“Free Fire” is a nice break from the mainstream-targeting fare that’s consumed the theaters over the past few weeks, and it even provides an impressive cast for a meager $10 million budget.

What it lacks in special effects, story arc, character development, or objective cinematic quality, it makes up for in bullets — lots and lots of bullets. Fortunately, every character is carrying pockets full of ammo to keep reloading and firing all over an abandoned warehouse.

Set in Boston in the 1970s (although there’s nothing to indicate Boston on screen), a pair of IRA members (Cillian Murphy and Michael Smiley) are attempting to procure guns from a couple of quirky gun runners (Sharlton Copely and Babou Ceesay) with the help of a pair of confusingly present mediators (Brie Larson and Armie Hammer). The unreliable hired muscle inevitably causes a suddenly escalated conflict, and a shower of shelling ensues.

“Free Fire” is gonzo action that elicits serious cinematic nostalgia, and it works purely because of the setting. Using .38-caliber pop guns makes this film more like classics (“The French Connection,” “Serpico”) than the modern gunfight films like “Smokin’ Aces” or “Heat.” Everyone gets nicked up in the kerfuffle, and it almost develops a dark comedy feel more than an action film due to the sheer volume of gunshot wounds and the persistent aggression.

Director Ben Wheatley, who wrote the screenplay with his wife, Amy Jump, does a pretty commendable Joe Carnahan/Guy Ritchie impression, and the sharp, crude dialogue moves along the action at a pleasantly brisk pace. The characters are written with a shallow generic stereotypical quality, and I was a little dismayed that we never got to know any of them beyond their respective obscenity of choice and personal vices.

Cillian Murphy, Armie Hammer and Jack Reynor carry the film strongly, while Brie Larson stands by simply looking pretty with very few lines of dialogue. Sharlton Copely stands out like a sore thumb as the flamboyantly overdone Vernon, who is given some of the more humorous lines, complete with his unmistakably thick South African accent, but he never really fits with the tone or vibe that the director has created.

Although highly stylized and undeniably gimmicky, “Free Fire” holds your attention extremely well. The action starts early, and doesn’t let up until the very end, with quick camera rotations between characters and some commendable choreography. 

One thing I couldn’t get behind was that there was little continuity of alliance. The gunfight also manifested some general rules of gentlemanly sport, but there was a mixed communication of what was acceptable behavior; shooting in the back? Holding fire to reload? Helping a downed friend? Sometimes. Also, most of the characters were just a bit too cool under the pressure of impending death. I get that the mood is light, and the levity of humor has to supersede the realism, but it lost a bit of engagement in the process.

All in all, I was moderately entertained by “Free Fire” and the characters created. I wasn’t disappointed as there is a relatively low expectation from the start in this theatrical dead zone leading up to the start of the summer season (“Guardians of the Galaxy, Vol. 2” on May 5). If you’re looking for something fun, this will suffice, but don’t expect more than a good old fashioned shoot ‘em up.