AR Sponsor
Posted: 8/26/2025 9:22:59 AM EDT
|
So, my brother is gifting me some 9mm AR parts, lower buffer tube etc. Have we absolutely determined the whole SBR debate? I want to make a truck gun as short as possible complete with a collapsable stock. I need upper recommendations, appropriate buffer weight, etc. |
|
I have never understood the fascination, or hype, for short barreled 9mm ARs. I do not want to run afoul of either State, or Federal, laws. So, I just made mine with a 16” bbl. I can’t have a folding/collapsing stock in my State. So, mine is fixed at about 34”. My weights about 13.7oz, and my buffer is about 8.3oz. It runs well the combined weight of 22oz. I have tried a much heavier buffer, advertised as 11oz, and it did run. Ejection was very weak, and I was using reloads in the +P range. I’ve seen recommendations of 21.5-24oz. So, I think I’ll stay with 22oz. Going lighter may cause battering, increased wear, and velocity loss. I may test it with a slightly higher buffer weight just to see what happens. https://imgur.com/a/OwXj4RS |
|
Originally Posted By gtsteve03: Register it as an SBR if you want a stock. Otherwise, pistol brace if legal in your unlisted state. I live in Michigan. And as far as registering it as an SBR, are they still charging a fee for that? That's one of the things I came here to find out, because I'm still unsure how the ruling went. |
|
Originally Posted By doom1430: I live in Michigan. And as far as registering it as an SBR, are they still charging a fee for that? That's one of the things I came here to find out, because I'm still unsure how the ruling went. Jan 1 2026. You still have to register, but $0 tax stamp. |
"Life is Hard, its Harder if You're Stupid" - John Wayne
|
Part received. Looks like it's only a 9mm Spike's lower. No trigger, but otherwise looks complete, a buffer spring, and a what looks like a lower parts kit which will be used as spare parts since the lower is only missing the trigger. Is the buffer/spring the same as a regular 5.56 buffer/spring? It looks the same as my other buffer/spring. What is the recommended buffer to use in conjunction with a PSA 10.5 upper. This is what I had originally wanted for a truck gun. I will be using a SB3 brace since I don't want to register it yet. I have yet to decide on the trigger and I don't know if it matters or is caliber specific. I may be possibly looking at a binary trigger. There will be no iron sights, and I will be running a PA red dot. |
|
Spring can be the same. Buffer needs to be a 9mm type, which is both heavier and slightly longer than a carbine buffer. Usually they won't rattle when shaken, unlike a carbine buffer. For the trigger, 9mm builds are more specific on what you can use. I'd recommend just starting with an enhanced milspec like an EPT or PNT and seeing if you need to go from there. |
|
Originally Posted By doom1430: Part received. Looks like it's only a 9mm Spike's lower. No trigger, but otherwise looks complete, a buffer spring, and a what looks like a lower parts kit which will be used as spare parts since the lower is only missing the trigger. Is the buffer/spring the same as a regular 5.56 buffer/spring? It looks the same as my other buffer/spring. What is the recommended buffer to use in conjunction with a PSA 10.5 upper. This is what I had originally wanted for a truck gun. I will be using a SB3 brace since I don't want to register it yet. I have yet to decide on the trigger and I don't know if it matters or is caliber specific. I may be possibly looking at a binary trigger. There will be no iron sights, and I will be running a PA red dot. OP.......go read this thread. https://www.ar15.com/forums/ar-15/What-is-newest-hotness-in-bufferless-AR9s/15-788350/ Go get a bufferless upper like the roller delayed 5" barrel Matador upper. Put a railed plug in the buffer hole. Attach an AT3 Tactical folding brace onto the railed plug. This will be the shortest option using your lower. You'll be able to shoot when folded, and roller delayed blow-back is better than straight blow-back. And I'm sure in a few months, there will be a FRT kit or SS kit that will work in the Matador arms upper. Binary triggers don't work in the matador upper anyway. And they suck for what they cost. Also....you need to tell us if this is a Glock mag or Colt mag spikes lower. . |
|
Originally Posted By IdahoPCCinc: OP.......go read this thread. https://www.ar15.com/forums/ar-15/What-is-newest-hotness-in-bufferless-AR9s/15-788350/ Go get a bufferless upper like the roller delayed 5" barrel Matador upper. Put a railed plug in the buffer hole. Attach an AT3 Tactical folding brace onto the railed plug. This will be the shortest option using your lower. You'll be able to shoot when folded, and roller delayed blow-back is better than straight blow-back. And I'm sure in a few months, there will be a FRT kit or SS kit that will work in the Matador arms upper. Binary triggers don't work in the matador upper anyway. And they suck for what they cost. Also....you need to tell us if this is a Glock mag or Colt mag spikes lower. . Originally Posted By IdahoPCCinc: Originally Posted By doom1430: Part received. Looks like it's only a 9mm Spike's lower. No trigger, but otherwise looks complete, a buffer spring, and a what looks like a lower parts kit which will be used as spare parts since the lower is only missing the trigger. Is the buffer/spring the same as a regular 5.56 buffer/spring? It looks the same as my other buffer/spring. What is the recommended buffer to use in conjunction with a PSA 10.5 upper. This is what I had originally wanted for a truck gun. I will be using a SB3 brace since I don't want to register it yet. I have yet to decide on the trigger and I don't know if it matters or is caliber specific. I may be possibly looking at a binary trigger. There will be no iron sights, and I will be running a PA red dot. OP.......go read this thread. https://www.ar15.com/forums/ar-15/What-is-newest-hotness-in-bufferless-AR9s/15-788350/ Go get a bufferless upper like the roller delayed 5" barrel Matador upper. Put a railed plug in the buffer hole. Attach an AT3 Tactical folding brace onto the railed plug. This will be the shortest option using your lower. You'll be able to shoot when folded, and roller delayed blow-back is better than straight blow-back. And I'm sure in a few months, there will be a FRT kit or SS kit that will work in the Matador arms upper. Binary triggers don't work in the matador upper anyway. And they suck for what they cost. Also....you need to tell us if this is a Glock mag or Colt mag spikes lower. . It's a Glock mag lower. I don't know if I want to get that involved with going bufferless. I understand you wanting to help and I appreciate it. I'm really just wanting to do this on the cheap or as cheap as possible and still be reliable. That's why I had planned on going with a PSA 10.5 upper if it's compatible with the Spike's lower. I just need the proper combination of parts - buffer, trigger, etc to make it work every time I pull the trigger. It will never be run in competition or at distance. I just want something that I will be comfortable with taking on the road |
|
Foxtrot Mike Mike 9 upper Tacfire 10" upper PSA Gen 4 10.5" upper These are three contenders and I would appreciate an honest assessment and any possible recommendations. Host lower is a dedicated Spike's Glock mag lower |
|
Originally Posted By doom1430: Foxtrot Mike Mike 9 upper Tacfire 10" upper PSA Gen 4 10.5" upper These are three contenders and I would appreciate an honest assessment and any possible recommendations. Host lower is a dedicated Spike's Glock mag lower Ditch the tacfire as they are low end, with some of their components made in China, and no real exposure in the PCC market. The only decision here is yours.... If you want forward side charging, get the FTM. Good reputation, long time 9mm PCC manufacturer. If you want the rear charging, get the PSA. Good reputation, long time 9mm PCC manufacturer. . |
| I've ordered a parts kit from PSA but I really don't plan on using the trigger that comes with it. Does anyone know if the CMC cassette trigger works in the AR9 platform? And on the outside chance does anyone know if the Spike's AR9 lower a small pin or large pin ? |
|
Originally Posted By doom1430: I've ordered a parts kit from PSA but I really don't plan on using the trigger that comes with it. Does anyone know if the CMC cassette trigger works in the AR9 platform? And on the outside chance does anyone know if the Spike's AR9 lower a small pin or large pin ? Small pin. |
Esstac’s Retarded Social Media Influencer
|
Originally Posted By doom1430: Does anyone know if the CMC cassette trigger works in the AR9 platform? And on the outside chance does anyone know if the Spike's AR9 lower a small pin or large pin ? Drop in trigger should be good to go, as I have AIM in my AERO, son has Timney in his SPIKES **make sure hammer height / profile look like M16 at top of hammer Spikes carry on in std fashion, small receiver pins to hold upper in place Bolt and buffer, figure 20 - 24oz, I be 16oz on bolt, rifle stock with 7oz A2 buffer for almost 25yr off UZI mag Built an AERO, bolt 15oz, buffer 8oz, std carbine stock assembly (tube & spring),, 11" barrel, fed off Glock mags |
Get a regulator or something similar! PSA AR-V with Arizona Regulator |
|
Originally Posted By jaqufrost: Get a regulator or something similar!  https://www.youtube.com/watch?v=3ljqk-dZ2xIThat looks like it could get quite expensive 
|
|
Originally Posted By SBR7_11: Drop in trigger should be good to go, as I have AIM in my AERO, son has Timney in his SPIKES **make sure hammer height / profile look like M16 at top of hammer Spikes carry on in std fashion, small receiver pins to hold upper in place Bolt and buffer, figure 20 - 24oz, I be 16oz on bolt, rifle stock with 7oz A2 buffer for almost 25yr off UZI mag Built an AERO, bolt 15oz, buffer 8oz, std carbine stock assembly (tube & spring),, 11" barrel, fed off Glock mags Thanks for the info  |
|
Originally Posted By doom1430: That looks like it could get quite expensive  Atrius Development Selector 60rd mags go quick! |
|
If ya'll ain't liking this one, which one do you recommend? Nothing that simulates automatic fire. I can't afford that lol |
Member
Joined:
Aug 2025
Posts:
25
EE: 0% (0)
TX, USA
|
Originally Posted By doom1430: If ya'll ain't liking this one, which one do you recommend? Nothing that simulates automatic fire. I can't afford that lol I do have a Rise incoming - will be my first. It is coming bundled at a price perfect to try it out. Never used one though. I do like CMC. Big performance; small price; born in Texas It's the only AR trigger I have more than one of 'cept milspec. |
AR Sponsor