I have 2 model 11 VT and a model 10 T all bottom release that I use in 2 different XLR Element chassis’s. They work fine. The only trouble I have is with the bolt release. There is enough room in the trigger slot that I can use a golf tee to slide the release back and remove the bolt. I have a stealth and a mdt lss but neither of them have the opening in the trigger slot to do the same thing.