I'm really getting into smallbore silhouette and I've now bought amarlin 22 for cowboy smallbore. I think I want to try centerfire cowboy. I like the new stainless marlins and I think that the 30-30 round is cheap to reload.
Are the stainless Marlins in 30-30 legal for cowboy centerfire if I use roundnose or flat nose bullets?

If you mean the 336XLR, then yes it sure is. In fact, it looks like it was designed specifically for the game. It has the long barrel, 5-shot magazine, and good heft to it. Throw on a good receiver peep sight and a good aperture front sight with a good insert and you're ready for slamming down those 200-meter rams.

Glen, I would also like to add that Marlin is going to chamber the 336XLR for the new 308 Marlin. I know this is a brand new cartridge, but it should be pretty good from a ballistic standpoint. Al

Yep. It's already on the website. With the volume that competitive shooters shoot, though, I'm not sure it would be worth it since the reloading components will be more expensive and you'll still have to use flat or round-nosed bullets and the 30-30 doesn't have any problem knocking the rams down as it is.

You know, Centerfire Cowboy is very much on my list of things to do in the next couple of years. Having not thought about it much, I was hoping to use something from my Savage 99 collection, but it looks like it has to be a flat-nose, rimmed cartridge from a tube-feeder. Linky

While disappointing, it certainly seems to keep the equipment on a fairly level field.