Will this fit the HK SP5 ? — 2 Answers

bolt locked back and had no idea why... my pic rail never came with loktight but midwest ended up sending me some and you basically hand tighten it but they said this is mainky for MP5 9.. version only and i sent it to h&k and they said the following... Inspected firearm. Found bolt carrier to stay in rearward position. This is due to customer installing aftermarket pic rail on top of receiver which is "pinching"
the reciever and in turn slowing/stopping bolt carrier function. Once pic rail is loosened the bolt carrier functions properly. Would suggest either removing pic rail entirely or else putting blue loctite on screw threads and tightening screws
only enough to keep rail in place, but not impede function of bolt carrier (if
possible). No other negative mechanical issues found. Function check --OK--
that is H&K response so if u do buy this becareful and do what the above says.... really sucked and never would've thought this was the issue as I never even fired it once ... hope this helps out anyone with this issue