I've got a Samick Explorer that I've been using to experiment with carbons for the past couple of years. Mine weigh out around 440 grains and I'm pulling 50 pounds on it. Shouldn't have been too light, but the bottom limb cracked on the bow yesterday. I can't say for sure if the carbons had anything to do with it, but it's the first bought-new recurve I've ever broken in 48 years of shooting and it's the only recurve I've ever regularly shot carbon with.