How does one do a Jam to eagle grip on the high bar without injuring their shoulders. it seems like the arms are rotated to far and should dislocate.?

The "Jam" part of your question should be dealth with separately since it is complicated in and of itself. The primary objective on a jam from a handstand is to pike the legs between the arms and execute a seat circle and "dislocate" to an eagle or L-grip handstand at highest level of execution or to perform the dislocation lower and forward. To reach the handstand the primary objective is to remain upside-down with the hips leading the movement from the seat circle towards or to the handstand. Picture the hips being level or slightly higher than the head and shoulders once the legs are between the arms, then the idea is to maintain that position while swinging around the bar, even (or especially) while attampting to dislocate to handstand. The dislocate referred to is the action of rotating the shoulders so that the gymnast is able to retain a strong grasp on the bar in an L or eagle grip. The easiest way to dislocate is to slide the hands outward wide enough to allow the shoulders to "dislocate" or rotate to the proper position rather than attempting to use flexibility alone to acheive this objective. There are so many detail in learning such a complicated skill that this is only an attempt to clarify how the "dislocate" action can be suited to each athlete's flexibility to allow them to learn the skill without risking injury to their shoulders. The details of this skill are such that they are generally learned, practiced and mastered separately. Once each component of the skill has been learned then the next step is to combine them into larger and longer combinations, ultimately resulting in the performance of the skill in it's entirety. For realistic training methods, technical advice and other information seek the guidance of a qualified gymnastics instrutor or contact the USA Gymnastics Website for more information.