By Default SGKv2 attaches weapons to the Right Hand bone of the character, this works for the included weapons but you may need to attach new weapons to your characters weapon bone instead. You can follow this guide to attach your weapon to the weapon bone and have the weapon bone effected by the right hand IK values to allow for using the IK system to adjust the weapons position.
Keep in mind that the character animations you use for your weapon need to have been animated to use the weapon bone, if their not then when these animations play the weapon will not be in the correct location as it will be attached to the weapon bone and that bone wont move when the animations play.
Start by going to the ABP_BaseHoldableAnimLayer, create a Boolean variable called UseWeaponBone and tick on Instance Editable in its settings then copy the video below.
Next you will need to add a new socket to your weapon bone in the characters skeleton, to add the socket right click the weapon bone in your characters skeleton and select Add Socket and name it.
Depending on your character animations you may also have to adjust that sockets location and rotation, ideally your animation will have the weapon bone in the correct position and wont require the socket to be adjusted.
Next go to your weapons holdable blueprint and in the Class Defaults search for socket, here you can set the Hold Socket like the image below.
You can then open your weapons animation layer blueprint and in the Class Defaults tick on the UseWeaponBone option. This option will be avalible in all the animation layer blueprints so you can enabled and disable this individually for each weapon.
After doing this your weapon will now attach to your characters weapon bone, and if you have the right hand IKs enabled in the weapons holdable anim layers this will set the weapon bones position. You will likely need to readjust your weapons right hand ik position there is a guide for that linked below.
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