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

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...