The 40-year-old was hit in the shoulder with a live-rifle round discharged by a garda marksman after he emerged from a barricaded house firing at gardai.
Members of the Emergency Response Unit opened fire on the man as the siege in a cul-de-sac in Gort, Co Galway, reached a dramatic end shortly after 8pm.
Anthony Burke (40) was undergoing emergency surgery at University College Hospital in Galway after being rushed there by ambulance after the shootout.
While gardai said they understood his condition to be stable and his injuries not to be life-threatening, a hospital spokesperson said he was "critical".
The siege at the two-storey house in Crowe Street had earlier appeared to be nearing a peaceful conclusion when Mr Burke finally responded to repeated garda invitations to talk at 5.50pm.
He began to speak with a trained negotiator. The conversation continued to the point where he surrendered one of his shotguns at 7.30pm.
But without warning, he emerged from his home at around 8.20pm and fired a number of shots.
It is understood he fired two shots at street lighting before taking cover behind a car, where he reloaded his weapon.
He was challenged by gardai but ignored their requests to put down his shotgun. He then fired at least one round towards members of the Emergency Response Unit.
Gardai then shot a number of non-lethal "beanbag" rounds - which are designed to disable - hitting him at least three times.
But the rounds did not deter him. When he continued to act in what gardai described as a "threatening manner", a garda marksman discharged a live round from a .308 rifle.
The shot struck Mr Burke in the chest/shoulder area and he fell onto the road.
Gardai attended to him quickly and an ambulance which had been on stand-by throughout the day rushed to the scene."
If you come out of a house shooting at Gardai chances are they might shoot you. And to all the fuck-wits bleating on about 'they should have shot him in the leg' I would say 'maybe they should have sent him a bunch of flowers and a fucking note asking him to stop shooting at them too!' Idiots.
Right, just enough time to grab a shower after yoga and head for late lunch/early dinner of lobster.