Ever shot a rattler?

I've lived in Arizona for 8 years but only last night had my first encounter
with a rattler. It was good and riled up from being hassled by my cat. I
heard the rattles and it was really loud. When I went outside to investigate
what I thought might be a broken hose bib, the 4+ foot serpent charged
towards me. I retreated into my workshop and the cat soon followed. The
snake sat coiled by the door and stopped rattling after about two minutes.
Just about had a heart attack.

I have an H&R 9 shot .22 revolver loaded with shot shells ready in case the
snake gives me a chance to dispatch it. My question is - at what range will
the gun be effective and how many shots should do the trick? Any other
advice is welcome.

Thanks

Dan in New River
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