1. Buy a case gauge.
2. Decap and size your brass.
3. BEFORE loading it, case gauge your brass.
5. Everything that fails the gauge, set aside.
6. Run the failed brass through a Lee bulge buster (assuming you don't want to drop big money for a roll sizer).
7. Wash, Rinse, Repeat.
8. Case gauge the finished round.
9. Sleep easy knowing every single round you just made will go fully into battery in every functioning and SAAMI compliant 40 on the market.
You can choose to bulge bust it all out of the gate as well if you want.
This is the way forward, if you want to shoot safe and reliable 40.
As far as your current predicament...if you have a FCD, you can try running them all through that, if it will gauge after the FCD, send it. Otherwise pull it down using any of the methods discussed here, kinetic hammer is probably the cheapest and easy to use. As another mentioned, drop and ear plug in it. I have a block of wood on my bench for this, better than constantly beating your table.
You might hear from a few who say, "I've been loading <insert huge number here> years and I've never needed a case gauge, plunking in a barrel is fine! Sure...and there's lots of people out there who've gotten away driving after 3 or 4 beers their whole life.......until they don't. There's still a few "I don't wear a seat belt because the car might catch on fire" guys left out there too, and they are fine.......until their head comes apart like a ripe melon in a 20mph wreck because some entitled snowflake was looking at his phone and hauling ass across the mall parking light to get into the line at Starbucks. Don't be the guy sitting on a thousand rounds of "plunked" ammo, who buys a new gun and realizes it is all out of spec and won't run in his new gun..because it has a tight throat, or his old gun a sloppy throat.....or even worse, you go shooting with a buddy and he shoots your ammo and it doesn't go all the way into battery, just enough to fire, and he blows the mag and mag spring into his foot. Makes you a bit unpopular.
Note: I loaded about 8K rounds of range pickup 40 last month. They were mass rollsized first. Every single round passes through a gauge block, and every single one passed. I know for certain that every single one of those rounds will go fully into battery on every single functioning 40 on the market that has a SAAMI compliant chamber.
"We don't need a tape measure babe, I have a stick that I"ve marked out". Wife: "Sure dear, but if we use that stick to measure the benches you're building, they'll be 3 inches too low for the table".