"BBL" is the abbrevation for "barrel".
Or were you looking for origin? It is abbreviation from barrel as used in shipping
e.g.: barrel of beer.
Back in the olden times when a farmer would toss an old barrel on the back of the buckboard, and go buy some "coal oil" or kerosene, barrels came in all sizes.
Somehow, 40 gallons was determined to be a barrel of water, and when a guy purchased a barrel of kerosene, he expected the same. It was dispensed with a meter. Many people were suspicious of being shorted, so a directive went out from an oil company to charge for a 40 gallon barrel, but to pump until the meter read 42 gallons, so the purchaser was assured he had at least 40 gallons.
And from this, the standard "barrel" became standardized at 42 gallons.
It is this liquid barrel (=42 gallons) that is abbrieviated "bbl". That abbrieviation has been used by some for a rifle's barrel.
Do not confuse the barrel (as a unit of measure) with the 55 gallon drum... which, BTW, is made to hold 50 gallons with some airspace.
On June 18, 2002, the following conversation took place. No names were changed.
[23:28:20] <jetlag> Why does bbl = barrel?
[23:28:29] <Kar98> be back later
[23:28:42] <jetlag> Yeah, I meant in other circumstances.
[23:28:47] <Kar98> why bbl = barrel, I dunno
[23:29:04] <Kar98> big barrel?
[23:32:02] <EricTheHun> bbl is an abbreviation from the oil fields
[23:32:11] <brouhaha> lol, ETH
[23:32:35] <brouhaha> I don't understand how bbl=barrel, but it does
[23:32:37] <EricTheHun> it simply means blue barrels
[23:32:43] <brouhaha> blue? really?
[23:32:49] <JAFO> BBL Barrel Volume measurement. One Barrel=159 litres
[23:33:00] <EricTheHun> they marked good barrels with a blue X, meaning it had no holes in it
[23:33:05] <JAFO> don't know the origin either
[23:33:10] <imho> did not know that
[23:33:12] <JAFO> blue, cool
[23:33:24] <EricTheHun> A bbl of oil is 42 gallons, BTW, know why?
[23:33:33] <imho> Why, Hun?
[23:34:00] <brouhaha> that's ok...mcf=thousand cubic feet. mmcf=million cubic feet
[23:34:03] <EricTheHun> They were using 50 gal barrels, but none of the barrels had lids
[23:34:11] <imho> Yes?
[23:34:20] <EricTheHun> By the time the barrel was delivered, 8 gallons had sloshed out
[23:34:34] <imho> Haha
[23:34:45] <EricTheHun> So they decided to put lids on them, but kept them at 42 gallons for obvious reasons - money
[23:34:57] <imho> Oh, that's the truth, eh?
[23:35:05] <imho> Well. . .
[23:35:08] <EricTheHun> So help me whatever
[23:35:40] <jetlag> There's nothing like asking a question and getting it answered.
[23:35:50] <imho> Had not heard that before.
[23:36:12] <EricTheHun> Like one attorney said of me, 'Eric knows a lot about stuff no one can correct him on.'
[23:36:22] <jetlag> hehe
[23:36:40] <EricTheHun> It's just the authority in my voice, right?
I think it is because too many people cannot spell barrel.
barell, barrell, etc. etc. I have no idea where they got two "B"'s from... Anybody know? Webster's doesn't show complete entimology.