For the TL;DR crowd, this was a positive experience. The warranty process was simple and resolved my issue.
Earlier this year I was participating in a sporting clays event using my Remington Versa Max. If you haven't shot in one of these events before, they are often 10 stations with 10 clay targets at each station. Around 75 clays into the event, my Versa Max suffered a failure. The charging handle disconnected from the bolt and flew off and away during the cycling of the action after a shot. We looked for the charging handle in the long grass, but it was never seen again.
A reasonable question might be whether the charging handle was completely and properly installed into the bolt. You'll have to trust me that it was (it was). Some shooters had suggested that the spring behind the ball detent may have failed, releasing the charging handle retention mechanism. It hadn't. The failure seemed odd to me, and still does, but I've read about this happening to other people with many different makes and models of shotgun that share a similar charging handle retention design.
In addition to the charging handle, one of the four receiver plug screws was no longer present. This was quite odd, since it was directly in the sight line when mounting the shotgun. I hadn't noticed it working lose and protruding, as you might expect that it would if it had worked lose over time.
I contacted Gravel Agency and submitted the paperwork for a warranty claim. They mailed me a replacement charging handle and a replacement receiver plug screw, which arrived quickly (shipped to me, in Ontario). The replacement charging handle was different than the original, but seemed to install appropriately and I actually like it more than the original. It's closer to the style on the Pro Waterfowl model, although not exactly the same.
I am happy with the service I received from Gravel Agency, and I wanted to share that. Thank you to Gravel Agency for making this a positive experience!