That's a great photo you have there, Buckskin Billy. I have been wanting to visit Bent's Fort... One of these days, I reckon.
There is a lot more on the Beckwourth Rifle, with detailed descriptions of the various aspects of the rifle's design, some really excellent photographs and drawings, and the story of how the rifle was authenticated here: James P. Beckwourth Rifle
I think Beckwourth was known to "improve upon" the truth, but this was not an uncommon practice. If you read Bill Hamilton's My Sixty Years on the Plains
or **** Wootton's "Uncle ****" Wootton
, these two make it sound as if they were critical participants in every major event. I understand a lot of the details of Jim Beckwourth's autobiography actually hold up pretty well in comparison to historical fact-checking.
Crooked River Bob