From the US's perspective, a 4457 doesn't expire, but my 4457 on the rifle I plan to take in July states that it's "Expiration Date" is 9/30/2022. Do I need to trek down to customs to get a new one to get a Dutch permit to transit through Amsterdam?

the new on you can print off the Customs web site does not lit an expiration date so get a new one

Do get a new 4457,

Thanks for the input. Glad they finally took the expiration date off of it. Maybe this will be the last time I have to get a new one.

Got my Dutch permit in record time this year. Couple >of weeks at most. Even before I provided the new 4457.

One useful thing from the Customs guys. They told me if I just needed a new 4457 with no changes, I didn't need to bring in the rifle, just the old form and they'd renew it.

call Customs first to see if you can only bring the old form, each agent has their own idea of the rules