If you mean that metal plug that seats as a bullet and gets pushed back when chambering, no. At least not that I know of. But, they are quite simple to make if you know someone who has a small metal lathe; I've made a half dozen or so.
Thanks Boomtube.
I thought about that but for $6.95 and it would give me an excuse too order something else
so I would'nt have to pay shipping on such a small item.