Pierce Brosnan and Samuel L. Jackson seem delighted at the prospect of filming a B-Western together in “The Unholy Trinity,” a mediocre genre piece with the occasional entertaining sequence or moment.

Well, I’m pretty sure they share the frame together once or twice in this good-looking, handsomely mounted indie. The way these things work, often you can’t afford to have both stars on the set at the same time. As they’re sometimes joking with each other, and at other times threatening or shooting at one another, they both don’t have to have been there for those one-shots and close-up scenes to edit together.

It’s the sort of Western you get when two Aussies who perhaps enjoy the genre — one who directed the most recent underwhelming version of “Robert the Bruce,” the other a screenwriter with no credits that have crossed the Pacific to any sort of notice. The Montana locations, fights, gallops and shootouts look right. But there’s no “feel” for the story that makes sense.

Not everybody’s Tarantino and gets a pass for a Western that lets Samuel L. cut loose with assorted anachronistic”mutha” this and “my Black ass” that variations, after all.

A condemned man (Tim Daly, unrecognizable) makes his estranged son (Brandon Lessard) promise to “avenge” him for being “framed” by a dirty sheriff just as the priest (David Arquette) leads him to the gallows.

It’s 1888, the year before Montana became a state. And here’s the young man, who bears an unfortunate resemblence to longtime “Drunk History” host Derek Waters, trekking across the territory to a town called Trinity with a small pistol and a brass urn with his father’s ashes.

Montana was ahead of the curve in that choice for burials, at least in this Aussie version of Western America history.

The kid gets the drop on the sheriff in the Trinity church. But the aged Irishman behind the badge (Brosnan) is sage and cagey and the WRONG sheriff. A cleverly-staged standoff eventually straightens that out.

But the kid gets into real trouble when he gets between a “dance hall girl (Katrina Bowden) and her regular, roughneck miner-customer. Three people wind up dead, and with surviving members of the miner’s family and a Scots-born Georgian (Gianni Capaldi) baying for blood and already frustrated that Sheriff Gabriel Dove isn’t charging or pursuing a Blackfoot woman (Q’rianka Kilcher of “A New World”) for another killing, there’s lynch mob trouble on the horizon.

Another newcomer in town who refers to himself as “Saint Christopher” (Jackson) was present at the hanging across the territory at the prison, and has some connection to the dead man and by extension his son. He’s hellbent on setting the locals against one another.

Throw in more “dance hall” girls, an “actor” pretending to be a member of another ancient profession, posses and stand-offs and you’ve got yourself a reasonable facsimile of a Western.

There’s a tiny smidgen of humor, much of it provided by Jackson and a wee bit of it coming from Brosnan’s Sheriff Lucky Charms.

“The Priest?”

“I don’t think he’s a REAL priest!”

“Ah, like a Lutheran?”

Kilcher gives the picture credibility that extends beyond it’s Old West boom-town (new construction) look, and the weathered stagecoach, muddy streets and snow-dusted hills behind the action.

The shootouts are first rate, and the stuntwork does a nice job of hiding the well-past-AARP status of our Big Names.

The script may be surprisingly convoluted, with hidden Confederate gold, assorted alliances and double-crosses and a town that seems to wholly have the sheriff’s back — until they don’t.

But a bit of entertainment creeps in, much of it provided by Jackson and Brosnan, even if it turns out they weren’t one the set together for more than a day or two.

Rating: Rated R for violence, language and some sexual material.

Cast: Pierce Brosnan, Samuel L. Jackson, Brandon Lessard, Veronica Ferres, Tim Daly, Stephanie Hernandez, Katrina Bowden, David Arquette and Q’orianka Kilcher.

Credits: Directed by Richard Gray, scripted by Lee Zachariah. A Roadside Attractions/Saban Films release.

Running time:1:33