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Thag lurn!
A while back I mentioned that 7.62x51mm NATO is a lengthened .300 Savage and got haughtily informed that it was really a shortened .30-06.
Well, it turns out both positions are correct.
When the "30-06 but shorter" thing got started they actually looked to using .300 Savage unmodified to replace it. But .300 Savage didn't quite have the velocity they wanted and lacked the case capacity to do anything about it.
Never mind what this new "magnum" version of the round would do in extant Savage 99's.
So they lengthened the round just a smidge and got the velocity they were looking for.
Done! Say hello to 7.62 NATO!
Not quite.
As with so many ammunition related things, tooling and fixtures come up.
Then some finer elements of case design start showing up in testing.
Fix that angle, address that diameter, change that radius.
Until the round is almost literally a shortened 30-06...
But the path didn't start with shortening the older round.
Nah, it is really a shortened 7.5x54 French MAS! :-D
ReplyDeleteSurprisingly, from what I've seen, and despite the French not exactly being famous for engineering... the MAS rifles (both the bolt actions and semi autos) that chambered that round were actually surprisingly competently designed. So any issues the French Army had... must have been something else. Despite my German ancestry I will resist the temptation to say what that might be.
One thing that annoys me is the existence of ".308 Winchester" alongside ".308 NATO." I've never been sure if .308 Winchester is safe to shoot from guns designed for .308 NATO, and can't see why we need two such similar calibers of ammunition in the first place.
ReplyDeleteI wish I'd covered the question of interchange between the "two" rounds on August 7, 2014. That would have been a good thing to write a post about.
DeleteHey!
https://mcthag.blogspot.com/2014/08/disservice.html
For the record, it was commercially unfeasible to name a round with the "universal" metric system in the 50's and 60's. This is why we have .308 Winchester and .223 Remington instead of 7.62x51 and 5.56x45. Metric denoted furrin... and generally undesirable.
DeleteMuch of the difference between SAAMI and NATO specifications comes from the ammo companies setting the SAAMI spec early to be first to market and military firearms having different needs with regards to chamber dimensions because full auto and much higher sustained rates of fire than a hunting rifle.