The hole spacing on all H&R/NEFs is the same, and it looks to be the same on those, better buy it, they only have one! You can get the H&R rails direct from H&R for $16 shipped or $21 shipped with a hammer extension. The H&R has more cross slots tho, although they can be cut with a file or dremel.
Tim
http://hr1871.com/Store/default.aspx(866)776-9292
