IK Constraints lagging one frame when animating

Hi,

Would anyone be able to explain to me why, in the attached blender file, the IK constraints on the arms are lagging behind the guns between frame 0 and frame 4000.

Thanks

pre-bake player model.blend (3.08 MB)

You posted your question on the wrong thread.

It may be your computer is not so fast. I bet it renders fine. I can not detect a lag here.

Sounds like a dependency cycle to me.
(BTW this section is for posting finished animation rather than asking for help)