For the record, AFAIK the rail is a more or less standard Anschutz-ish size? I've found various Anschutz and other brands of goodies over the years that fit the rails on FWB's (and some HW 55's). These can be great fun to goof about with.
How are you going to utilize the swivel? I have one that came on my Marlin 2000L. I never used it for anything. It might fit my 300S. What is the purpose of them on Target rifles? The Marlin was offered as a biathlon rifle and I always thought it was for carrying the rifle while skiing
It's for a traditional target sling, which mounts to a single point on the front of the gun, and is adjusted around the upper part of the shooter's forward arm, thus adding a very solid third point of support. Back in the day a fixture for military and hunting use. Often made so that they can also serve as a carry sling, with a detachable rear anchor point.
When mounted under the fore end, it's also literally a hand stop, i.e. a reference point to place your forward hand.
Here's an old Anschutz rig stuck on an HW 55. There are some good videos out there showing how to set the sling up properly, but it's a bit of a black art I haven't mastered yet!
It's for a traditional target sling, which mounts to a single point on the front of the gun, and is adjusted around the shooters forward arm for a steady hold.
Thanks Mike. I wondered how you could utilize a sling for off hand support without a swivel on the butt. I may have to try that. Might help me manage the weight of the 300 S. A little better