I like Hackmaster 4th for a lot of reasons, not the least of which is it is really 1e with stuff [another reason is the amazing GM screen). But I and my kids love the spells, too. In my 2e campaign one of my sons plays a fire elementalist called Ember. He wanted to have the entire huge list of Fireball variants from Hack4 but some of them are a bit - over the top. He did his own versions of a few of them (with my help) and here is one of his favorites for outdoor adventuring.
Range: 5,500 yds.
Area of Effect: 10' diameter sphere
Components: V, S, M
Casting Time: 5 seg
When cast the spell hurls a tiny point of flame at great speed towards its target and, once it arrives, it detonates into a relative small but hot Fireball doing 1d4 points of damage per level of the caster; a successful save vs. spell reduces this damage by 1/2. At ranges of less than 100 yds this spell otherwise acts in all ways like a Fireball spell.
It is, however, capable of striking foes much further away. With a line of sight and no obstacles Ember's Firestrike has the potential to cause damage up to 3 1/8th miles away.
Note that at sea or on flat, level terrain the horizon appears to be about 3 1/8th miles away for a human male of average height.
For any target area past 100 yards the caster must roll 'to hit' vs. A.C. 10 as if performing a melee attack as a fighter of the caster's level. There is no penalty to this roll within the first 500 yards but the roll is made at a -1 for each additional 500 yard to a maximum of -10 to hit for targets between 5,001 and 5,500 yards away. At 5,501 yards or more Ember's Firestrike dissipates.
Example: Ember (11th level) and his henchman Firewing (7th level) are defending a mountain pass from an orcish army. The vanguard is 600 yards away and the leader is a mile (1,650 yards) away. Firewing targets the vanguard, Ember the leader.
Firewing's target is more than 500 yards away but less that 1,000 so he rolls to hit vs. A.C. 10 with a -1; he rolls a 15 and strikes the area he aimed for doing 7d4 damage vs. all the orcs in a 10' radius.
Ember's target is more than 1,500 yards away but less than 2,000 so his to hit roll is at -3. he rolls a 19 and strikes the leader and all other orcs within 10' for 11d4 damage.
Misses are resolved as grenade-like missiles with distances of scatter in tens of feet.
Example: Although the death of their warchief has shaken the orcs, they press on. Ember launches another Firestrike against a cluster of shamans directing troops from the rear - they are 2,100 yards away, giving Ember a -4 to hit. He rolls a 5, a miss. He rolls a d8 to determine scatter direction: 4, or towards Ember. He rolls a d6 to determine scatter distance; 3, or 30'. The Firestrike detonates at 2,090 yards directly between Ember and the shamans, doing 11d4 damage to a lone runner carrying orders to the front lines.
Feel free to use the spell in your own games, please just keep Ember's name associated with it. It will be in my upcoming book Far Realms, as well.