I bought this riser from Amazon: http://www.amazon.com/gp/product/B019O40MLY?psc=1&redirect=true&ref_=oh_aui_detailpage_o04_s00
using a dremel tool and file, I had to remove 3 knobs from the hi point weaver rail for this riser to fit (really easy to do)

using a dremel tool and file, I had to remove 3 knobs from the hi point weaver rail for this riser to fit (really easy to do)