I would think if the o-ring was damaged or maybe brittle from age that it would definitely effect accuracy because of blow by. H&R changed to a screw in plug when back in the day a fellow dropped the hammer on a loaded one(o-ring)and only got a pop from the cap. He immediately broke open the gun and a slow hang fire happened blowing the breech plug back at the shooter... don't remember if it killed him or if he was just severely injured.
Yeah, mine has the action that does not break fully open, to "catch" the plug from being blown out. The blow by is what I had read about in the past, causing inaccuracy. I change that ring out from time to time. Have had that gun since the early 80's and have always shot 209 primers and a patched round ball. Have never had a misfire with it. I have killed close to 40 bucks with it, all within 50yrds. Funny, years ago, I sold a bull to a man from Vermont. He mainly tracked deer on snow up there, Benoit style. I had that gun down at the barn sighting in after putting a peep sight on it. He seen it and offered me $800 for it. I turned it down. Most of them up there have switched to them Woodman Arms Patriots for tracking.
