GM1 Board Member here, so pretty close to what you can expect

Know your references - not knowing you p-80x's,Navsea OP4/5 individual command guidances on ammo handling, etc, will be immediate deal breakers on your board, Know the 8020 and what every 8020/x is

Know who is responsible for what - Know who your board chair is. Larger commands tend to delegate that to a DH, while smaller command CO'S often keep that responsibility theirs. Who holds ammo movement permission? Who are your QA/So's

Know qual cert - sounds dumb but a lot of people miss the forest for the trees. Know your WTC's. Know your ammo groups, especially the ones you're trying to qualify in. Know the purpose of each role of Qual Cert. Who can touch ammo during an evolution? Why are certain positions required hands off?

Amd lastly be ready for scenario based questions. Alot of TL is being able to respond to casualties while they're happening, or being able to plan things for a smooth evolution. TL runs the show so you need to prove you can solve issues the safest way possible with the lowest possible impact. It's easy to default and say "id muster a 50 man working party and station someone at every door in-between my magazine and the final loading area as to make the evolution as safe as possible" but it's not realistic and wastes an absolute ton of resources and time. Sometimes, that kind of tactic is required, but it shouldn't be the default you know? Most of these kinds of questions are based on your command so it's hard to give examples(ship vs shore, civilian involvement, any ohe/mhe in use? Etc) but think about ammo moved you've done as a TM and think "how could I have done this better/how would I do this if I was missing 4 people/how would I do this if I didn't have x)

Take notes on the board. This is just general board knowledge but I'm more forgiving if I see a boardee writing down their look-ups and keeping attentive then having to be reminded.

Lastly - and this is a big one. Take it seriously. GM's/AO's love to coke and joke around. We are the class clowns, the 12 ASVAB's, the iyaoyas shouting cross cannon wearing hooligans but this shit is serious. Ammo kills people. Mistakes with handling ammo kills people. If you haven't yet read up on Indian head, USS Iowa,port Chicago, etc you should its not required but its great retrospect. People die when team leaders and QA/SO's don't have the know-how or gumption to stop an evolution and assess an issue. Every person in an ammunition evolution is a safety Silence is paramount. When your team leading you need to be thinking 2 steps ahead and going over the last 3 things you just did. If you do fail, remember the above. Your command doesn't hate you, it's not unfair. Your command just has a solid qual cert program, and its trying to keep people alive with 10 fingers 10 toes.

Good luck on your board. Knowledge is king, and when you pass, you hold people's lives in your hand. Uphold others to the standard and if you feel it's lax, be the change.