Disclaimer: I have no clue about the purpose of such convertation, but it looks so tacticool. And i’m not happy with concept, including HK-type hook and D-ring, so the concept of APRS was born.
This concept is not supposed to re-invent the wheel. Neither – to compete with big players to win the market. Idea is to add a drop-in accessory to your already existing two-point sling which settles seamlessly, appending new feature.
Any COTS sling could be used with plain ends, ready-made length adjustment.
In fact, the APRS is not a full sling, but a kit of front and rear adapters. They can be made with 1) Fastex® attachment, and 2) quick-detach swivels (preferrably).
Front adapter is marked with blue dot, and rear adapter with green dot. Orange dot resembles an attachment to buttstock, variable depending of stock type.
The key is rear adapter, green dot. It has 1) an essential connection with the main sling, 2) an essential connection with the butstock attachment and 3) part-time connection with frontal part of main sling, to convert two-point sling into one-point. The 3) is “mother” side of fastex or QD, sophistically integrated into adapter to create no noise. No proprietary swivels, no rare hardware.