Well, if there is no firing pin/striker on the hammer, if the hammer face is basically flat but with a small step at the top, it has a transfer bar.
Not on a Rossi. I have owned two 511 .22s (one got stolen), a M88, a M971, and a M68. My 92 carbine is a Rossi, but it don't count. ALL the centerfires had hammer mounted firing pins and a hammer block. My M68 (still have) was bought in 1981 new, hammer block. My 511 Sportsman .22s, however, have a flat faced hammer, but no transfer bar. They incorporate a hammer block with the frame mounted firing pin. I just went and checked mine to make sure before I posted this.
Anyway, every one of 'em were/are safe with a full cylinder. They are quite decent hanguns, too. I've had a couple of firing pins on a 971 break on me before it got fixed right, but that's the worst problem I ever had. That gun had 8 or 10K rounds through it when I traded it. Really liked shooting it, but I made a good trade with it on a .45 Colt stainless blackhawk I wanted more. Rossis are higher quality guns than most will tell you that never owned one. They tend to have decent to very respectable accuracy (my current 511 is amazing). They vary in quality of fit and finish. The late 80s, early 90s seems to be when they were the worst, tooling marks and such, and occasionally you'd pick one up who's timing was less than impressive, but my M68 bought in 81 is spot on, well put together and finished, and very accurate. And, quality in the newer Rossis seems to be back to early 80s levels from what I've seen of 'em. I'd like to get a M462, nice gun, pocket sized .357 6 shooter. But, I have a Ruger SP101 AND a 3" Taurus M66 medium frame, so I don't really need it.