Adding another question mark, I came across this.
Subject: Re: Garand Navy 308 Question
Date: 10 Mar 1999 10:22:13 -0500
I'm really surprized at all the incorrect information posted regarding these US
Navy M1 Garands in 7.62mm NATO. If anybody chooses to talk with anyone
directly involved in the USN's NATO Garand program in the middle 1960s, here's
what they will learn.
In the early 1960s, the USN Small Arms Marksmanship Unit in San Diego (located
at what used to be Camp Elliot south of Miramar NAS) wanted to do two things.
One was to upgrade all their rifles used for training recruits at USNTC San
Diego to use the 7.62mm NATO round. The other was to upgrade all their match
grade service rifles to the same cartridge. Virtually all of this was
spearheaded by Charles Frazier; a retired Navy chief petty officer who went to
work as a civil service employee of the US Navy. Charlie ran the Match
Conditioning Unit where work on both rifles and pistols was as good as it got.
Someone suggested a chamber insert. Several were made and the project came up
with what seemed to work well. But after a long period of testing and use,
and several of these inserts comming out with the empty case, this idea was
quickly abandoned. There were fewer problems by just using a 7.62mm NATO round
in an unmodified .30-06 service chamber.
The US Navy contacted Springfield Armory in Mass. to make a batch of barrels on
the same machines used to make them for the 30 caliber Garands. The only
differences were the bore was rifled 1:12 (30 caliber barrels were 1:10) and
chamber them for the 7.62mm NATO round. All these barrels were broach cut
rifled. They were all stamped "7.62 NATO) on their right side just in front of
the tenon shoulder and this is visible when the op rod is pulled back. They
were also date stamped in 1964 or 1965; the year they were made. And they were
all chrome-moly material; none were made in stainless steel.
At the USN Small Arms Match Conditioning Unit at the same place as the Training
Unit, all these M1 7.62mm barrels were measured with a Sheffield air gage for
groove diameter uniformity. Those with the smallest groove diameters with most
uniformity were set aside for use in the match grade M1s. About 40% of about
3000 or so barrels met this criteria. All the rest were set aside for use in
standard training rifles. The last two numbers of the groove diameter was
scribed on the barrel. If the groove diameter was .3078 inch, "78" was put on
the barrel. Groove diameters ranged from .3077- to .3082-inch. Those at or
under .3079-inch were considered match-grade. Most interesting was how uniform
in groove diameters these broach-cut barrels were.
As the M1s were first being converted, it was found that in test firing, the
gas supplied to the op rod to function the rifle was not quite enough with the
standard 30 caliber barrels's gas port diameter. These holes had to be opened
up a few thousandths of an inch. It was a standard operating procedure that
when a new 7.62mm M1 barrel was pulled from the box to go in a rifle, the gas
port was drilled out. The second thing that was done was to knurl the barrel
where the lower band went so it would be a tighter fit.
I've watched the shop crew rebarrel many 30 caliber M1s to service and match
grade 7.62mm NATO Garands. It doesn't take very long to drill and knurl the
barrel, strip the barrel group of an M1, put the barreled action in the
barreling machine, replace the barrel, then put everything back together. The
big difference is what they did to the match grade ones in fitting all the
parts and using the select-grade barrels for them. Especially in how the gas
cylinder and op rod were fitted as well as epoxy bedding the receiver with the
barrel set in the right thickness of spacer on the stock's front end to get the
right amount of pull-down pressure when the lower band was on the ferrule.
They didn't stamp the receiver with any new markings. Nor did they mark
anything else special with either the service or match grade M1s they
converted. But there was one exception. Anybody who's actually used on of the
match grade ones has noted the color mark on the gas cylinder lock ring; they
were color coded as to how they clocked up tight on the barrel against the gas
Each grade, service or match, was given a Mark and Mod designation; I don't
remember what they were.
Some interesting things about these M1s. Four of them were used in the late
1960s by a USN team to beat the best bolt gun team in the USA at a long range
match. Match-grade M1 service rifles from the USN SAMCU are the only service
rifles ever used by anybody making the US Palma Team; nobody's ever made the US
Palma Team using an M14 (for readers thinking the M14 or M1A is an excellent
long-range rifle...). In machine rest tests, the USN M1s shot about 30% more
accurate than those from the US Army or US Marine Corps marksmanship units.
An interesting thing about these match-grade 7.62 Garands. The most accurate
of all of them were built by a former USN Pistol Team member. He shot pistol
for many years and was pretty good at it. He was also on Ford Island in Pearl
Harbor on the morning of Dec. 7, 1941 as a young 3rd class petty officer. Two
years later, he was promoted to Chief Petty Officer. When he retired from the
USN in the late '50s, he went to work as a mechanic for the government and soon
ended up at the USN SAMCU. He worked very close with Charlie Frazier to learn
what really was needed to make the M1 Garand shoot virtually as good as the
best bolt action match rifles of the day. His name is Don "Mac" McCoy. Still
alive and well in San Diego.
Sometime in the 1970s, there had been enough problems with people trying to
insert a clip of 30 caliber ammo into a 308 M1 and having the rounds not
chamber. The USN designed a white, plastic like insert that went in the
receiver to prevent a clip of 30 caliber ammo being put in.
Of course, it was also not cool for someone going to a match at Camp Elliot in
this era with a 30 claiber M1 and not knowing this, then drawing 7.62mm ammo to
shoot. After a dozen or so empty cases laying nearby were observed to not have
any shoulder on them, the user oft times didn't get concerned at all. In fact,
a couple of folks shot all 50 or 60 record shots this way and didn't even know
By about 1973, all the match-grade 7.62mm NATO Garand barrels had been used up.
There were a few service-grade barrels left but they were used in rebarreling
shot-out NATO Garands of USN Rifle Team members until they were gone by the