Thread: "Weak" Rear Locker Lee Enfield No 4 action vs .300 Win Mag

Most interesting test. "Weak" rear locker LE No 4 Mk 1/2 action with "H" barrel, shooting .300 Winchester Magnum

Vividly demonstrates increased safety margin to be had from using A CLEAN CARTRIDGE IN A CLEAN CHAMBER.

Watched that the other night, seeing what actually caused the failure was interesting.

Very cool video, I always enjoy watching his stuff.

Water on the outside of a case can have the same effect as oil. Well worth remembering...

30 odd years ago did a 303 I.C.B.M which was a sort of Ackley, could run the 180 grns to 2800fps no worries

bloody intriguing video-good old .303 eh hardass till the end .metal fatigue -whod have guessed that .my old no4mk1 stays in the safe -a 180 gn sn slug down the big hole suffices to cure any problems modern engineering cant.

I wonder what the pressure was since the bullet was under bore diameter?

Perhaps getting a chamber cut to 8x57R and squeezing a oversize bullet down the bore would give a better idea of action strength?

I know a M98 will handle a case full of N-110,I wonder if a Lee Enfield would do the same?

Originally Posted by norsk

I wonder what the pressure was since the bullet was under bore diameter?

Perhaps getting a chamber cut to 8x57R and squeezing a oversize bullet down the bore would give a better idea of action strength?

I know a M98 will handle a case full of N-110,I wonder if a Lee Enfield would do the same?

The bore was correct as it was a No 4 action, re-barreled/chambered to .300 Win Mag.

But what pressure would you expect from a .303 case full of N-110 and pushing an 180 grain jacketed projectile?

As for ultimate strength, not sure. It did well here. The advantage of the m98 mauser with forward locking lugs is more strength for weight, as it does not need a strong entire receiver like the rear locking Lee action. A .303 Mauser would be lighter therefore than a .303 Lee, but the Mauser would have longer bolt travel, more degrees bolt handle lift and it could fail more catastrophically if the lugs gave way. The Mauser would not have a bolt body to flex and bend between the cartridge face and locking lugs, which allows the Lee to fail more safely for the shooter, with a bent bolt occurring before lug failure occurs.

What I'm saying is, the Mauser and Lee actions alike can be manufactured to handle any cartridge. The No 4 was made to handle .303 but with what looks like a considerable safety margin based on this video.

I'd worry about loading .303 cases to .308 pressures, as the .308 has a cylindrical chamber-gripping case... but the .303 has a cone-bodied easy-extraction case that will give more pressure back against the bolt face. Add oil or water to the outside of a conical case and the bolt face will really feel it. It is not over engineered but engineered to cope with that.

Originally Posted by Cordite

The bore was correct as it was a No 4 action, re-barreled/chambered to .300 Win Mag.

If it was rechambered the pressure would be quite a bit lower as the bullet would be riding the grooves.Especially if the barrel was worn

But what pressure would you expect from a .303 case full of N-110 and pushing an 180 grain jacketed projectile?

Huge

As for ultimate strength, not sure. It did well here. The advantage of the m98 mauser with forward locking lugs is more strength for weight, as it does not need a strong entire receiver like the rear locking Lee action. A .303 Mauser would be lighter therefore than a .303 Lee, but the Mauser would have longer bolt travel, more degrees bolt handle lift and it could fail more catastrophically if the lugs gave way. The Mauser would not have ua bolt body to flex and bend between the cartridge face and locking lugs, which allows the Lee to fail more safely for the shooter, with a bent bolt occurring before lug failure occurs.

Have you ever Cut a Mauser action up? There is alot of steel behind the lugs,a third lug on the bolt body and the bolt handle.

What I'm saying is, the Mauser and Lee actions alike can be manufactured to handle any cartridge. The No 4 was made to handle .303 but with what looks like a considerable safety margin based on this video.

I'd worry about loading .303 cases to .308 pressures, as the .308 has a cylindrical chamber-gripping case... but the .303 has a cone-bodied easy-extraction case that will give more pressure back against the bolt face. Add oil or water to the outside of a conical case and the bolt face will really feel it. It is not over engineered but engineered to cope with that.

I see where you are coming from but there is not much research on bolt thrust.

Originally Posted by Cordite

The bore was correct as it was a No 4 action, re-barreled/chambered to .300 Win Mag.

But what pressure would you expect from a .303 case full of N-110 and pushing an 180 grain jacketed projectile?

As for ultimate strength, not sure. It did well here. The advantage of the m98 mauser with forward locking lugs is more strength for weight, as it does not need a strong entire receiver like the rear locking Lee action. A .303 Mauser would be lighter therefore than a .303 Lee, but the Mauser would have longer bolt travel, more degrees bolt handle lift and it could fail more catastrophically if the lugs gave way. The Mauser would not have a bolt body to flex and bend between the cartridge face and locking lugs, which allows the Lee to fail more safely for the shooter, with a bent bolt occurring before lug failure occurs.

What I'm saying is, the Mauser and Lee actions alike can be manufactured to handle any cartridge. The No 4 was made to handle .303 but with what looks like a considerable safety margin based on this video.

I'd worry about loading .303 cases to .308 pressures, as the .308 has a cylindrical chamber-gripping case... but the .303 has a cone-bodied easy-extraction case that will give more pressure back against the bolt face. Add oil or water to the outside of a conical case and the bolt face will really feel it. It is not over engineered but engineered to cope with that.

I was just reading somewhere about that and that there is something with the rimmed cartridges and extractor having a different behavior to a rimless due to the extractor being outside the diameter of the case. I wills ee if I can find it again as it may make more sense to someone on here. Either way I also just watched a video on a rear locking 40 calibre elephant cartridge.....

Edit: It may well have been in the video itself....getting older sucks...

@norsk
Agree both types have extra safety features. No military or civilian market for dangerous-to-user firearms.

I understood from the video the rifle was a 7.62 NATO No.4 rechambered for .300 win mag. For the reason you give the test would not make much sense otherwise.

For those who think 1 grain over max is going to be nuclear
https://youtu.be/gfiXFyIbOZw?t=954

And there is a Part 2 . And then for some fun
https://youtu.be/ZN8l9gEeDK4

Originally Posted by Tankd

For those who think 1 grain over max is going to be nuclear
https://youtu.be/gfiXFyIbOZw?t=954

And there is a Part 2 . And then for some fun
https://youtu.be/ZN8l9gEeDK4

I have to say that many years ago I did something similar to a polish carbine version. It had very little rifling left (which probably helped). Most of the torture test involved first filling the barrel with obstructions and then hammering the barrel into the ground. We went through the whole packet of military and then started on some hot .308 loads (yes they will chamber and fire but don't recommend trying). Eventually a locking lug failed. Impressively strong auction.

I’m not convinced that’s a manufacture fault. It looks like it’s slowly torn over time.