The 140 cubic foot acetylene tank would probably level the structure if it went
Been doing EOD/UXO stuff since 1959. i've burned a billion or two rounds of small arms ammo, mostly in open pits with scrap wood for cover, if any. Seldom does the bullet from a round project further than 20 feet from the pit.
i've burned ammo in US military cans too. 99 percent of the time the bullets just dent the can. Sometimes .50 caliber ammo will blow the can open.
Steel cased ammo in calibers 12.7mm and 14.5mm are another matter. Sometimes these rounds project small fragments of the case at a high velocity.
Most of this stuff is 5.56mm and 7.62 ammo