HW's 21yo rye is 53%, though it's not straight as it's been aged in used oak.
Just a technical point on the regs. It's actually not that it can't be called "straight" because of the used cooperage, it's that it can be called "rye whiskey". Rye whiskey, like bourbon, must be aged in new charred oak barrels. If you look at the lable on the 21, it's not "rye whiskey", it's "whiskey distilled from rye mash."