that's why i use sliding leather finger loops/straps.
The leather stops any rubbing that you get with a pure cord loop. And sliding means it's always snug on the finger and won't rotate and rub.
I don't just do this stuff at random you know
For the big trebuchet sling I used a large wide leather 'loop' that fitted over two fingers.
I did sling some with gloves on at hodd hill. But that's because when it wasn't snowing, it was sleeting and bloody cold !
Another advantage of a sliding loop - it will fit over a gloved finger as easily as an ungloved finger