We haven't got any stamps back in a while now. I'm guessing it's been over a month, but that's just off the top of my head (I'm off now and I can't check at the moment).
In the last several months we've seen two main changes: First, wait times are going up drastically. Second, forms are being approved but it's taking them up to a month or more to send them back to us. At least once a week I get a call from a customer who says he contacted the NFA branch and they said his Form 4 was approved and he's wondering why we haven't called him yet. It usually takes me several minutes to explain that no, we didn't forget to call him and no, the ATF probably didn't lose it; the NFA branch is just taking a longer time than usual to both approve the forms and send them back.
Twice now we've had customers who called the NFA branch, were told their forms were approved, called us and found out that we didn't have them yet, and then filed with the ATF for replacement of lost forms. The ATF then sent us a certified copy of their Form 4 (a copy that doesn't have a tax stamp on it) that replaces their "lost" Form 4 so we can release their NFA item to them. And in both cases, their actual "lost" Form 4 with the tax stamp on it showed up in the mail a few weeks later.
I really wish people would stop constantly calling the ATF and requesting a status on their forms. And if they are told their form is approved I wish they'd give it a month or two before they start asking the ATF for a replacement form. All that does is slow down the system for all of us.
It's pretty simple: There was a HUGE increase in forms sent in to the NFA branch as everyone tried to get in before the 41F change. I know I did; before 41F was finalized in January I was worried I'd need a sign off that was impossible to get. And after 41F was finalized I knew I had to get in before the deadline because my wife is on my trust and she refuses to be fingerprinted or photographed for my next NFA item.
The Form 4 for my last NFA item (my Mask HD) was sent off on December 11th and was approved exactly four months later on April 11th. And it took less than two weeks for them to send it back. Now, we haven't seen anything come back from after the last week of January. I submitted the Form 4 for my LMT SBR in the first week of February and I'm still waiting. And wouldn't be surprised if I had to wait a while longer.