PPA_FTW So, you're going to have a few issues, SB Tactical's HBPDW will fit but it will not retain the the pin and spring for the rear takedown pin. Your brace will not collapse with the original SL-15.
I however edited the SL-15 to be compatible with the HBPDW brace. In doing so I lost the hose clamp which severely weakened the design, so I'm thinking about designing a way for the hose clamp to be added back.
