Had my collie for the last 8 and a bit years, she is my 3rd collie, the first two have both been great working with sheep but were both completely gun shy. As a working dog in an area of several pheasant shoots they could be a nightmare, setting off for home while leaving me to move the sheep when a barrage of shots rang out in the distance.
I dropped lucky with this one, doesn't turn a hair at the rifle going off and is as excited as any Wire Hair Pointer when she sees me moving the rifle from my van to the ATV.
I've had her from 6 months old from a breeder in Worcestershire, she's three quarter welsh , one quarter border. It soon became apparent that she had a fantastic nose, started on active mole hills, then to watching the moles as they moved between the hills then pointing mice in tussocks of grass, she lets me know when any rats are in occupation by standing staring at the drains and walking her in the evening on the estate she would point to the bracken and wait as badger walked out onto her nose! Never chased them, just likes finding em!
She trained up easily on the sheep work and I decided to try her finding deer. Having shot one from a seat on an open ride I dragged it 50m off to the side into an area of brambles. Fetched her from the landy and walked her down the ride just encouraging her to sniff about. As soon as we got to the shot point her head was down sniffing and licking the blood then looked about and took off into the scrub and ran straight to the deer. I did this just a few times and on the third or forth time, rather than walking with me to where it was shot she stopped looking off the main ride we were walking in on. She had scented the deer already which was 100m away and when I sent her off she did a straight line to it rather than the curves route I was taking her in on.
In short, if you can get one like mine, they are so intelligent and obedient that once they know what you are wanting they are dead keen to do it for you, whether that is finding a shot deer that's run off the track or walking with you and air scenting and pointing to warn you of where they are, collies can be fantastic. She wont do the job that I know some deer dogs do, as in pulling down something that isn't quite dead, but she will give them a good licking to clean up any blood!
Good luck with it