It doesnt hurt to bring a backup if you have one that fits you. Gives me peace of mind, and an excuse to shoot different guns in practice!

I have had guns jam up, wood stocks come undone, combs fall off, rounds get stuck under the ejector, and I had a gun stolen out of my locked car at the national shoot in Sparta IL at a drury inn (closest parking spot to front desk and during the 3 minutes it took me to run in and grab my charger from the hotel room)

It helps give me peace of mind that if something bad happens, I will still be able to shoot! Although if I had two guns when they were stolen..... I would be out two guns!

No, if my gun breaks one of my squad mates will probably let me shoot his to finish. Would I score as well with a borrowed gun? Maybe not. Is that going to bother me? Not really. If I can't manage a loaner, then I can walk the rest of the course with the squad, see the targets, and still enjoy the day.

For the record, If attending a shoot requires commercial air travel, I don't go.

Anything can break. At any time. When I shot a semi, I carried two, never needed the spare so left the BU in the car. Then I broke a bolt con-rod at a shoot. Buddy had a spare, soo I was back in business in no time and did not need to go back to the car for the spare. But from then on, I started carrying a spare trigger group and a spare bolt group -- they fit in my bag and were easier than carrying the 2nd gun around.

Now I shoot a K80. With a custom stock and custom barrels. And I have a BU that matches pretty darn close, also with a custom stock and custom barrel. When I started traveling to bigger shoots, I brought the BU. But it's now more of a PITA to fly with even one gun let alone two, plus now you get into luggage weight restrictions, so I take the chance and travel with just one. If it breaks, I will rent, borrow, demo (at a bigger shoot) or beg a loaner. Not ideal, but I will finish the shoot

PS: Even though my measurements are way off normal --I'm 6'-6" and left-handed-- I can somehow shoot an off-the-shelf Beretta semi pretty darn well

Don`t shoot clays competitively, but always take two guns when I go hunting. Travel too far and/or have to spend money these days to hunt pretty much anything. Always take a spare because anything mechanical can break.

For tournaments I’m typically driving 1-2hrs so I’d bring a 28” A400 Xcel as a backup to my CG. Sold the CG and got a Coles A400 pro, so now my backup is almost identical other than 2” of barrel length. For fun shoots I don’t bother if I’m solo, and if my two boys are with me we have three A400’s so we’re covered if one ever did have an issue.

Better to have and not need than need and not have imho.

I typically don't have a backup when I compete. Never found the need to carry one. Conversely, I do take a ridiculously large amount of shells with me. I can't really explain why.

I don't carry a spare but me and two other guys on my squad shoot almost identical guns and they are all three release trigger K80 30" barrels.

Yes

I never carried a spare until the last couple of years. When I
shot an O/U (MX8) I carried a spare trigger group
However thanks to old age I shoot an A400Xcel and have 2 of them. Have carried a spare but never used until this past weekend
On next to last station the screw on the bolt release backed out and did not the right size hex head to tighten back up!
Had 16 birds left to finish shoot.
Backup gun had not been shot in 3 months at least
Long story short ,15/16 with it and got a punch.
So , yes will always carry back up