Raufoss is a place in Norway that makes all types and kinds of specialty ammunition. They make a 12.7 x 99mm (50BMG) MK211 Raufoss round that is full of RDX (like C-4) with a 30 cal tungsten penetrator in the core propelled by the explosive after some initial penetration and detonation. Many US companies also made these rounds for the US. Its initial purpose was to give to the M2 machine gun a "20mm like" energy and penetration. Its "bang" and penetration effect is highly liked by the 50 cal rifle shooters among the military (for things like killing SCUD's). Where as I have myself seen incendiary, API, APIT, and tracer, travel right through barrels and tanks of flammable liquids and gasses pressurized and un-pressurized as well as in different states of fill, without causing so much as a spark or conflagration. I truly believe that this would not be the case with this "exploding" round. For that matter, my recent experience with spotter/marker rounds although limited in their penetration by low velocity requirements. would probably still be very successful in conflagrating a barrel/cell/tank filled with flammables or powder/explosives. Raufoss rounds I saw for sale,site containing video of MK211 in action,location of video of spotter/markers in action and ammo for sale,copy of Raufoss article from FCSA,letter from Gale Mcmillan about discussion of Raufoss rounds

On the Spotter/Tracer, the original rounds loaded in the small cases might not be able to set off a target like you mention. The ones that have been loaded in the full size .50 brass should give you the desired effect that your looking for.

Try Ammoman for some S/T rounds. McMillan is wrong, if there's nothing in your state saying you can't own them, then they're legal. The amount of RDX is under what the regs are that would require a DD on them.

I can't own them or any type of API/T here in Kali but at $35 or more per bullet.... You have to ask yourself how bad you really want one.

I figured 1750 FPS from the marker/spotter shell would be the same as 1750 FPS from a full sized shell. firing the marker/spotter at speeds above that risks "in barrel" or barely post barrel disentegration of its thin jacketed warhead. I highly recommend this link to spotter marker reloaders As far as the legallity about raufoss rounds; I have always wondered about that RDX possesion and also about shipping legallity -thanks. I live in Wyoming and like 80% of our state is BLM and there is no shooting of tracer/incediary rounds from or onto BLM lands by law here. Because of this some smaller suppliers of ammo (like impactguns.com)think they cant ship here, but considering the size of our state that leaves thousands of square miles you can shoot in. its like not shipping ammo to someone because they arent allowed to shoot in city limits.

Serbu at Knob Creek had approximately 150 for sale at $35.00 each!     Thats alot for just one round.

isnt that how much the ones in the above link are? there are these ones listed by a member for $30, but its and old post www.ar15.com/forums/topic.html?b=7&f=114&t=144911&w=searchPop

Factoid:
There is a company, in TN I believe, that makes C4, C3, Semtex, etc pens.  The idea is that a small quality of explosives is desolved in a solvent so that explosive traces can be deposited on a item to test bomb sniffing dogs.  The FAA won't allow their use on FAA dog teams, but more to the point the items must be transfered as explosive material, even though the quality per pen is minimal.  I'm some what familiar with ATF explosive regs and IIRC, if the ATF director lists a substance as an explosive (the list is published annually), it is restricted, no quality is mentioned.   fireworks and bloack powder are subject to "weight" limits, but (again IIRC) material listed on the annual explosive registary is not

maybe its a route the ATF has failed to address or is keeping in their pocket until the day they come to a persons house. if one round is found they could permanently confiscate all your firearms if they dont find the "sawed-off shotgun" or "machine gun" your gun hating neighbor told them they thought you had. So it creates justification and "lawful presence" where in fact there had been none before. so in their minds a day spent at your house for a game of handcuffing, door kicking, safe torching suddenly has a purpose?