Can you shoot 5.56 in a rossi single shot 223 rifle?

Answer 1

The one issue with 5.56 in a handi rifle is the harder primers. You will almost absolutely have to install a heavier hammer spring. I have some Malaysian 5.56 and it often won't fire in the handi. I have heard the same about the Rossi single shots.

As far as your concerns about pressures, the Handi handles all sorts of calibers on the same frame and barrel blank. Many of those push 65k or so. I don't worry about any difference in 223/556.