Tim
The Erquiaga Ams EM62 Modification of the M1 Garand is not at all like a BM 59 modification.
The EM62 uses
A new 7.62mm barrel 18 1/4 " long that is heavier than a Garand, M14 or BM59 barrel
The gas port is .087 inches in dia. and 12 inches forward from the rear of the barrel.
A new drop down type gas cylinder is used. It is pinned to the barred by two roll pins.
The top of the gas cylinder is dove tailed for a standard M1 front sight. The cylinder tube
is 5 1/4" long and extends into the stock channel.
The op rod is straight and is 13" long overall.
The op rod spring guide is patterned after an M14 op rod spring guide including using
the end as the front magazine catch.
The rear receiver legs are unmodified. The front legs are thinned but not V cut. The
front of the receiver is opened to to accept the M14 mag. The bottom front of the
receiver is also opened up to accept a magazine guide. This guide is held in by the
follower pin. It is also milled to allow the recoil spring guide to pass thru.
A rear spacer block with the magazine catch and bolt hold open is utilized. This block
has a rib on each side. The ribs allow the spacer block to slide into the enbloc clip
grooves on the rear receiver legs. The ledges on the rear legs acts as stops and the
trigger houses keeps it in place.
The only modifications to the trigger housing is being milled out for the magazine and a
small clearance cut for the magazine catch.
The stock is modified with the magazine cut out, stock ferrule lip is removed and the
ferrule is opened up to allow the gas cylinder tube to pass thru.
The bolt appears to be unmodified.
All in all it appears to be not a complex modification and the magazine is forward unlike
the BM59.