Hobby Boss M-4 HST/ 155MM

Are you talking about the seat behind the driver, facing forward or backward? My kit has no ammo in the passenger area. There are six seats,  two front, two facing rear and two facing forwardin the back. The 155 ammo is stored in the back compartments with a jib crane to load/ unload the ammo.  The extra ammo bin might be an ammo box for the fifty on the roof, which could be stored on the floor. I found no photos of 155 ammo being carried in the passenger compartment. Hope this helps.

Your description is spot on from my book also.The instructions are differant [ & rather non-sensical ].I tihink I'll just delete this ammo bin alltogether.It's way too large for .50 Cal ammo.Chalk it up to the differance between The real vehicle & the mechanical engineer who got involved in production of the kit ! Thanks,MECHTECH.  keith r.

I believe you're referring to the box made of parts B30 and C64.  Despite how the drawing in the instructions appears, the box actually fits into the engine compartment next to the engine.  The tabs on the bottom of B30 fit into slots on the engine bay floor - not the middle row of seats.  Part F36 is a filler pipe that sets into the box and extends through the rear chassis plate.

Thanks so much for solving the mystery,Jeff. I wish I had a prize to give you.You're pretty sharp,deducing it's location.This is actually my 1st Hobby Boss kit.I hope the next one's have clearer instructions !  keith r.