This is a report on my observations and results using a standard AR lower with Endomag converted Pmags to assemble a 9 mm PCC.
I currently have four “Glock Mag” compatible 9 mm carbines. These include the KT Sub 2000, the Ruger PC Carbine, a Micro Roni with a dedicated Gen 3 Glock 19 and a 10.5” AR built on a PSA Glock LRBHO lower. Of these, the only one that I am not 100% happy with is the AR.
First, although it has been basically 100% reliable feeding ball ammo from Glock, KCI, Magpul and ETS mags, the LRBHO has only worked semi-reliably with the ETS mags. This is not a major problem as many 9 mm AR’s do not even feature a LRBHO. In addition, to prevent breaking the bolt catch, the bolt over travel must be reduced by either spacers in the buffer tube or a longer PCC specific buffer.
The second issue is of much greater concern. This is because I do not trust the gun to safely feed and fire HP ammo. Early on when working with this gun, I realized the design required the cartridge to make a large unsupported jump from the mag to the chamber. I found with HP’s it was easy for a bullet nose to catch the chamber edge and misfeed. It could also however, due to the heavy spring and buffer used in the PCC, drive the bullet deeply in to the case during the feeding cycle. This, as I learned from experience, can cause extreme over pressure and a case head failure, with many (trust me) unwanted results. One might say, just don’t use HP’s, but this seems like a terrible limitation on a defense carbine which can share your carry gun mags and ammo.
Enter the Endomag. Simply put the Endomag conversion allows you to convert your standard (Gen 2 or 3) Pmag to a 9 mm mag. Installation take only seconds and the mag’s original configuration can be restored just as fast. Just remove the mag floor plate, remove the spring & follower, then insert the Endomag conversion (one piece) and reinstall the floor plate. I ordered a 3 pack of the conversions a few week ago and last week received my new PSA SBA3 lower ($179.99 on sale!).
To test proof of concept, I mounted my 10.5” 9 mm upper on the new lower after installing a heaver buffer and buffer spring borrowed from my KS47. At the range this morning I ran 100 rounds of HP’s (50 Berry 115 gr TCHP, 50 Win 115 gr HP) and 45 ball rounds. I am happy to report 100% feeding and function. The Endomag provide an excellent feed ramp built into the longer Pmag body. They also provide very positive actuation of the AR bolt hold open catch (maybe better than the standard mags). Feeding was extremely smooth and positive. Loading the mags is also easy as the rounds can be pushed in from the top just like the standard 5.56 rounds.
Overall I think this is a very viable option for someone who wants to build a 9 mm PCC without the expense (and some of the drawbacks) of a dedicated pistol caliber lower.
Sorry this got a little long.
I currently have four “Glock Mag” compatible 9 mm carbines. These include the KT Sub 2000, the Ruger PC Carbine, a Micro Roni with a dedicated Gen 3 Glock 19 and a 10.5” AR built on a PSA Glock LRBHO lower. Of these, the only one that I am not 100% happy with is the AR.
First, although it has been basically 100% reliable feeding ball ammo from Glock, KCI, Magpul and ETS mags, the LRBHO has only worked semi-reliably with the ETS mags. This is not a major problem as many 9 mm AR’s do not even feature a LRBHO. In addition, to prevent breaking the bolt catch, the bolt over travel must be reduced by either spacers in the buffer tube or a longer PCC specific buffer.
The second issue is of much greater concern. This is because I do not trust the gun to safely feed and fire HP ammo. Early on when working with this gun, I realized the design required the cartridge to make a large unsupported jump from the mag to the chamber. I found with HP’s it was easy for a bullet nose to catch the chamber edge and misfeed. It could also however, due to the heavy spring and buffer used in the PCC, drive the bullet deeply in to the case during the feeding cycle. This, as I learned from experience, can cause extreme over pressure and a case head failure, with many (trust me) unwanted results. One might say, just don’t use HP’s, but this seems like a terrible limitation on a defense carbine which can share your carry gun mags and ammo.
Enter the Endomag. Simply put the Endomag conversion allows you to convert your standard (Gen 2 or 3) Pmag to a 9 mm mag. Installation take only seconds and the mag’s original configuration can be restored just as fast. Just remove the mag floor plate, remove the spring & follower, then insert the Endomag conversion (one piece) and reinstall the floor plate. I ordered a 3 pack of the conversions a few week ago and last week received my new PSA SBA3 lower ($179.99 on sale!).
To test proof of concept, I mounted my 10.5” 9 mm upper on the new lower after installing a heaver buffer and buffer spring borrowed from my KS47. At the range this morning I ran 100 rounds of HP’s (50 Berry 115 gr TCHP, 50 Win 115 gr HP) and 45 ball rounds. I am happy to report 100% feeding and function. The Endomag provide an excellent feed ramp built into the longer Pmag body. They also provide very positive actuation of the AR bolt hold open catch (maybe better than the standard mags). Feeding was extremely smooth and positive. Loading the mags is also easy as the rounds can be pushed in from the top just like the standard 5.56 rounds.
Overall I think this is a very viable option for someone who wants to build a 9 mm PCC without the expense (and some of the drawbacks) of a dedicated pistol caliber lower.
Sorry this got a little long.
