Military hair

I am a woman who has mid-back length thick hair. I need some suggestions on putting my hair up military style - a tight bun. Usually I put my brush my bang hair (long length) into a barrette at the crown, make pony tail at the back and braid/coil my hair into a bun at the back. I wear a peak cap and the extra bulk is giving me a headache. I got a larger hat from stores (larger sizes 7 1/2 are rare) If I go without the barrette at the crown, the hair tends to fall out over my ears. Is there a way to section hair and wrap it into a bun. I`ve tried bun wrapper chignon maker things but I can`t get the hang of it and they don`t really work if there is a pony tail in the hair first.
We are allowed to wear our hair in a tight bun or french braid tucked up under the hat. Barrettes, pins, combs and hairnets are allowed provided they are the same colour as the hair.

I would appreciate any advice. Merci en advance.

I use a fabric covered wire that rolls my hair up in a bun that does not come loose no matter what. Got it from a site called Cam-Laur twister.com My hair is not as long as yours so I don`t know if it will work as bra strap length is the longest I have had my hair while in the military and my arms can only reach so far. hope this helps some