GOBLIN SWARMS!!!!!!!!!!

I would remove "Battle Hymn" as you don't have any spell which could benefit from a huge amount of mana, and you neither have carddraw to give you enough handcards you could play.
You could either increase the number of "Goblin Chieftain" and "Goblin Wardriver" or change to another card.

Some suggestions, based on my monoR Goblin deck (http://www.mtgvault.com/muktol/decks/monor-tribal-goblins/)
Quest for the Goblin Lord ({R}; enchantment; whenever a Goblin enters the battlefield under your control, you may put a quest counter on Quest for the Goblin Lord. As long as Quest for the Goblin Lord has five or more quest counters on it, creatures you control get +2/+0)
Spikeshot Elder ({R}; 1/1; {1}{R}{R} (no tap!): Spikeshot Elder deals damage equal to its power to target creature or player), Warren Instigator ({R}{R}; 1/1; double strike; whenever Warren Instigator deals damage to an opponent, you may put a Goblin creature card from your hand onto the battlefield), Mogg War Marshal ({1}{R}; 1/1; echo {1}{R}; when Mogg War Marshal comes into play or is put into a graveyard from play, put a 1/1 red Goblin creature token into play); Furystroke Giant ({3}{R}{R}; 3/3; persist; when Furystoke Giant comes into play, other creatures you control gain "{T}: This creature deals 2 damage to target creature or player" until end of turn)
Infiltration Lens ({1};{1} to equip; Whenever equipped creature becomes blocked by a creature, you may draw two cards)

I hope I was able to give you some ideas
Greetings
Muktol

Good stuff.

I agree with Muktol, Goblin Chieftain is too good of a card to not be running 4 copies.