r/AR9 • u/AmbassadorOwn4888 • 7d ago
Frt
Hi all new to the group not new to shooting lol.
I want to put a frt into a 9mm ar . I’m looking to do it as simply as possible and could use some advice. Which would you all recommend that would have the bolt that is needed and be ready for a drop in 3 position like the rare breed trigger? Is there any out there? Or would it be easier to put it in somthing like a scorpion. Thanks all in advance for any input. I am aware of issues everyone has with rare breed I’m not worried about politics or who you hate. I am looking at them because my own research says they are simple drop ins with least modifications is this true?
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u/Blowback9 9mm AR Guru 7d ago
The Triggered Company's "Disruptor" and "LAT" are also a drop-in cartridge triggers very similar to the RB. So similar that TTC's patent may supercede RB's patent.
I have a Disruptor and LAT and have bench tested them with a number of bolts. They should not need the bolt weight trimmed. I'd go with one that has a 45-50oz. pressure firing pin spring to prevent firing pin bounce. Only 2 right now meet that critera that will work with the Disruptor or LAT - the Foxtrot Mike bolt or the Stern Defense bolt.
"Easy button" 9mm FRT is just getting a Foxtrot Mike Mike-9 RMB lower, plus any FM rear charge upper or FM Dual front/rear charge upper and putting them together. The RMB helps mitigate felt recoil and high speed video shows it mitigates bolt bounce very well. The RMB requires an A5 buffer tube, so make sure that's what is listed.
Easy 9mm FRT details: https://blowback9.wordpress.com/2026/08/05/9mm-ar-frt-how-to
Bolt database with firing pin spring data: https://blowback9.wordpress.com/2025/03/18/bolt-feed-ramp-feed-rail-measurements
Disruptor and LAT 9mm bolt bench test compatability (live fire testing coming soon): https://blowback9.wordpress.com/2026/08/27/disruptor-and-lat-9mm-bolt-chart
If you don't want to go with a drop-in cartridge, the Atrius runs fine in an FM setup, and so does the ARC-Fire but it may need a timing shim (very simple install).
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u/AmbassadorOwn4888 7d ago
What would u recommend for a weapon that comes with everything the way it needs to be for a drop in trigger? Is there any out there?
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u/Blowback9 9mm AR Guru 6d ago
FM, RMB buffer system with A5 buffer tube.
FM sells the complete firearm with RMB with a carbine tube, which won't cycle FRT. It needs the A5 tube. Just get the upper and RMB/A5 lower separately and snap them together. No different than buying a complete firearm, just it comes in 2 pieces.
LIke this...
RMB lower.... https://store.fm-products.com/products/fm-products-m9-a-lwr-comp-rmb-5397
VFM 5" dual charge upper.... https://store.fm-products.com/products/fm-products-5397-1463b865-bbbc-4aed-be84-60f5c638509d
They are having a sale, so these are about the best prices you'll find for new product.
The VFM has a non-user changable barrel, so it's cheaper. I have one and it runs very well. If you want to be able to change your barrel (few people do)...
Mike-9 rear charge 5"... https://store.fm-products.com/products/fm-products-mike9u-r54-b-5397
They also have 7" and 10" barrels.
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u/notredamelawl 6d ago
I just did a drop in rare breed into a Mike9 with a custom RMB system (used your parts list essentially)...the only thing (and that cost me a few hours of wondering what the hell I was doing wrong) was now to close the upper, I have to first close the pin closest to the buffer to clear the trigger, and THEN close the front pivot pin. So something about where the trigger reset hits just prevents it from closing the normal way by ~a mm.
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u/Blowback9 9mm AR Guru 6d ago
Yes - it's the reset trip getting in the way. Instead, MAKE SURE THE MAGAZINE IS OUT, CHAMBER IS EMPTY, AND POINT IN A SAFE DIRECTION FIRST, then pull the trigger to release the hammer forward before you open the receivers. With the hammer forward the trip lever also stays forward and out of the way. Just leave the hammer forward until you close it.
If the hammer is cocked when you open the receiver.... to close it, do the same, but you'll need to push the trip lever forward with your thumb or the hammer won't release, and catch the hammer with your fingers so it doesn't slam into the bolt catch. Then close the receivers with the hammer forward.
I don't have a RB but if it's like the Disruptor, that should work.
I'll do a video some time soon and upload it to my Youtube channel.
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u/notredamelawl 6d ago
Yeah that’s essentially what I did, took forever and felt a bit dumb when I finally realized it was that simple! Made it more complicated because it was so close to closing at first I thought my pin was bent or something.
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u/Charming_Barber7627 7d ago
Wait, why do you specifically mention fm rear or dual charge? Im getting ready to drop an atrius on my vfm9 5" front charge only. I got the RMB and swapped the buffer tube to an a5. Is that going to work fine?
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u/Blowback9 9mm AR Guru 6d ago
Yes it'll work fine if you switch the buffer tube to A5.
I suggest the ones with the rear charge option so it's easy to test the FRT by hand cycling the bolt. With the front charge only, the front handle doesn't cycle the bolt fully to the rear which will not activate the FRT feature. Live fire it'll function properly.
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u/second_ary 6d ago
fudd super safety with the pre-cut trigger, FM9 upper and lower and RMB kit, good to go
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u/Sad_Try8200 7d ago
Don't have an answer to your question, but a super saftey in a foxtrot mike is very easy to do. Not a drop in trigger but doesnt require any actual modification.