Mark 1 16" Trips' are the "2nd" Hood guns. The main set are the Duel 15" Mark 3 L's IIRC.

for 16 trip Mark 1 has better range but it's heavy and not for Hood to place 4->slow

Mark 2 is the Hood guns and lighter but short range

Not always the case

16" Trips?

The Mark 1 are the best.

marks means variant of a gun. Mark I is an 'earlier' version and the Mark II is an
improvement, be it in range, shell power, reload, etc. rule of thumb is that the higher
the mark, the more advanced it is. the pratical upshot of this, however, is that the
higher the mark, the more experienced the gunner has to be in order to man that
particular turret. basically, it comes down to this: the higher the mark number, the
more time it takes to reload, higher shell damage, and sometimes more range.

*With reference to the gunrange sheet posted on top of the Royal Navy forum subsection*

Old Gun Range => Current Name
15" Mark I L => 15" Mark I L (BB1 Guns)
15" Mark II L => 15" Mark II L (BB1 Guns)
15" Mark I RP12 L => 15" Mark III N (BB2 Guns)
15" Mark I RP12s L => 15" Mark III L (BB3 Guns)

The current 15" Mark IV L (the vanny guns) have about 3/4 of a centimeter more than the
16" Marks IV L (lion guns)

Anybody tell me how mucu more range please? are we talking great range or not?

And it has one more numeral.

above nailed most of it, but also,
since its a longer ranged gun, wouldn't it need to have a "Heavier Shell" so to speak
to have the reload more? but the gun weight is pretty much spot on, have fun
grinding the QE, fun ship ^.^

Mark II has more range than the Mark I, the said can be true for higher Mark #s.