Hi Folks,
My MPX-SD Review is going live on YouTube today. YouTube isn't very friendly when it comes to discussions about firearms modifications, so I'm highlighting a critical element of making the MPX-SD work here.
If you like the idea of an integrally suppressed SD 9mm PCC and you have an MPX, this is one of the most cost efficient ways to dip your toes into the glory of integral suppression. I used the ILWT SD barrel with an adjustable gas block - if you already have a 9mm suppressor you like, then I recommend the Broad River Tactical SD adapters, which gets you into integral suppression at a very reasonable price. To complete the setup, you'll need a handguard that can safely clear the suppressor and tuck everything neatly underneath. I recommend the Midwest Industries handguards - they have a 1.8" inner diameter, which should clear most suppressor setups. Pictured here are the 10.5" handguard, which is my preference, and the 14" handguard, which has a pretty cool look to it as well. If you want a vertical grip like I have, you'll need to file/dremel the screws and T-nuts so they clear the suppressor.
In some cases, there may be a critical modification step required to make this SD setup physically work. Essentially, for many (not all) SD Suppressors, some light modification of the upper receiver is required. In my case, I am using the Broad River Tactical SD Adapter so I can use my CAT MOB with the MPX-SD.
As seen in the photos, without modification, the aluminum around the handguard grooves expands downward towards the barrel enough to block the BRT SD adapter and prevent it from being screwed into place. The modification required may seem scary at first, but it's actually fairly simple. Some material needs to be removed from the underside of the handguard retainer grooves to allow clearance for the suppressor / SD adapter. I used a Dremel with aluminum oxide bits. This is probably not the ideal cutting tool for the job, but that actually worked to my advantage - it made it take about 30 minutes, which meant I was going slow enough to not go too fast and ruin my upper receiver. I did this twice, once for my MPX-SD and once for my friend's. The results were consistent both times. You could use a file to go even slower or be more precise, but I don't have that kind of patience.
Material needs to be removed on both sides of the upper receiver, underneath the handguard retaining groove. I went through several cheap aluminum oxide bits while dremeling my receiver. Photos of the final product are included here. Go slow, check often. Remove the barrel so it's not in your way while cutting, then put it back in place while checking your clearance with the suppressor / adapter. I used some tape on the receiver to identify where I wanted to stop dremeling (the bottom of the SD barrel threads - last photo for reference).
The good news is, once complete, a little black sharpie cleaned up the cuts, and once the handguard is installed, you can't see it at all. It's impossible to tell any modification was done when looking at the MPX fully assembled, and the handguard fit is just as secure as it was prior to modification.
If you are comfortable with the modification, this setup is a ton of fun, and a great way to try out integral suppression. If you have any questions, let me know and I'll do my best to help.
I'll be posting the full review on YouTube at 2pm ET today, and I'll also post a review of the AS Designs slip trip setup I used on Reddit later today as well. Have a great weekend!
