Hi ATS,
Eric and Ron are bang on. I find red maple often has more vivid curl and figure than hard maple (which can be sugar or closely related, black maple). However, sometimes it is not dense enough to carve well or at least easily. The gun below was made from red maple. I love the figure but carving it was a nightmare because it had very soft areas. In fact, when I stained it with ferric nitrate dissolved in water, some of the crisp edges of the carving just crumbled away and I had to recut those areas.
The next gun was stocked in very hard sugar maple. It was a delight to carve and I had no issues with edges crumbling or detail being lost. However, although sold as highly figured maple, you can see the curl is not nearly as vivid as the previous rifle.
My best advice is if you want a plain rifle with no carving but beautiful wood, consider red maple. If you want to carve a lot of detail, consider sugar or black maple. Either way, always pick the blank that weighs the most.
dave