Force aim animation

Hi everyone, I'm trying (unsuccessfully so far) to force the aiming animation. I noticed that when you equip a weapon with the gun pose set, the animation plays for about 2 seconds (the player extends their forearm). I'd like to keep that animation active until the weapon is unequipped. Another way to achieve a similar result is by holding down the right mouse button—but without the camera focusing and without disabling the run. Is that possible?