"Slabside" 1st production lower
First type production "M16" lower, mfg 1959-1963 used on the 601 & 602, known as "slabside" due to it being completely flat on the right side in the mag well area, this lower used a different type pivot pin than later versions that had a small ball bearing at the end of the pin that "snapped" into the counterbore on the left side of the uppers pivot pin lug. This type pin had a problem in the field as it came out fairly easily & could be lost in the field. Also note the hole at rear where the receiver extension (buffer tube) screwed in, early type tubes were screwed in then this hole was drilled thru the lower & the tube threads & a 3/32 roll pin inserted to lock the tube to the lower. The lower shown is a NoDakSpud semi 601 replica & is an EXCELLENT product as is all their M16 series replica semi lowers.
Other Sizes: Original