Grease Gunner
Well-known member
While I was working on some PTR9-SD conversions for fellow forum members today, I decided to dig out an old Special Weapons MP5K receiver I have had laying around for awhile and play around with it…since I had the SD welding jigs kit figured why not.
I had to replace the shelf that was on it as someone really jacked that up, replaced the 3 lug barrel with an RCM SD ported barrel, and rewelded the trunnion in as that was a hodgepodge of cluster f@@k. I had to shorten the suppressor cage by 3/4” and welded the front ring back on. I also cut down an old/beat up SD handguard I had laying around too.
I still have to fix the magazine release hole as it’s in the wrong spot, but I’ll get that sorted out soon. Im also waiting on the K “stiffeners” for the back end of the receiver to come in too. I put it all together and fired 5 shots by dropping the rounds into the chamber and it chambered, fired, extracted and ejected just like it should.
I decided to use an HK SP5K bolt and carrier I have had laying around for a long time as the donor for the “guts” I had to shorten the front of the carrier to allow for it to not bottom out on the cocking handle support. I machined a ring, pressed and welded it in so to allow the recoil spring to cycle correctly.
All in all, I think it’s going to be a fun little gun. I have it setup with a TPM Outfitters 8” suppressor and it looks right at home on this little thing.
Oh and the PTR9-SD guns are ready for test fire, blast and coating then they will be out the door….just in time for the new batch of guns to come in and be done.
I had to replace the shelf that was on it as someone really jacked that up, replaced the 3 lug barrel with an RCM SD ported barrel, and rewelded the trunnion in as that was a hodgepodge of cluster f@@k. I had to shorten the suppressor cage by 3/4” and welded the front ring back on. I also cut down an old/beat up SD handguard I had laying around too.
I still have to fix the magazine release hole as it’s in the wrong spot, but I’ll get that sorted out soon. Im also waiting on the K “stiffeners” for the back end of the receiver to come in too. I put it all together and fired 5 shots by dropping the rounds into the chamber and it chambered, fired, extracted and ejected just like it should.
I decided to use an HK SP5K bolt and carrier I have had laying around for a long time as the donor for the “guts” I had to shorten the front of the carrier to allow for it to not bottom out on the cocking handle support. I machined a ring, pressed and welded it in so to allow the recoil spring to cycle correctly.
All in all, I think it’s going to be a fun little gun. I have it setup with a TPM Outfitters 8” suppressor and it looks right at home on this little thing.
Oh and the PTR9-SD guns are ready for test fire, blast and coating then they will be out the door….just in time for the new batch of guns to come in and be done.
