The M1 Garand rifle uses an enbloc clip of eight (8) rounds.  The clip holds the ammunition and is inserted with the ammunition into the rifle.  During operation, the M1 feeds the ammunition from the clip until the last shot.  On the last shot, both the fired case and the empty clip are automatically ejected with a distinctive TWANG!  M1 rifles fire either caliber .30 (.30-06 Springfield) cartridge or, when rebarreled, can fire the 7.62x51 NATO round.  In both cases, the standard eight round clip is used. 

 

There was a 10-round version of the M1 built by the Japanese at the end of WW2.  This rifle was chambered for the 7.7x58 Japanese rimless cartridge of the bolt action Type 99 Arisaka rifle.  It was a reverse-engineered copy of the M1 that used the Japanese five round stripper clips to load a 10-shot internal magazine.  Only five prototypes are known to have existed before the war's end in 1945.

 

During WW2, American soldiers complained that the eight shots weren't really enough -- running out of ammo and having to fumble about for a new clip in the midst of a shootout is not good in combat -- and that the TWANG! of the expended clip was a tipoff to the enemy that the shooter was out of ammo.  Springfield Armory, Springfield, Massachusetts, developed the T20-series of rifles based on modified M1s that could use the standard 20-round BAR magazines.  Had WW2 continued into 1946, the T20 was scheduled for production for use in the conquest of the Japanese home islands.

 

However, WW2 inded on 2 September 1945 and T20 production remained in development.  The advent of NATO and a common cartridge (7.62x51 NATO) led to the T44-series of rifles that competed head-to-head with the Belgian FN FAL.  Both rifles were select-fire and used a 20-round magazine.  The final shoot-off testing between the American-built T44 and T48 prototypes was completed in 1956.  The competition was a draw.  After lobbying by the Army's Ordnance Corps and Springfield Armory, the Secretary of the Army type classified the T44E4 rifle as U.S. Rifle, Cal. 7.62 NATO, M14 in 1957.