First, if you have a custody order that has never been changed and it indicates the mother has custody, the mother may take the child back at any time.
Second, even if custody was changed to indoicate your spouse will have the children in his care, the law gives preference to placing the child in a parent's care unless you can demonstrate that there is some endangerment factor. Growing distant or being yelled aat may fall short of endangerment.
Third, if your spouse is off to boot camp, does it also mean he will be active duty after the boot camp is over? If so, how will he be able to care for the child?
In the end, your best chance is to file a Motion and seek to prove endangerment. It will not be an easy task given the facts presented.