They list weight ratings for a couple of reasons I know of. One is to make sure the stand will comfortably support the weight of the hunter and the other is for legal reasons. They don't want larger hunters using their stands if it's not rated for it.
To a very high percentage, the stand will support much more than listed. However, I wouldn't test it if you are over the weight limit listed. I wouldn't hesitate to use stands at their max.
Also, I'm a big believer in safety. I always recommend for people to use a safety harness when hunting out of a stand. Safety belts are out now because just a single loop around your waist or torso can be dangerous should one actually fall. The harnesses now are better built, stronger and are designed for a fall arrest displacing the weight over a larger area.
If you're 260lbs., then with your clothes, boots, bow/gun and accessories, you'll be at least 17+lbs. more. You're good to go.
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