Kildare man Sean Baldwin was left to rue a poor start as he finished the 50metre 3-Position shooting event in 20th place, missing out on a spot in the final.
Baldwin was 22nd after the opening series of kneeling rounds, but moved up to 19th with a good performance in the prone leg of the competition.
The Newbridge rifle man was unable to make up any further ground in the final series in the standing position as he posted a score of 1,114.30.
"I'm disappointed," Baldwin told RTÉ Sport. "Conditions were perfect but I had a bad start in the kneel.
"My prone was excellent but again in the standing I found it hard to find the 10, I was bit left and right of it."
The top qualifier, Laslo Suranji of Serbia, set a new Paralympic record of 1,165.57, illustrating the fine margins separating these elite performers, and despite Baldwin's struggles thus far at these Games, he remains upbeat ahead of Wednesday's 50m Prone event.
"Any 9 I hit today in the prone position was just a millimetre away, so I'm happy with my prone and that's coming up on Wednesday," the 48-year-old said.
"Today was my favourite event, it's the marathon event, but Wednesday is my strongest event, it's really going down to decimal points there.
"It's like golf. On the day you shoot level par and tomorrow you shoot six under. Whoever wins today might not win tomorrow. Anyone in the top 20 can win.
"I'm really shooting well in prone, but then again, so is everyone else!"
Upbeat Sean Baldwin says any top shooter can win a medal on their day @ParalympicsIRE https://t.co/NotvOKwOXp
— RTÉ Sport (@RTEsport) September 12, 2016
