’s derived using pressure, but it’s ultimately what matters when it comes to an action failing.
