Everyone loves to make things go boom. Fact of shadowrun.
The cheapest and most available explosive in the core book is commercial explosives, a rating 5 packet of boom that'll set you back 100 nuyen per kilogram. considering how effective explosives are against barriers, that's effective against everything up to concrete (heavy structural materials) in the hands of anyone with even basic training.
However, the other use for things that go boom is to set traps, and that is where the explosives rules fails.
Assuming 1 hit, how many kilograms of commercial explosives do you think you'd need to get the equivalent boom to an explosive grenade?
Somewhere between 8 and 9 kilograms.
Ok, that's rather a lot. So how about just buy some better boomdex than the cruddy commercial stuff? Well, the rating 15 explosive (+1 damage for one hit on the demolitions check) is going to set you back about 1,500 nuyen a pop to the grenade's 100 and good luck getting it during character generation.
This wouldn't be so bad (Grenades gib, bombs breach [I love alliteration]) except that since there's no listing for grenades on the barrier table, and strapping a grenade to a barrier probably qualifies as putting an explosive next to it, grenades outclass every explosive in the game in cost/benefit ratio by a truly staggering margin, are far easier to get your hands on, AND come with a built-in wireless detonator (which would set you back an extra 75 nuyen with conventional explosives).
However, let us assume for a moment that grenades do not get the X2 damage rule for explosives and merely use their own damage value. Let us also assume that you cannot increase damage from grenades use for demolitions with the demolitions skill. They are still equivalent to a rating 8 explosive with detonator for a fraction of the price AND can be used effectively as, you know, grenades!
Is it just me, or does the explosives section need a little bit of a rehash to avoid being completely redundant?