US Military's Mixing 7.62 & .308 in Same Rifle
I just read the article. On a scale of 1 to 10, it's a 12. Maybe a 13 (bad luck to those who think it's trash, outstanding to those who know better). I'll add some spice to enhance it's flavor.
After shooting my first M1 during USN boot camp small arms week back in 1956, I became quite interested in small arms marksmanship. When learning about the 4-year-old cartridge, I wrote Mike Walker at Remington (he championed the team that developed the cartridge) and asked about interchangeability between 7.62 and .308 rounds. He wrote back saying they're the same in rifles but not in most folk's minds because of the military versions having slightly different dimensions in chamber and cartridge than commercial versions. He aslo said that in spite of Remington's success of modifying a .300 Savage case and designing what's probably the most accurate 30 caliber round ever, Winchester trumped 'em in the card game of commercial cartridges 'cause they got the first big contract for ammo.
When I started shooting highpower competition in 1964, I used a Navy converted M1 shooting the 7.62 round. (Note: It wasn't until the 1970's that the Army and Marine armorers could build an M14 to equal the accuracy of those Garands.) I'd heard civilians talk about all those "incompatibilities" between the two versions of this round. When some of them saw me shooting Remington .308 match ammo in my 7.62 Garand, they sometimes asked why I was doing such a dangerous thing. My answer was the same as the USMC and US Army using M14's and the USAF using 7.62 M1's; "It shoots more accurate than M118 match ammo!" Most civilians understood they're interchangeable but about 10% of them told us we were _____ (you fill in this blank with your favorite word for dumb, ignorant and/or stupid people).
A friend of mine who used to be on the USAF team (also the first person to shoot the .308 Win. at the US Nationals) had developed a very accurate load for long range use in 7.62 Garands; M118 new primed case with 44 grains of IMR4320 and a Sierra 190 HPMK seated out to almost touch the lands. It's peak pressure was close to that of a blue pill (proof round). The USN Small Arms Match Conditioning Unit in San Diego made this load which won a lot of long range matches. The Unit (and perhaps the USMC and US Army teams) also made "Mexican Match" ammo by pulling bullets from special lots of 7.62 M80 ball (LC12638 and LC12484) and seating a Sierra 168 in 'em. Both lots used 42 grains of a non-canistered powder, IMR4475, that Lake City used for the 8-round clipped ammo for converted USAF and USN Garands as well as their blue pill proof loads. This also was about the most accurate ammo through 600 yards I've shot in 7.62 Garands. All the services' members shooting this stuff in competition were told not to give any of it to the civilians paying the taxes that supported the military competitors. Peak pressures were close to, it not equal to proof loads.
With the above in mind, I called Lake City Arsenal in the early '70's and talked to an engineer involved with load development and accuracy testing. He said their 7.62 NATO proof loads were essentially the same as the Navy's Mexican Match. The difference was they used a 172-gr. match bullet instead of the 147-gr. ball version in the same case with the same 42-gr. of IMR4475. He said he'd heard about the USN and USAF using "blue pill proof loads" in their Garands and oft times shuddered just thinking about it. But we never had any problems.
At the National Service Rifle Matches held at Camp Perry, all the military teams told the civilians to "never" use their 7.62 NATO match ammo in civilian rifles. There was a "safety" problem. Of course, all the military competitors knew they were completely interchangeable and did so by using commercial .308 match ammo in their M1's and M14's and the knowledgeable civilians used M118 match and M80 ball ammo in their bolt guns with total confidence and safety. It was in the late '60's and early '70's that the phrase "political correctness" became popular and a lot of us military competitors feel this 7.62 vs. .308 ammo controversy was the prime cause.
At the 1971 National Matches as a USN Rifle Team member, I was the first person in the USA to complete the standard course of fire with an M16. In talking with military folks from other services then and a few weeks before at the Interservice Matches in Quantico, VA, we discussed the issues of 7.62 vs. .308 and knew it would occur again in another form; 5.56 vs. .223. A few civilians asked us about that at the '71 Nationals and said the differences were the same as those for 7.62 vs. .308. Most interesting, as I observed later, this 22 caliber issue never grew to the magnitude of the 30 caliber one.
When I was on the 1988 US Palma Team and later US International Teams shooting the .308, I learned that the USA ain't the only country where some folks believe the two rounds are separate in every way and safe use requirements. I doubt the issue will go away peacefully.
Kudos for the article. Knowledgeable people will applaud it. Others (and we know who they are) will condemn it.