Because I think I need it! 
I have a gimpy RIR that will probably not do well with the existing flock. (Backstory: she injured her leg somehow and I integrated the other two RIR into the main flock to give the injured bird some alone time to recup and because it was just about time for integration anyway. Note on the injury: I still do not know what happened. She still limps and seems to have trouble bearing weight, but I don't know that it's a pain issue with bearing weight as much as it is that her leg is twisted at the hock and it doesn't bear weight well in that position. She is doing better, but not great). So today I have moved her outside with the flock. An otherwise healthy bird, she will be the bottom of the pecking order and I'm not sure her injury will give her a chance to escape. I'm beginning to think that flock dynamics mean she's better off culled than left to fend for herself.
I'm 90% of the way there, but haven't fully committed because I can't seem to find the courage to get it done. These aren't pets to me. And I've had to finish off baby bunnies that my dog mutilated. The cruel irony is that I would have no problem shooting her, but I live in an incorporated area and am prohibited from discharging a firearm. Obviously I want this to be quick and as humane as possible, but I really don't think I can break the neck. I read in another thread about using a 5 gallon bucket to drown, but I'm not sure about that either. I suppose part of the problem (aside from me being an incurable softie) is that excepting the issue with being in the flock, she's otherwise healthy and would do fine by herself and someone to give her the little extras to accommodate her gimp. If she were truly ill and destined for death because of that illness, this would probably be less gut-wrenching for me. Still difficult, but I could do it knowing it was necessary.
Any words of wisdom, suggestions, or thoughts?

I have a gimpy RIR that will probably not do well with the existing flock. (Backstory: she injured her leg somehow and I integrated the other two RIR into the main flock to give the injured bird some alone time to recup and because it was just about time for integration anyway. Note on the injury: I still do not know what happened. She still limps and seems to have trouble bearing weight, but I don't know that it's a pain issue with bearing weight as much as it is that her leg is twisted at the hock and it doesn't bear weight well in that position. She is doing better, but not great). So today I have moved her outside with the flock. An otherwise healthy bird, she will be the bottom of the pecking order and I'm not sure her injury will give her a chance to escape. I'm beginning to think that flock dynamics mean she's better off culled than left to fend for herself.
I'm 90% of the way there, but haven't fully committed because I can't seem to find the courage to get it done. These aren't pets to me. And I've had to finish off baby bunnies that my dog mutilated. The cruel irony is that I would have no problem shooting her, but I live in an incorporated area and am prohibited from discharging a firearm. Obviously I want this to be quick and as humane as possible, but I really don't think I can break the neck. I read in another thread about using a 5 gallon bucket to drown, but I'm not sure about that either. I suppose part of the problem (aside from me being an incurable softie) is that excepting the issue with being in the flock, she's otherwise healthy and would do fine by herself and someone to give her the little extras to accommodate her gimp. If she were truly ill and destined for death because of that illness, this would probably be less gut-wrenching for me. Still difficult, but I could do it knowing it was necessary.
Any words of wisdom, suggestions, or thoughts?