Jent is correct. At most clubs shooting five stand, it is acceptable for a shooter to put shells into his gun any time after he has shot his station, in preparation for his next turn. When properly run, five stand happens pretty fast. All loading, preparation to shoot, and ejection of shells is done with the barrels over the front of the station.
They should be. I see that [pre-loading] on 5-stand too & with frequency as being treated as acceptable. Loading a gun does not take long if you are familiar w/it. I'm not aware it is a rule one has to pre-load, but as Russ used to say, I could be wrong. Its common in ATA trap & we can see the results sometimes imprinted on the back of trap houses, 'nuff said. Some shooting disciplines do not allow release triggers.
To answer Jent's, inquiry, I was speaking primarily to skeet or field situations, but in the specific 5-stand situation noted, it is a clear reason to insure safety above all and I would have called the shooter out and had a discussion then and there and NOT allowed him to load his gun until it was his turn to shoot. Are you gentlemen suggesting it better to score the 'unintentional' shot into the ground as lost &/or just go on shooting or ..? The OP asked for our opinions; I merely stated mine.
As you gentlemen know, some flyer and helice rings have a two shot rule on the last bird to insure the shooter cannot turn toward the onlookers w/a live round still in the gun. Harder to tell w/a semi auto, but that muzzle better be pointed up and the trapper shown an open chamber as the shooter turns to leave the ring.
I shot sporty clays yesterday w/a number of people and one person required constant reminding by another individual to open his gun after shooting the last pair and turning around to leave the cage. Stuff happens, but no one wants to see a shooting incident & I remain of the opinion that unsafe is unsafe and that there is no excuse for an accidental discharge or indiscriminate gun handling. Not loading your gun until on the station and getting ready to shoot has been a NSSA rule seemingly forever. I think it a good one. There are stories of trap shooters shooting themselves in the foot. I have a friend who was shot by another shooter on a bunker because of a gun being loaded before it should have been and I'm not speaking of someone who wasn't familiar with their gun.
Your comment about time taken on a skeet field is not unappreciated, Jent. Makes you wonder sometimes doesn't it? Ha! I was shooting w/a long time friend until recently who because of some physical issues would take sometimes the better part of an hour to complete a round. No one else was willing and I could have cared less, a friend is a friend and as long as he was able, I was willing. We shoot at a private club, so it wasn't interfering w/anything for us to do that mid week. And his last hundred registered skeet targets a year ago while he was still able to get about a tad faster were accommodated by both shoot management & several people, myself included, who found it an honor to squad with him for that last hundred targets, time taken be damned. He only has a few hundred thousand registered skeet targets to his credit and was a fine bird shot, dog man & hunter in times past.
Back to safety; I'm of the opinion it needs correcting anytime an unsafe practice is witnessed & that would include myself being taken to task for an infraction. One does not need be impolite to do that.
Best, tw