Full disclosure. I hate westerns. They've been done to death. It's not a very important part of history, but it's all that American's really have, so they fixate on it.
Having said that, I am so glad that I read this. It literally took my breath away. As soon as I realized where the ending was going I became anxious about Carrie's fate and exhilarated at the audacity and cold-blooded nature of his decision.My heart raced. You also strung it out long enough to raise hopes that he would change his mind. Well done, you really made me feel heightened emotions at the end, and that's the whole purpose. I also felt for the two leads, and they certainly had an arc.
The three would-be kidnappers felt a little out of central casting though. Can you think of anything we've not seen before to differentiate them? It also suffered from killing off the main antagonist early.
It was very evocative and I felt transported, so great voice and consistent sense of controlled tone.
It wasn't perfect though (yet), either technically (see below) or as a story. I felt it lagged a little in the shoot outs. The shoot out was 16 pages, about 40% of the story. It's well done, and is engaging, and is obviously a big part of why the ending works, but anything that can be done to make it more unique would be welcome. It would probably play better than it reads.
You only describe Carrie in terms of her physical attributes. This is frowned upon. What are her traits? What's she like as a person? Also, you have to call her Carrie in the dialogue from the start, even if we don't know her name yet.
The shared laugh on page 10 feels unearned and as if it came out of no where. As does the raising of his hand, and argument on page 12 -13. It might need a little more build up. The conflict didn't feel genuine.
Digging out a bullet to save someone is such a trope / cliche. It only exists in movies. Surgeons often leave bullets in place so the patient doesn't bleed out. The bullet could be all that's stopping further bleeding. It would actually be more unexpected / unique to leave it there, or stitch him up, after all, it has "stopped bleeding." Or maybe they don't know any better?
Carrie's shirt buttons popping on page 29 feels a little soft core porn. Also, Billy's not a virgin (bottom of page 29) but he's not seen bare breasts before? That seems unlikely. Also, page 31, wouldn't carry have evidence if she'd been violated? Wouldn't she know?
Overall, it's good and I look forward to reading more from you.