I am going to buy a 458 Socom upper for my ar15. I am thinking about casting heavy 458" bullets for suppressed subsonic loads. Will shooting cast bullets clog up the gas tube and lead to malfunctions? Thanks.

Ranb

I'd contact the manufacturer directly to see what their stance is on cast. If it's possible to access the gas port for cleaning, it shouldn't be an issue. Some gas opperated semi-autos have gas ports that can't be accessed, and therefore should not be shot with lead.

I'd try to find the hardest bullets I could for such an enterprise, shoot about 100, then disassemble the gas block from the barrel and see if it's clogging. If not, I should think you've got your answer.

As I get older I worry about lead vapor in gas operated semi-autos. The eject port is pretty close to the face. I have no basis for that concern other than a curious mind. When I shoot, I shoot a LOT at one time.

A friend of mine shoots cast bullets in his .223 AR-15 with fairly good results. I believe he uses linotype metal for his bullets. When I questioned him about it, he said he's been doing it for years. He also uses the, in his M1a.
Paul B.