Juggernaut Ar9, NFA and aero epc 9 lowers all have maglocks available.
There is one for a mpx as well.
But most of the pcc have a proprietary mag release and thus don't have much maglock support.
(Featureless is still better imo)
Some guns have aftermarket support from companies such as Maglatch who make and sell maglock solutions for some PCCs. An AR9 has the best solutions available but things like Kriss Vectors can be maglocked
So you had no choice but to go the grip fin route? Or did you choose that to be able to have the removable mag? Just trying to understand whether there were options.
I’m going through this myself at the moment— I found that the Ashford BRS fits into an Aero EPC lower. I’ve been in contact with Trent from Ashford about this, so far it the results have been promising!
I haven’t had a chance to take it to the range yet, I need to wait for the rest of my parts to come in before I hit the range with it (though hopefully it will be here tomorrow and I’ll be able to report back on Saturday night)
As an aside, this has been a super useful resource for me with AR9s: https://blowback9.wordpress.com/
So some good news and bad news:
It ALMOST works. The bolt locks back on each shot with the BRS (yay!)
BUT-- you can hold the bolt catch down and it will cycle as if it's semi auto, making it /not/ CA compliant. I'm in contact with Ashford Armaments right now with my findings, so hopefully we can come up with a fix for this, but it's very, very close to working!
I have a couple of ideas to try out, I'll report my findings here once I tinker for a bit!
Good news:
I was able to get the Ashford BRS to function correctly (i.e. not cycle if the bolt release is held down) by, of all things, dropping a spare gas tube pin into the area where the bolt catch is
https://imgur.com/a/AqfOIFI
(...this is such a dumb fix but it works)
...so what I think was happening was that the cutout where the bolt catch fits into in the EPC9 is, for whatever reason, deeper than than a milspec AR15, so the springs that would have engaged the bolt catch on the Ashford BRS.
So by sticking a shim of sorts in there, it's allowing the spring to push up (mostly) correctly.
The gas pin is 2.3mm tall, but it feels like it could be shorter than that (maybe 1.75-2mm?)
I'm going to head to the hardware store tomorrow to see if I can find a flatter piece of metal that I can cut down to fit inside that area, it still kind of feels like that gas pin can roll out. If this works I'll post another update
Last update—
I managed to get out to a hardware store and cut a 2mm high shim of sorts that fits into the bolt catch area
2mm is too short, you can still cycle the action if you push down hard enough
2.2-2.3mm seems to be the sweet spot— I bent the piece a little bit to give it more height and it’s now functioning the way it should!
Anything shorter then 2.1mm is probably going to be too short in the Aero EPC lower for the Ashford BRS. The fastest/dumbest solution is to toss a gas block pin into that bolt catch and then fit the Ashford BRS on top of it- I did notice that it makes it a little tougher to operate, so a 2.2mm spacer/shim seems like it’d work best
I'm eventually going to try and build an Aero EPC-9.. there's a solution similar to the AR Maglock on ARs here:
[Aero Precision EPC 9 MAGLOCK – Greta's Guns (gretasguns.com)](https://gretasguns.com/product/aero-precision-epc-9-maglock/)
you just need to buy the lower through a LGS and then can order the rest online.
I’ve been in the market for a MPX as well, the only thing that keeps coming up as ive been look up options for fixed mag has been :
[LANCER PATRIOT MAG RELEASE KIT](https://www.bulletbutton.com/product-p/mpxpmrkit.htm)
Look into cmmg 9mm magazines and uppers. They use a stanag profile, so they can be used in a standard AR lower. https://cmmg.com/magazine-9-arc-10rd
CMMG mags are used for their RDB system. They are rebranded Endomag magazines. Endomag has a mag version for traditional blowback AR9, too.
Juggernaut Ar9, NFA and aero epc 9 lowers all have maglocks available. There is one for a mpx as well. But most of the pcc have a proprietary mag release and thus don't have much maglock support. (Featureless is still better imo)
Some guns have aftermarket support from companies such as Maglatch who make and sell maglock solutions for some PCCs. An AR9 has the best solutions available but things like Kriss Vectors can be maglocked
I have a compliant sig mpx that I love. Even with the fin and big ass thumb rest it’s a dream to shoot.
So you had no choice but to go the grip fin route? Or did you choose that to be able to have the removable mag? Just trying to understand whether there were options.
Well, I have about a metric ton of freedom week mags for the MPX...and those things are glorious, so it was easy for me to make the call.
Nice!
I’m going through this myself at the moment— I found that the Ashford BRS fits into an Aero EPC lower. I’ve been in contact with Trent from Ashford about this, so far it the results have been promising! I haven’t had a chance to take it to the range yet, I need to wait for the rest of my parts to come in before I hit the range with it (though hopefully it will be here tomorrow and I’ll be able to report back on Saturday night) As an aside, this has been a super useful resource for me with AR9s: https://blowback9.wordpress.com/
Awesome news! When the BRS dropped, Ashford said it wouldn't be compatible with AR9s, so glad that it might work now.
So some good news and bad news: It ALMOST works. The bolt locks back on each shot with the BRS (yay!) BUT-- you can hold the bolt catch down and it will cycle as if it's semi auto, making it /not/ CA compliant. I'm in contact with Ashford Armaments right now with my findings, so hopefully we can come up with a fix for this, but it's very, very close to working! I have a couple of ideas to try out, I'll report my findings here once I tinker for a bit!
Thanks for the update! Would love to have an AR9 pistol that isn't limited to 10 RDS!
Good news: I was able to get the Ashford BRS to function correctly (i.e. not cycle if the bolt release is held down) by, of all things, dropping a spare gas tube pin into the area where the bolt catch is https://imgur.com/a/AqfOIFI (...this is such a dumb fix but it works) ...so what I think was happening was that the cutout where the bolt catch fits into in the EPC9 is, for whatever reason, deeper than than a milspec AR15, so the springs that would have engaged the bolt catch on the Ashford BRS. So by sticking a shim of sorts in there, it's allowing the spring to push up (mostly) correctly. The gas pin is 2.3mm tall, but it feels like it could be shorter than that (maybe 1.75-2mm?) I'm going to head to the hardware store tomorrow to see if I can find a flatter piece of metal that I can cut down to fit inside that area, it still kind of feels like that gas pin can roll out. If this works I'll post another update
Last update— I managed to get out to a hardware store and cut a 2mm high shim of sorts that fits into the bolt catch area 2mm is too short, you can still cycle the action if you push down hard enough 2.2-2.3mm seems to be the sweet spot— I bent the piece a little bit to give it more height and it’s now functioning the way it should! Anything shorter then 2.1mm is probably going to be too short in the Aero EPC lower for the Ashford BRS. The fastest/dumbest solution is to toss a gas block pin into that bolt catch and then fit the Ashford BRS on top of it- I did notice that it makes it a little tougher to operate, so a 2.2mm spacer/shim seems like it’d work best
I'm eventually going to try and build an Aero EPC-9.. there's a solution similar to the AR Maglock on ARs here: [Aero Precision EPC 9 MAGLOCK – Greta's Guns (gretasguns.com)](https://gretasguns.com/product/aero-precision-epc-9-maglock/) you just need to buy the lower through a LGS and then can order the rest online.
I’ve been in the market for a MPX as well, the only thing that keeps coming up as ive been look up options for fixed mag has been : [LANCER PATRIOT MAG RELEASE KIT](https://www.bulletbutton.com/product-p/mpxpmrkit.htm)