14 Republicans out of 435 members of the House of Representatives voted for some form of gun control last year. House of Reps is split almost evenly with a slight Republican majority.
15 Republican senators out of 100 senators voted for some form of gun control last year. Senate is split pretty closely. with the slimmest Democratic majority.
I think Republican support for gun control is rather trivial in the U.S.
RE: The US Gun Debate, from a Brit.