Well, out of 1,380,264 M14s produced, 38.94% were Harrington & Richards...They were the largest producer.
25.83% were Winchesters
23.12% were TRWs
and
12.11% were Springfields
EDIT: H&R were also the most expensive commercial variants, averaging $103.00 each. (Winchesters average $95.00 each and TRWs cost $85.54 each. Springfield production was not priced out the same as the commercial vendors, but the adjusted unit cost to the Arsenal averaged $160.95 each.)