This is how most people shoot bullsye. Keep in mind I mean bullseye the specific shooting sport not bullseye as in a very accurate shot.
The idea is to stand in the most neutral and naturally balanced position possible. The off hand is in his pocket to keep it still so it moving doesn't move the rest of his body.
In places where real guns are legal most bullseye is shot with 1911s, a semi auto chambered in 45acp. The slide would pop you in the face, very painful, if you stood how most olympic competitors stand. Olymipic is 22 caliber and often air powered, WAY less recoil.