Why was the Springfield 1903 30-06 made to cock on opening ? ...

[dogtag]

Interesting stuff, but as yet nothing about the advantage of COO compared with COC.

And here's another question: Why was a third locking lug needed when as far
as I know the up front lugs had never failed ?

Was the 03 that much more accurate ? Well maybe. remember the old adage:
Lee Enfield - best battle rifle.
Mauser - best hunting rifle.
1903 - the best target rifle

[Johnny P]

The K98k and the 1903 Springfield both cock on opening. The firing pin doesn't move as the bolt handle is turned down, but the bolt sleeve moves forward as the bolt handle is turned down, turning the locking lugs into the receiver.
The resistance on opening the bolt handle on either rifle is the cocking motion.

[Roadkingtrax]

Cock on close is simply the more antiquated, and cheaper of the two to produce. COO is stronger, safer, and the mechanical action of the controlled feed and rotating bolt aids in the feeding of rounds. The third lug was never necessary, but an added safety feature of the 1903/Mauser design. COO uses a heavier spring, which favors mechanical advantages, COC uses a lighter spring.

England loves its tradition, so why change what was working.

[lyman]

This is a misconception. After the Boer war the Brits completely overhauled their rifle doctrine. There are some excellent episodes on "British Muzzleloaders" on you tube relating to this. The Brits didn't do much bullseye shooting, most qualification was on various silouette targets at ranges out to 500 yards. There was some emphasis on timed aimed fire but true volley fire was not British doctrine after 1900, definitely after 1909. British soldiers were trained to engage individual targets and put them down, just like we were; though the methods for getting there varied.

Interestingly the last "great power" to actually use volley fire was Russia, whose M1891 Mosin-Nagant rifle cocked on opening.

This part on the series about WW I British rifle training concentrates on the most misunderstood phase of all, the "Mad Minute." This is straight from the training manuals and course of fire used by the Brit soldier of WWI.

https://www.youtube.com/watch?v=SCLT-5pDrKk

British Muzzleloading is a great youtube channel
Paper Cartridges is another

[blackhawknj]

I wonder if anyone actually paid attention at the time. I have a Winchester M-69, it cocks on closing, it was redesign to cock on opening and redesign acted the M-69A, an economy move no doubt.