300 Blackout Pistol Project Part Deux

A few months back I mentioned I was embarking on a 300 Blackout pistol project. It’s been a slow going project for a variety of reasons, but I have made some progress and figured it was time for an update. So, here we are.

The first thing I did with this pistol was pick up a red dot sight. This was essential since the Palmetto State Armory pistol did not include any sights whatsoever. While there are plenty of high quality red dot sights on the market to choose from, I decided to slap an Aimpoint Micro T-2 on it.

Next step was sourcing some ammunition. Given my goal is to run this little pistol suppressed, I decided to look for some quality subsonic 300 Blackout ammo which has still been hard to find and expensive even though it appears the ammunition market conditions have been improving lately. It took a little while but I was able to source a case of Hornady TAP with 190gr SUB-X projectiles at a fairly reasonable price.

Since the ammunition procurement was slow, I couldn’t help myself from customizing the pistol a little bit. I picked up a fun sling and brace strap from the good folks at Warhorse Concepts to give the pistol a little flair. Not to mention I think it’s a good idea to have a way to safely retain an AR pistol in a hands-free manner. The other thing I decided to do was to acquire and install a Mod2 M-LOK hand stop from SLR Rifleworks.

Once the procurement and configuration process was complete, I finally took the pistol to the range for a reliability check and to zero the dot. The first trip was disappointing as the pistol had problems cycling the subsonic ammunition. The process was consistent. I charged the pistol and pulled the trigger. The pistol fired the round, ejected the case and failed to pick up the next round. I then charged the next round and the cycle continued. In hindsight, I wish I would have picked up some less expensive supersonic FMJ ammunition to test as well. Regardless, I left the range, called PSA, and sent off the pistol for warranty repair.

To PSA’s credit, they were very easy to work with and were prompt to respond. The repair process was fast and I had the pistol back in my possession within less than two weeks from when I shipped it to them. I was a bit disappointed that the repair notes indicated that the pistol was only test fired with supersonic loads and not subsonic ones.

While waiting for PSA to repair the pistol, I procured some 125gr FMJ loads from Freedom Munitions. I used these to attempt to confirm reliable operation shortly after receiving the repaired pistol. The results were much better, but I still had some failure to feed problems that resulted from spent primers popping out of the spent case and getting stuck in the lugs. It’s hard to say if the source of the problem was the pistol or the value priced ammunition.

So what’s next? At this point, I want to acquire some higher quality supersonic FMJ loads and retest reliable function so I can isolate the firearm or the ammunition as the source of the last set of malfunctions. From there, it will be either another repair request or confirming reliable operation with the subsonic loads prior to making any additional investments in this project.

What additional investments am I considering? Next on the horizon will be attaching a suppressor to the pistol which will require a different hand guard and a suppressor compatible muzzle device. After that, the focus will shift to getting the pistol running reliably suppressed. Beyond that, I’d like to upgrade the trigger. However, all of these changes are contingent on getting the pistol running reliably in its current state.

Stay tuned for Episode III coming soon to this blog.

Update (11/9/2021): Folks thinking about getting into or who currently own an AR pistol outfitted with an arm brace should be aware of the potential ATF regulation changes that may reclassify this type of firearm as a short-barrelled rifle (SBR). If this happens, this type of firearm will be regulated under the National Firearms Act (NFA) and will require owners to take action in order to lawfully continue to possess them. To the best of my knowledge, these actions may include, but not limited to, surrendering to braced pistol, permanently removing or altering the brace so that it cannot be reattached, removing the short barrel from the firearm and install one that is at least 16″ in length, destroying the firearm, or registering with the ATF in order to convert it to a legal SBR. I consider it to be prudent to consult with an attorney and have an action plan in place in the event that these regulatory changes take place.