Trap gun for a beginner

Thanks guys. Lots of wisdom shared. 20 gauge is not an option. He is big enough to do well with my A5 12 gauge. I offered a 20 gauge but his coach wants them to use 12's. I did a search and found stock options for the 1100/11-87 and 870. Also the CZ trap gun is attractive. I do have a Berretta 686 Onyx but he doesn't want an O/U. He and my son are a little stubborn like me and will only shoot what they want, limiting options.
Thanks again for good advice.

As a fan of the 870 Wingmaster/FieldMaster, and seeing as an auto runs itself, a pump is a good first field shotgun.

And target loads are just as easy on the shooter.
Went to two diff clubs and saw youth shooters running Remington and Beretta autos.
Ive thought about a 12 ga crossover Citori.
As bad as I shoot, seems like a waste of money LOL
There’s some nice 870 Trap guns out there with a couple hundred thousand rounds left in them. BT99’s are nice for new young shooters. Less to keep track of on the line, drop a shell in, close it, shoot, open, repeat. No safety, no slides, no problem.
Great gun, but there are a thousand BT-99s out there for every BT-100, and available in many more configurations. (Max, Golden Clays, 80/20, Micro, etc.)
I coach high school trap. I am not a regulation trap shooter but I am a fair shotgunner. Shot more skeet and sporting clays.
I mainatain loaner shotguns in a high poverty school district that believes financial status should not limit student participation. I see a little of everything including students that show up with no ppe and no shooting experience at all.
I have 20 and 12 gauge 870s for loaners. I get a lot of questions from parents and I always recomend they start out simple. The gun won’t lose value and even if they move up they have something they can use for generations.
I’ve seen 14 year old females turn away from shooting because dad or uncle or step-dad got them a heavy 12 that knocked the snot out of them.
Safety first, proper stance and mount, one on one instruction is key. These kids don’t want to be embarrassed.
I should add that I’ve seen some of these petite little 14 year olds go on to be pretty competitive shooters with proper introduction.
Last year we had one who asked me if she could go back to the 20g loaner. Her father bought her a cheap 12g because he thought she needed it to be competitive (worst factory trigger I’ve ever seen). She tried but she and her scores suffered.
They have to be safe.
They have to have fun.
Then they can be competitive.
I was coaching one young lady who's father insisted she use the 26" Citori he'd learned to shoot. It did not fit her, and was kicking her to the point she was afraid of the gun. Her scores started at 10/25, and plummeted. I kept asking if he had another gun, or if he'd aĺlow her to use one of the many us coaches had available. No dice. She was to learn on the gun he did. When his daughter shot a 0/25 and walked off the line crying, he finally relented and let her shoot his A303. She shot a 15/25 that first round. By the next week she was right up there in the top squad, with her dad eating a lot of crow for a while.
I give her all the credit in the world for hanging in there, and especially for still being willing to shoot after that zero.
A friend is an avid pheasant hunter and will shoot a little trap before hunting season. One round and a rest before another is about all the fun she wants with her Benelli Ultra Light.
Get the Citori or BT99.

Do NOT get a 20 gauge.
My reply is specifically for the original poster and not as a general recommendation for something to be use by an entire student body at the local high school for generations. If you really think your situation calls for less gun for a year, get the inserts you can use to shoot smaller shells in them for a year.

You can do that with a BT99 or a Citori but not in the pumps or semi-auto guns and an added benefit is in the heavy gun it really will deliver less recoil.