Mickey: Two friends here both are what I'd call "cougar nuts". Both have killed more than I ever will, and both use very different calibers for kitties. My buddy John below uses his Mini-14 and 55gr NBT's, and reports all one-shot kills.
John with one of his cats:
And at the other end of the spectrum, here's my other friend with a recent cat taken with his trusty Marlin 980 in 22 Mag. He's taken well over 200 cats in his lifetime using the same rifle, but he does use his hounds and trees them before lighting off the Marlin.
I guess the point here is that "yes", the 204R is completely capable of taking cougar with the proper bullet, but shot placement is as always the most important aspect of the equation. I'll also agree that if you do intend to hunt cats with the 204R, the Berger 35gr would be my first choice also.
Good luck, and if you bag a cat, we'll want pics!
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