pipe bomb pressure

[serodronin]

when performing the pipe bomb method on halosafrole/MeAM, what pressure should SWIM be shooting for?  should the pipe just barely hold the aqueous contents, or should there be some open space on top?

[Osmium]

Don't fill the bomb to the top! You want a lot of head space or the pressures will be excessive.

[startinout]

Sorry to offer an alternate opinion but the volume a given area of liquid would occupy given it were a gas far exceeds any head space that would be realistic in a pipe bomb normally available to the clandastine. Thus your qustion is irrelevant.
Think  'bomb' does it really matter if  a grenade is contained in a grenade twice the size, not really to any practical extent, if we were talking a grenade the size of an automobile then I would start feeling safer if it were to be lobbed towards me (except for the instance if it were to land on me).
Anyway just a rationale counter suggestion, ignore me as you would a dissenting trouble questioner at a scientific forum, that is unless it happens to make sense to your logic

blue always
except for at the start