rolf wroteI don't think that stuff is legal/allowed in your checked in luggage at all. Is it?
You must be having a stopover somewhere in Europe. In Europe ammunition are not allowed in luggage but I don't know if it applies to transit.
If I travel with one airline with a transit in between, the checked-in baggage will not be re-scanned during the transit period.
Also, the TSA's stand on ammunition transportation:
TSA requires that ammunition be placed in an appropriate container:
“securely packed in fiber, wood, or metal boxes, or other packaging
specifically designed to carry small amounts of ammunition.” Loose
ammunition isn’t allowed, not even in an ammo can. FAA regulations
stipulate that the primers be protected/covered.
Most airlines prefer ammunition to be in its original packaging from the
manufacturer. Commercial plastic ammunition cases designed for reloaded
ammo, such as MTM Case-Gard ammo boxes, are also fine. It’s a good idea
to tape all ammo boxes shut to prevent any accidental spillage.
Prior to booking, familiarize yourself with airline limitations on the number
of firearms that can be transported in a single case, rules regarding excess
baggage exemptions, and limitations on the amount of ammunition that may
be transported. Limitations may be based on weight (commonly 11 pounds
gross weight per passenger, especially on international flights) or quantity,
depending on the airline.