How much do you weigh and how long have you had the saddle? I have three of the X series, and one H. They stretch a lot in the beginning but it will become less necessary over time as it stretches to fit you. All part of the process. If I were doing it all over again, I'd just buy all H series, even though I'm a little under the weight limit for the X (190 lbs). I never considered the R series because that's rubber which isn't going to break in like a leather saddle will.
Those bolts are pretty long, so you'd have to be stretching that saddle out quite a bit in order to reach the limit. How much bolt do you have still available for adjustment?