Don't know squat about the Victor brand, but it's probably a Chinese machine, or perhaps Taiwanese, which would be better. Plenty heavy for gunsmithing use; I know Grizzly has been selling 16x40 gunsmith lathes for years, but as solid as they are, they're also very heavy, as are chucks for a 16" machine. It's a PITA to swap chucks when they get this big & heavy, and the bigger chucks are also considerably more expensive than those for a smaller machine, like a 13" or 14" lathe.
I've got a couple of 2000+lb lathes sitting on the concrete floor in my garage; when Dad built the garage, putting heavy machine tools in it wasn't a consideration, so the concrete is only 4"-5" thick, which means I've got to check the ways with Starrett machinist levels periodically because they settle on such thin concrete. The 16x40 lathe in the photo you attached will likely weigh at least 3000lbs - it'd benefit from being set on a pad at least 8" thick.
On the plus side, having a lathe that large would allow you to work on bigger stuff than I can do with my 13" & 14" lathes - when you get into a machine with a 16" swing, you're starting to talk 'heavy duty'. It's way more lathe than you'd ever need for gunsmith work, but hey - if it's not that far from where you live, and the price is within your budget (remember, you'll need a 4-jaw chuck, QC tool post, and a bunch of tool holders for it - and this stuff is all more expensive than the same parts sized to work on a 13" or 14" machine), then it's worth a look.
Hold the phone! Just noticed that the ad states the lathe is a metric model - that means no inch markings on the dials. Also means the lead screw for threading is metric, which would make cutting inch threads a PITA.
