Posted 10 May 2017 Receiver rail flattening jig from HKparts ($250 new) https://www.hkparts.net/shop/pc/viewPrd.asp?idproduct=1699&idcategory=0 I never used this, the LSC flats didn't need it. $150 + $10 shipping Apopka, Florida, United States Share this post Link to post Share on other sites