reloading and the 7.62 No.4

[whiterider]

Ok that little stamp put on the left side of the action usually under the charger guide was put on by the Lithgow small arms factory after 'crack testing' the action before installing a 7.62 barrel and proofing.

As far as I am aware (and I stand corrected if a 'real' expert comes along) I recall hearing that it was a 'dye penetrant' examination of locking lug recess and shoulder...but I'm unsure if it encompased the whole action as such.

A few years ago much 'hoo hah' was put about by our National Rifle Association here in Australia about 'certain ex-military actions being not strong enough for commercial loads' of the 7.62 cartridge... Among those listed were the No.4 Lee Enfield and the M 98 Mauser.... Apparently the NRA put out this advice after information from a gunsmsith of some renown...

The advice went to say that 'only military ammunition or its equivalent and CERTAINLY NOT COMMERCIAL LOADED 308 ammo should be used in 'conversions'...

Now it should be fairly obvious to most reloaders that it takes more than just BULLET WEIGHT to constitute pressure...barrel internal dimensions, chamber cut and of course POWDER TYPE AND WEIGHT OF CHARGE all need to be taken into account. So limiting No. 4 conversions to a bullet weight of 144 grains WITHOUT ANY OTHER INFORMATION seems a bit ridiculous.

Now the strength of the No.4 action has been and will probably continue to be the subject of much argument. AS FAR AS I AM AWARE the only No.4 rifles known and documented to have suffered failure in service have been those 'cadet' rifles in the UK...and they suffered a barrel split not a failure of the action...

So make up your own minds about the safety of the No.4 action...I've put my eyes and head where my mouth is and have used them without a problem for many many years. I dont use hot loads in them and (by measurement of the fired case in a case guage) I keep a close watch on headspace, stretching of the action and any battering of the locking lugs or recesses.

Perhaps the learned engineer Mr. Horton could advise us further on the Lithgow crack testing process. I say this with sincerity and not sarcasm.