I thought it was an excellent movie. Earlier I read the book. The author is an expert in Texas history but doesn't know a lot about firearms.
Hanks had some shotgun ammo with birdshot and the little girl ran and got the coins. They dumped out the birdshot and loaded the dimes. In the book, IIRC, the shotgun was 20 gauge and they were trying to kill the bad guys at 200 yards with the dimes. Dimes probably won't fit in 20 gauge. That was the only unrealistic part, except for Hanks briefly extracting spent cases from an 1860 Army.
