Military rifles had a sling in front of the trigger guard - normal and the Gibbs was a military-slanted accuracy rifle. I have seen pictures of a military charactature hold the rifle in 'standing' position.

The sling was choked up tight in the left fist to aid in aiming. They were attached as well to the sling swivel at the toe of the stock and when slung o the shoulder, pointed down. A long barrel might hit the ground, of course.

I've never felt that type of hold to work to my advantage. I preferred a sling further down the forend, when using a glove and hand stop.