Back in the 70's when fox pelts were worth a bit we used to use a tape of a young chicken - recorded in the bathroom - where we "wriggled" it around a bit to get the distressed sounds.
On the first try shot 3 foxes in about 2 minutes, They literally ran straight at the sound.
We must have called a couple of hundred foxes all in all.
I have often thought of making another one but no more chooks
In those days the calibre of choice was the Rem 17, That rifle is now the 223 AI
Regards
Bravo 27
