Thanks SWThomas.
Maybe the breechplug on the Triumph I was handling had a problem. It did only take about a quarter inch turn but it had to be lined up and the rubber o-rings seemed to hold it in place a little tight. Then you had to line it up again and push it in to seat it. It was a little hard to turn once seated and the barrel will not close until it is turned enough. The Pursuit that I was handling seemed easier as all you did was just unscrew it and screw it back in with no effort at all.
GZ