Would it be ok canon-wise to have a Space Marine Chapter use Basilisk artillery fitted on let's say the Rhino chassis in the case of a Firstborn Chapter or fitted into a Repulsor hull in the case of a Primaris Chapter?
Is there any other conventional tube artillery systems that could work for the Space Marines?Yes and no.
The marines aren't banned from having conventional tube artillery, and in fact in the legion days they had basilisks of their own. They stopped using them because basilisk artillery is unsuited to post-heresy marine doctrine. It's too slow, has a massive logistical footprint (needs more crew, separate ammo carriers, etc) which makes even slower, and designed for mass bombardment instead of the precision fire support that marines need. But if they decided all of that didn't matter and what some basilisks, they could still use them.
Is there any other conventional tube artillery systems that could work for the Space Marines?
Ah ok, so it's not the concept of tube artillery that's incompatible with Space Marine doctrines and tactics, but the fact that 40k tube artillery doesn't have those advances current rl SPG tube artillery has which would make modern day artillery fitting for SM doctrines / tactics when the likes of Basilisk will not fit SM doctrines and tactics.Something like the the US army's prototype Crusader SPG, that could move and fire while drawn from it's own internal ammo storage, with the ability to fire multiple shells at varying trajectories timed to hit the target all at the same time might be useful, but the imperium doesn't have one of those, their tube artillery is very WW2 in design.
Some old chapters could still have these:Is there any other conventional tube artillery systems that could work for the Space Marines?
Some old chapters could still have these:
Typhon Heavy Siege Tank - Warhammer 40k - Lexicanum
wh40k.lexicanum.comMorbus Heavy Bombard - Warhammer 40k - Lexicanum
wh40k.lexicanum.comArquitor Bombard - Warhammer 40k - Lexicanum
wh40k.lexicanum.com
Indirect fire assault guns being interchangeable with artillery is very much a RL thing, at least for WW2.Those aren't quite tube artillery. The Typhon is a assault gun, and the bombard is something we don't really have a RL analogue for but it's basically an indirect fire assault gun.
High caliber mortars on vehicles are also a thing IRL.The maximum elevation angle of the ZiS-3 was the highest of all Soviet self-propelled guns. The maximum indirect fire distance was nearly 17 km. SU-76Ms were sometimes used as light artillery vehicles (like the German Wespe) for bombardments and indirect fire support. However the power of the 76.2 mm shells was not sufficient in many cases.
Is GW releasing something new, or just re-boxing stuff?
The SpecWeaps box look kinda reasonable actually. <$1 per bit is decent. Heavy weapons...maybe worth it.Unfortunately to get special and heavy weapons for the Mk6 armor...you have to buy separate plastic box sets.
$42 gets you 20 heavy weapons and arms. Plus extra scanners. 10 missile launchers, and 10 heavy bolters.
$42 gets you 60 special weapons. 10 each of flamers, meltaguns, plasma guns, rotor cannons, volkite calivers, and volkite chargers.