Got a question concerning a few dimensional details on a MP5K recoil assembly.
On the SW5 PDW bolt carrier that I have, the recoil spring "hole" is .533 inches ID.
On a POF MP5K bolt carrier, the recoil spring hole is "stepped" with a .485 inches ID at the end and .508 inches about 1/4 inch in.
The recoil spring assembly spring retainer "plastic" piece on the SW assembly is .503 inches OD.
As you can determine, the SW recoil spring assembly fits in the SW bolt carrier, but not on the POF bolt carrier.
Does anyone have a HK recoil spring assembly for a MP5K or SP89 that they can measure the OD of spring retainer plastic piece? Just want to make sure that I order the correct replacement recoil spring assembly for the POF bolt carrier.