The kneeling position is one of the toughest positions for many people. It’s uncomfortable and can be pretty tricky to get consistent. Hopefully, this tip can help you get into your kneeling position more comfortably, consistently, but more importantly, with more stability.
Here is Brody, an Adventure Ranger in Arizona. Brody is left handed. He is practicing the kneeling position as he works on his Advanced BB Gun merit. Now, notice where his forward foot is in this picture. It is not in line with his support arm/hand. It is off to the right, pointing at his target. This is causing unneeded torque on his grip and forcing him to compensate for it with his arm. This leads to more wobble and he flexes and relaxes his arm to try to keep the gun centered on target. This is exhausting and can cause unneeded movement and a loss of accuracy.
To correct this I asked Brody to move his foot towards the left, a bit at a time, until it was directly under his support hand. He can extend the leg and move his foot away or nearer to his body to adjust for elevation, but it needs to remain in line with the support hand and arm. This provides a solid foundation directly under the gun. It eliminates the torque and mitigates the struggle to keep the gun centered on target.
There is much more that goes into shooting in the kneeling position, but I hope this tip helps you as much as it has helped Brody.