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Originally Posted By alpha0815: What's the consensus on 16" mid-length 5.56 and FRT-15L3? Undecided on barrel just yet but I can open up port if need be. Any benefit to A5 system or is it best to stick with carbine and just try the assortment of buffer weights? Mid length should function just fine. The buffer weights are generally to prevent bolt bounce, to make sure the bolt is all the way forward when the hammer strikes the firing pin. |
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I've made a 22 work with both Super Safety and Rare Breed FRT. The FRT was the second one I got running. I'll talk that one first. I have a Bore Buddy 12" upper, with their weight kit and FRT trip, and both steel and aluminum weight kits. I used the Stainless Steel weight body with two sets of steel weights. I set the trip as far forward as it would go. It now runs on both CCI Mini Mags and 45 grain Suppressor CCIs. I occasionally experience a stoppage in which I fire the first round, and then it's a dead trigger on the second round in the chamber. I clear the malfunction, and then it rips the next 24 in the magazine insanely fast. I'm not even sure what RPM I'm hitting, but it has to be well over 1000. I used ssgtcarroll's milled selector, which is vastly superior to the Rare Breed selector.  " /> " /> " /> " /> " /> " /> " /> " /> " />
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Originally Posted By ELittlefield: I've made a 22 work with both Super Safety and Rare Breed FRT. The FRT was the second one I got running. I'll talk that one first. I have a Bore Buddy 12" upper, with their weight kit and FRT trip, and both steel and aluminum weight kits. I used the Stainless Steel weight body with two sets of steel weights. I set the trip as far forward as it would go. It now runs on both CCI Mini Mags and 45 grain Suppressor CCIs. I occasionally experience a stoppage in which I fire the first round, and then it's a dead trigger on the second round in the chamber. I clear the malfunction, and then it rips the next 24 in the magazine insanely fast. I'm not even sure what RPM I'm hitting, but it has to be well over 1000. I used ssgtcarroll's milled selector, which is vastly superior to the Rare Breed selector. https://i.imgur.com/vrRXeAE.jpeg" target="_blank">https://i.imgur.com/vrRXeAE.jpeg https://i.imgur.com/gtu23lC.jpeg" target="_blank">https://i.imgur.com/gtu23lC.jpeg https://i.imgur.com/3VMOoWo.jpeg" target="_blank">https://i.imgur.com/3VMOoWo.jpeg https://i.imgur.com/DcrkdMs.jpeg" target="_blank">https://i.imgur.com/DcrkdMs.jpeg https://i.imgur.com/sPFkSFk.jpeg" target="_blank">https://i.imgur.com/sPFkSFk.jpeg https://i.imgur.com/VeH5tvR.jpeg" target="_blank">https://i.imgur.com/VeH5tvR.jpeg https://i.imgur.com/61iqG3H.jpeg" target="_blank">https://i.imgur.com/61iqG3H.jpeg https://i.imgur.com/1fuKVgB.jpeg" target="_blank">https://i.imgur.com/1fuKVgB.jpeg https://i.imgur.com/vjQr5H7.jpeg" target="_blank">https://i.imgur.com/vjQr5H7.jpeg Nice! Glad you like it. Changed my user name. A friend of mine who shoots a .22 upper on a registered M16 used a buffer plug. Said it made all the difference. Anyone try one? https://borebuddy.com/product/22lr-plug/ |
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Here are my experiences with two 5.56 lower builds. I wrote them up and then found this thread. So, I will simply summarize them here. Some cautions: - Make sure your BCG has good rings, a good extractor spring/extractor, and ejector spring/ejector. Initially, I got jams with the 14.5" mid gas with a cheap BCG (cheap upper bought during Obama panic) due to a weak extractor spring. Worked fine on semi-auto but not when the ROF increased, third position. Starting with a QUALITY BCG or upgraded BCG is highly recommended. I recommend a Sprinco 5 coil extractor spring or Colt copper colored spring. The Sprinco stuff is way easier to source. - Make sure the gas system is perfect too. Gas block must be properly installed and tight. If you are getting a stutter (changing rates of fire) there is probably a problem in your BCG and/or gas system. - The Griffin ambi lower is excellent but NOT with a RB FRT-15L3. The anti-walk pins with screws interfere with the ambi mechanisms. Other stuff: - I ended up with both FRT lowers being Aero M4E1 because I have some of those in my safe. I predominantly use Geissele Ultra or Super Duty lower parts kits (they go on sale from time to time) because the quality is unmatched by other LPKs. - I built the first lower with an VLTOR A5 buffer system, Green Sprinco spring, and an A5H2 buffer. This resulted in slower bolt speed and a nice pile of brass at 4-4:30 with a mid-length 14.5" upper. I prefer my brass at 3 o'clock, but I expect a suppressed upper will increase the bolt speed. To be tested. - The second one I built initially with a Geissele carbine tube, and Geissele Super 42 with H3. Tested with a 12.5" HODGE small gas port barreled upper, new BCM BCG and Griffin GP5 pinned and welded can. This had hard recoil. To mitigate this I tried a Geissele H2, but was not satisfied. Ended up on a Sprinco Blue and H2 carbine buffer. Then it ran like a scaled dog with brass neatly piled at 3 o'clock. I was surprised that I had to reduce the buffer weight to smooth out recoil, usually I've found that increased weight kept the rifle from cycling too hard. I learn something new every day, but plan to test this lower on other uppers. - I've only had time to test these two lowers on these two uppers, I expect to test several others in the future; short and long barrel, suppressed and un-suppressed. - I have a third trigger that I may install in a SIG MCX LT. I have an 11.5" 5.56 LT and a Rattler LT in 300BLK. I guess it requires an addition part. But I will eventually test. - I have high, medium, and low back pressure cans. I'll see how that affects the performance eventually. |
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Originally Posted By MikeWhiskey: Another thing I noticed is that the detent itself was definitely showing signs of wear and you can see tiny metal shavings on the mat around the tip of the detent, which is showing silver from the damage while the rest of it is more brass colored. (sorry that the picture is slightly out of focus.) Detents always wear. Not an issue as long as they work. They are made to mold to the selector. |
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Originally Posted By MikeWhiskey: It's a cassette style trigger that comes with it's own set of pins/Torx screws: https://rarebreedtriggers.com/wp-content/uploads/2025/05/TR-89465-4-200x200.jpg Admittedly they're sloppy, and on every install I've done there's slight side to side play that would be alleviated by the addition of anti-walk pins (like KNS, which I've used previously and like) and is another modification/upgrade (like @ssgtcarroll's safety/selector) that I think is mandatory for serious (as opposed to "range toy") use. Great question, thanks for asking! These FRTs cannot be considered duty grade "bet you life on them" mechanisms. They were not designed that way, they are simply a work around. It will be a while before we know the weaknesses. I put my own loctite on the anti-walk pins, so far so good. Again I see no reason to change the pins. As I mentioned in my post above there are clearance issues with the ambi mechanism on the excellent Griffin ambi lower which probably would include clearance problems on the the ADM ambi lower which is similar. And I don't think the FRT 15L3 pins will work at all with a Radian ADACS, just looking at it. But I'm not going to try to FRT one of those anyway. I think the FRT will work with the AERO Pro Ambi Lower. But they are not universal. The pins have to be slightly loose to accommodate potential differences in tolerances. The quality of lowers varies a lot. Besides you are not going to get Geissele levels of fit from a company like RB. |
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Originally Posted By MikeWhiskey: I wouldn't say they're going to fall out; the Torx screws on both sides of the threaded trigger pins are larger than the diameter of the hammer/trigger pin holes...but the pins themselves are definitely longer than they need to be which is why there's side to side play. I'm not sure if the how the trigger is fitted into the cassette and if it's interchangeable with anything else for those folks that are concerned with the look/appearance of the trigger itself...and I'm not brave enough to start tearing into a $500 trigger either! I found the janky safety/selector to be a bigger concerned, primarily function but also appearance wise, but @ssgtcarroll has that covered for short money... A solution looking for a problem. Only Aero has those notches you are pointing out. Why don't you call them and ask why they are there. |
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Originally Posted By Gorton87: You can use OEM FCG pins. Put them in a vise up to the center and SLIGHTLY bend them. Will secure them into the trigger pack perfectly. Now THAT is janky. LOL You did that because you are worried about how it looks. Ahha hahahaha! The hilarity just never ends here on ARFCOM. So you will risk pins walking because what, you don't like the screws? I can't wait to tell my friends about this... I have some really harsh comments I could make about your choices and more, but I'm trying not to point out the delusion in a world where everyone is swimming in it. People seem to get really mad when you point out how dumb something is... |
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Originally Posted By deltaheavy: Installed RB/DTT FRT-15L3 in a Sig MPX K with Midnight Machine trip bar. Ran 100% suppressed with form 1 can using factory subsonics from Remington and S&B. Extremely easy to control with short bursts. Only one range trip with ~130 rounds on the system, but no malfunctions yet. Downsides: The MM trip bar requires extensive fitting to work. This has also been indicated by at least two YT reviewers as well. One of the slotted holes was binding on the forward roll pin and the trip bar tail was binding on the underside of the bolt carrier. Luckily I had the tools and patience to correct these shortcomings but YMMV. There are other trip bar mfg’s out there with other users reporting better results. The MM trip bar should be considered a “kit” and not a finished product IMHO. It’s anything but drop in, at least for some. Like OP, I found the factory ambi safety to be sloppy and not confidence inspiring. It worked but I’ll be looking for a replacement eventually. There is a company that makes a much better trip bar that just works. I'm sorry that I've forgotten the name right now. If you look around you will find it, they are mentioned in videos from time to time. |
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Originally Posted By MikeWhiskey: One thing I’m curious about hearing from others is whether or not they experienced an increase in the rate of fire as the magazine emptied…? All of my most recent FA experience has been with burst mechanisms, and belt feds are a different animal. While I was doing my most recent test fire I asked the gentleman with me what he thought and in the interest of starting with a clean slate, loaded a 28-round magazine to do a complete mag dump and sure enough as the magazine emptied the ROF increased without question. I’m not sure that would be any different in an AR with a DIAS and I’m not looking to accelerate any parts breakage either, just something I noticed…🧐 I’m also experienced some bolt bounce in my 5.56 AR that has an H2 buffer and was curious about buffer options besides an H3, I’ve seen some folks using other than those 2 options to get a handle on bolt speed/bounce. Hard to say without thinking about it more, but it'd absolutely caused by a rise in temperature in the system somewhere. Expansion of something increasing gas pressure, or reducing friction. I'd have to think about that for awhile. I've seen it in melt down videos too. |
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Originally Posted By Gorton87: I’ve noticed a slow down as they get hot. Also wondering if you are pulling harder on the trigger. Increased friction somewhere. But likely gas pressure escaping from expansion in tolerances slowing the operation... But an increase of speed that happens sometimes is the more interesting effect. |
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Originally Posted By MikeWhiskey: That is excellent and comprehensive information, thanks @Jambalaya, it's very much useful and appreciated. I said it before and I'll say it again as witnessed by this response; the RBTs definitely work with PCCs, they just require a lot more trial and error than the 5.56/.300 Blackouts do. In their defense, RBT only recommends their FRT for 5.56/.300 Blackout even though it works in other applications; it's just not as straight a line. A lot of folks are NOT interested in doing what it takes to make it work which is why I appreciate y'all making the effort and posting the results. /media/mediaFiles/sharedAlbum/toast_gif-994.gif This is what I'd like to build...  The ATF Is Pissed. The MP5 Now Has A Forced Reset Trigger. |
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Originally Posted By ScottsBad: Now THAT is janky. LOL You did that because you are worried about how it looks. Ahha hahahaha! The hilarity just never ends here on ARFCOM. So you will risk pins walking because what, you don't like the screws? I can't wait to tell my friends about this... I have some really harsh comments I could make about your choices and more, but I'm trying not to point out the delusion in a world where everyone is swimming in it. People seem to get really mad when you point out how dumb something is... There is entire forum groups on this very website dedicated to how something looks. To each their own. What I find delusional is how ignorant members can be to other members over trivial things, in a technical forum of all places. |
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Originally Posted By ScottsBad: Now THAT is janky. LOL You did that because you are worried about how it looks. Ahha hahahaha! The hilarity just never ends here on ARFCOM. So you will risk pins walking because what, you don't like the screws? I can't wait to tell my friends about this... I have some really harsh comments I could make about your choices and more, but I'm trying not to point out the delusion in a world where everyone is swimming in it. People seem to get really mad when you point out how dumb something is... Originally Posted By ScottsBad: Originally Posted By Gorton87: You can use OEM FCG pins. Put them in a vise up to the center and SLIGHTLY bend them. Will secure them into the trigger pack perfectly. Now THAT is janky. LOL You did that because you are worried about how it looks. Ahha hahahaha! The hilarity just never ends here on ARFCOM. So you will risk pins walking because what, you don't like the screws? I can't wait to tell my friends about this... I have some really harsh comments I could make about your choices and more, but I'm trying not to point out the delusion in a world where everyone is swimming in it. People seem to get really mad when you point out how dumb something is... Dude, stay classy. This isn't GD. It's okay to want our guns to look a certain way. |
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Originally Posted By ELittlefield: Dude, stay classy. This isn't GD. It's okay to want our guns to look a certain way. LOL, sorry you are offended. No, sorry but that kind of thing is bad to teach to AR15 noobs. It has to be called out, and I don't see a way to make an impression on this crowd if it doesn't include some criticism. I saw another post seeming to praise the idea. Somebody has to be realistic and point out how really bad, and yes, stupid, this idea is otherwise some people will think it is a legit way to operate. Having your gun look a certain way is one thing, but suggesting that bending FC pins is a good solution is, I don't have any other way to put it, ignorant. Again, sorry, but no there are ideas that are bad no matter how cool you think it makes your rifle and are just plain too dumb to entertain let alone stand mute when they arise. I have been building ARs and the like for about for about 25 years. These are firearms not toys, The Idea of judging, analyzing, and criticizing bad ideas is not fashionable, but so what, it is necessary to keep people tethered to earth. The guy who did that might be some kind of genius, but his idea and solution are sub average. |
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Originally Posted By ScottsBad: LOL, sorry you are offended. No, sorry but that kind of thing is bad to teach to AR15 noobs. It has to be called out, and I don't see a way to make an impression on this crowd if it doesn't include some criticism. I saw another post seeming to praise the idea. Somebody has to be realistic and point out how really bad, and yes, stupid, this idea is otherwise some people will think it is a legit way to operate. Having your gun look a certain way is one thing, but suggesting that bending FC pins is a good solution is, I don't have any other way to put it, ignorant. Again, sorry, but no there are ideas that are bad no matter how cool you think it makes your rifle and are just plain too dumb to entertain let alone stand mute when they arise. I have been building ARs and the like for about for about 25 years. These are firearms not toys, The Idea of judging, analyzing, and criticizing bad ideas is not fashionable, but so what, it is necessary to keep people tethered to earth. The guy who did that might be some kind of genius, but his idea and solution are sub average. Want to give us all a technical reason why it’s ill advised? As an Engineer and a Machinist I honest to god would love to hear your side of the argument in a legible and intelligent manner. Are we concerned about the integrity of the pin? Increasing tensile brittleness? Maybe additional wear to a receivers pin holes? The hammer and trigger do not rotate directly on the pin, but could have seen that as a concern. Please I am genuinely interested as long as you do not revert to turning it into one big opinionated joke. Come to the table and we can be civil about it. If you can’t maybe you should take it to General Discussion. What is funny to me is when I was trying to figure out an over designed solution to the problem a good friend of mine and mentor said “why not put a slight bend, a couple thousands deflection, in the pin?” At the time I felt stupid for trying to over think the problem. This man worked for AAI in the late 60s and assisted with M203 manufacturing and the SPIW program. Later going on to do even greater things. He is one of the most humble, kind, and intelligent people I have ever met. If you are somehow suggesting this man is an idiot for making the suggestion we will just need to agree to disagree and you can go have a laugh with your friends. |
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Originally Posted By ScottsBad: LOL, sorry you are offended. No, sorry but that kind of thing is bad to teach to AR15 noobs. It has to be called out, and I don't see a way to make an impression on this crowd if it doesn't include some criticism. I saw another post seeming to praise the idea. Somebody has to be realistic and point out how really bad, and yes, stupid, this idea is otherwise some people will think it is a legit way to operate. Having your gun look a certain way is one thing, but suggesting that bending FC pins is a good solution is, I don't have any other way to put it, ignorant. Again, sorry, but no there are ideas that are bad no matter how cool you think it makes your rifle and are just plain too dumb to entertain let alone stand mute when they arise. I have been building ARs and the like for about for about 25 years. These are firearms not toys, The Idea of judging, analyzing, and criticizing bad ideas is not fashionable, but so what, it is necessary to keep people tethered to earth. The guy who did that might be some kind of genius, but his idea and solution are sub average. Can you explain what precisely makes it a bad idea? I don’t have your 25 years of experience, so maybe you can illuminate the issue for me. What happened to the trigger pins that you’ve seen lightly bent and used with a cassette trigger? I’m far from offended. Personal attacks are not useful, and not permitted in tech forums. If you have some factual argument to make, please do. |
| The guy makes a multi post diatribe after installing two FRTs in AR15s and doing a little bit of shooting. Then he proceeds to lecture a bunch of people who have installed far more FRTs of various types on many different platforms and tell us how we're ignorant and doing it wrong. Not a great start.... |
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Originally Posted By ScottsBad: A solution looking for a problem. Only Aero has those notches you are pointing out. Why don't you call them and ask why they are there. I've re-read this and your other posts several times and I'm not sure what notches you're talking about, nor why I should call them (Aero) and ask where they're there...? Also, this is Tech NOT GD and while I saw you did edit/delete some of your posts; we're trying to help each other in this thread, not trash, talk down or otherwise shit talk folks that are genuinely trying to help in one way or the other. There's no problem disagreeing with what they have to say, but doing it like a GD shit post/edge lord isn't helping anyone. |
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Originally Posted By ELittlefield: Dude, stay classy. This isn't GD. It's okay to want our guns to look a certain way. Attached File Originally Posted By peachy: Has anyone tried one with a Surefire Optimized Bolt Carrier? I am curious if they are compatible and whether it slows the ROF. I'm definitely interested and will grab one of those when I have a chance and see if it does...if it doesn't I'll still have a VERY nice BCG to show for it! Originally Posted By TheFaz: The guy makes a multi post diatribe after installing two FRTs in AR15s and doing a little bit of shooting. Then he proceeds to lecture a bunch of people who have installed far more FRTs of various types on many different platforms and tell us how we're ignorant and doing it wrong. Not a great start.... ...and this is why I posted this in Tech and NOT GD. I'm still relatively new myself and this particular topic is of great interest to me, and so far we've gotten a lot of great info from folks that have been kind enough to post their experiences good, bad or indifferent which is absolutely to the collective benefit of anyone interested in this particular type (DTT/RBT) FRT. |
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Originally Posted By Xerith: Has anyone tried to run one in a piston driven system yet? I’m looking to buy one if it will indeed work. Either LMT or LWRC. Other wise I’ll toss the extra FRT in another DI system. It'd be REALLY cool if someone did and gave us the scoop...HINT HINT. For some reason I'm thinking they're not going to work because of the BCG interface with the reset mechanism but that is based on ZERO facts and is, in fact, a shitty ass guess that I wouldn't want anyone to take seriously and get discouraged from doing so! |
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Originally Posted By Xerith: Has anyone tried to run one in a piston driven system yet? I’m looking to buy one if it will indeed work. Either LMT or LWRC. Other wise I’ll toss the extra FRT in another DI system. As long as the bcg can trip the locking bar, I don't see why it wouldn't work |
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Originally Posted By HK94dude: As long as the bcg can trip the locking bar, I don't see why it wouldn't work Originally Posted By HK94dude: Originally Posted By Xerith: Has anyone tried to run one in a piston driven system yet? I’m looking to buy one if it will indeed work. Either LMT or LWRC. Other wise I’ll toss the extra FRT in another DI system. As long as the bcg can trip the locking bar, I don't see why it wouldn't work Agreed, but I don't own one to say for sure. The shape of the bottom of the BCG is what would matter, not the nature of the operating system. |
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Originally Posted By Xerith: Has anyone tried to run one in a piston driven system yet? I’m looking to buy one if it will indeed work. Either LMT or LWRC. Other wise I’ll toss the extra FRT in another DI system. I am running a superlative arms piston conversion kit in my 16in carbine. It works perfectly fine. I can not speak for other brands though. Like mentioned above, as long as the bolt carrier is M16 cut and trips the reset bar, it should run. |
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Cool. I’ll have to look into a piston system then. The reason I was asking is because Micah Mayfield did a video on FRT on different firearms and the PWS did not work. I have a few piston systems, just not on the AR platform. In the mean time I have my second trigger in my DDM4 V7 16”. With a super 42 spring and H2 running an OCL polonium it is crazy over gassed. Been looking at flow throughs last couple of months. Guess now is the time to grab one. The new B&Ts look really good. |
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Originally Posted By Xerith: Cool. I’ll have to look into a piston system then. The reason I was asking is because Micah Mayfield did a video on FRT on different firearms and the PWS did not work. I have a few piston systems, just not on the AR platform. In the mean time I have my second trigger in my DDM4 V7 16”. With a super 42 spring and H2 running an OCL polonium it is crazy over gassed. Been looking at flow throughs last couple of months. Guess now is the time to grab one. The new B&Ts look really good. I remember that video. Knowing absolutely nothing about that gun, my bet it was the shape of the bolt carrier not tripping the forced reset bar causing it not to work, and nothing to do with the piston system. |
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Originally Posted By Jeeps-And-Guns: I remember that video. Knowing absolutely nothing about that gun, my bet it was the shape of the bolt carrier not tripping the forced reset bar causing it not to work, and nothing to do with the piston system. ^ As has been said by other folks, this exactly... It's not the operating system (DI versus piston) that's dictating whether or not FRTs will work in any given platform; it's the interface between the rear of the bolt carrier and the forced reset mechanism on the trigger. My FRT'd CMMG Banshee .45 is RDB and it couldn't run better and has a near UMP-like rate of fire, which I'm accustom to and works well with the recoil impulse... Should fit comments are NOT at all helpful and the reason why I started this thread. $500 is a whole lot of money to tie up in a trigger so when someone has a formula actually figured out, it's valuable to all of us when they post it up. There's definitely been cases where something the "should fit/work" didn't and vice versa. Details are critical in knowing what works which is why I was asking folks to get as much in the weeds as they want to, down to magazine choice and ammo if they want. I hope that doesn't sound like I'm being a jerk...if so I apologize, I just want folks getting solid information and helping each other out saving money and time with what does and doesn't work! |
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Hello i'm new to the site and to frt's. just wanted to see what to expect with my gun a 16in carbine bushmaster non adj gas block. as i haven't shot it yet. I bought and installed an h2 buffer and full profile BCG. it is a Rare Breed trigger btw otherwise stock i have a Saker 556k on it as well. what should i expect? will it run? will it be gassy. Should i run a H3 instead? How fast will it shoot? |
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Originally Posted By frisbie8: Hello i'm new to the site and to frt's. just wanted to see what to expect with my gun a 16in carbine bushmaster non adj gas block. as i haven't shot it yet. I bought and installed an h2 buffer and full profile BCG. it is a Rare Breed trigger btw otherwise stock i have a Saker 556k on it as well. what should i expect? will it run? will it be gassy. Should i run a H3 instead? How fast will it shoot? It’s likely to run with an H2. As for rate of fire, probably high. It won’t be much gassier than shooting semi auto. |
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Can someone with the newer iteration of the Rare Breed branded FRT15L3 please take a caliper measurement for me? When installed and in position 3 with trigger fully depressed (like where it would be during firing if you were white-knuckling the trigger), how high does the highest point of the hammer sit above the top of the lower receiver (where the upper sits)? When the hammer is cocked and selector is in position 3 the hammer will sit a little lower than when the trigger is being pulled in the same situation. I'm specifically looking for an accurate measurement when trigger is being held to the rear. This is to help me evaluate the RB as possibly being a fix for a binding issue on a rimfire belt-fed. I'd prefer not to have to buy one and measure it only to discover it will still bind. Any help would be great. Thank you in advance! To add to this thread, my DTT actually runs decently well with my Lakeside Razorback with FA trip on bolt. There is some binding when it gets hot which is what I'm trying to iron out. I got it running about 95% by removing material from the bottom of the rear takedown pin allowing the rear of the upper to sit slightly higher in the lower (alleviated the binding). This is done in an Aero enhanced lower which allows me to put pressure on the rear takedown lug using the tension screw. Modifying the rear takedown pin makes disassembly a pain in the ass, though. I'm trying to avoid removing material from the hammer if at all possible. |
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Originally Posted By fordkicksass: Can someone with the newer iteration of the Rare Breed branded FRT15L3 please take a caliper measurement for me? When installed and in position 3 with trigger fully depressed (like where it would be during firing if you were white-knuckling the trigger), how high does the highest point of the hammer sit above the top of the lower receiver (where the upper sits)? When the hammer is cocked and selector is in position 3 the hammer will sit a little lower than when the trigger is being pulled in the same situation. I'm specifically looking for an accurate measurement when trigger is being held to the rear. This is to help me evaluate the RB as possibly being a fix for a binding issue on a rimfire belt-fed. I'd prefer not to have to buy one and measure it only to discover it will still bind. Any help would be great. Thank you in advance! To add to this thread, my DTT actually runs decently well with my Lakeside Razorback with FA trip on bolt. There is some binding when it gets hot which is what I'm trying to iron out. I got it running about 95% by removing material from the bottom of the rear takedown pin allowing the rear of the upper to sit slightly higher in the lower (alleviated the binding). This is done in an Aero enhanced lower which allows me to put pressure on the rear takedown lug using the tension screw. Modifying the rear takedown pin makes disassembly a pain in the ass, though. I'm trying to avoid removing material from the hammer if at all possible. I’m gonna need some ms paint to understand your ask. But the good news is I’ll take those shims to work and ship them tomorrow to you. And I wanted to chime in on that cat earlier in the thread and let him know my slightly bent trigger and hammer pins that retain one of my RBs in the suppressed PDX have fired nearly 2 cases of suppressed 556 since that post. Zero issues lol |
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I run the RB in my Spear LT 300 BO which is piston driven and it runs really well with subs. I've not tried it with supers yet but zero issues thus far. I use the Frankenstein Armory trip bar and it's suppressed 100% of the time. I've since added a Mototech gas valve but haven't tested it in FRT mode yet. I only have one FRT-friendly range without renting a private bay. The only thing I hate about the trigger is the trigger feel itself. Absolutely horrendous with a tremendous amount of weighted pre travel before it fires. There's no wall, just lots of travel and then bang. Literally the worst trigger I've ever experienced. You seem to lose a bit of feel with any of them (the AZR took away the clean break of my Geissele) but the RB is by far the worst. Unfortunately, it otherwise works so I may leave it where it is. |
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Originally Posted By jwlaxton: It would be interesting to know if it would work with the firing pin latch on the Spear LT BCG, or whether it would also have to be removed. It comes in from the side vs the top. I've also been curious whether it would work with the Spear LT 7.62x39 which supposedly needs a heavier hammer spring than mil-spec triggers. You remove the firing pin latch. I hated that thing anyway... |
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Originally Posted By Ape_Factory: You remove the firing pin latch. I hated that thing anyway... Actually, I have since answered that question for myself. While Frankenstein Armory says to do that, I left mine in and haven't had any issues. Only the Virtus requires removal, not the Spear LT. |
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Originally Posted By HKH: I’m gonna need some ms paint to understand your ask. But the good news is I’ll take those shims to work and ship them tomorrow to you. And I wanted to chime in on that cat earlier in the thread and let him know my slightly bent trigger and hammer pins that retain one of my RBs in the suppressed PDX have fired nearly 2 cases of suppressed 556 since that post. Zero issues lol @HKH Yep it is hard to put into words so here is a pic with an indication of what I'm looking for. If anyone can help, I'd really appreciate it. The measurement is seek is roughly marked in red. It is the height the highest part of the hammer sticks up above the lower receiver when the FCG is in position 3 and trigger is pulled fully to the rear simulating how far the hammer sticks up into the upper receiver when the trigger is pulled and bolt is moving rearward. ETA: Specifically looking for this measurement from the newer branded Rare Breed FRT-15L3 pack. Attached File |
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Originally Posted By fordkicksass: @HKH Yep it is hard to put into words so here is a pic with an indication of what I'm looking for. If anyone can help, I'd really appreciate it. The measurement is seek is roughly marked in red. It is the height the highest part of the hammer sticks up above the lower receiver when the FCG is in position 3 and trigger is pulled fully to the rear simulating how far the hammer sticks up into the upper receiver when the trigger is pulled and bolt is moving rearward. ETA: Specifically looking for this measurement from the newer branded Rare Breed FRT-15L3 pack. https://www.ar15.com/media/mediaFiles/163138/1000003950_jpg-3658571.JPG Oh that’s easy. Gimme a bit and I’ll post what I think you’re wanting. Correct me if I’m wrong 
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I came up with .293” - see below Hard to take the pic so it’s a story line for you and a final shot for perspective. Getting the position set I believe you were looking for  Measuring  Best I could guesstimate with only two hands  Final shot for perspective -hammer fully compressed compared to the trip bar thing that activates the RB frt. 
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Originally Posted By MikeWhiskey: One thing I’m curious about hearing from others is whether or not they experienced an increase in the rate of fire as the magazine emptied…? All of my most recent FA experience has been with burst mechanisms, and belt feds are a different animal. While I was doing my most recent test fire I asked the gentleman with me what he thought and in the interest of starting with a clean slate, loaded a 28-round magazine to do a complete mag dump and sure enough as the magazine emptied the ROF increased without question. I’m not sure that would be any different in an AR with a DIAS and I’m not looking to accelerate any parts breakage either, just something I noticed…🧐 I’m also experienced some bolt bounce in my 5.56 AR that has an H2 buffer and was curious about buffer options besides an H3, I’ve seen some folks using other than those 2 options to get a handle on bolt speed/bounce. Rate of fire increase caused by the extra magazine spring pressure when the mag is full. The spring pressure tapers off as the magazine gets emptied and the bolt can strip rounds out of the mag easier and the rate of fire increases. Happens on traditional full autos as well. |
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Originally Posted By MyakkaVice: Rate of fire increase caused by the extra magazine spring pressure when the mag is full. The spring pressure tapers off as the magazine gets emptied and the bolt can strip rounds out of the mag easier and the rate of fire increases. Happens on traditional full autos as well. Gotcha, thank you, that makes sense. I have previous F/A experience but was never big on mag dumps either. NOT that I’m big on them now, I’ve just done several with my FRT installs, more as a function test than anything else…🧐 |
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Rare Breed trigger in an Adams Arms piston upper was very smooth- when it ran. My AA upper is a factory built 16.5" COR, which uses a rifle length gas system. Unfortunately, the rifle length gas piston on a 16.5" is marginal on gas, and always has been, even running it on the factory Adams lower. When it gets a little dirty the bolt is not running rearward far enough to pick up another round from the magazine. I need to try it with a H1 buffer instead of H2 next time. Or put a can on it- which is probably the best solution since it's a piston upper anyway. But, for a few magazines it ran well- I'd estimate around 700 RPM. Noticeably slower than the 10.5" with a can, and a 16" DI carbine gas with a can that I also tried. |
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Reporting in that a CMMG 9mm Banshee (RDB) works after bumping to an H3 buffer (specifically a T3 from Spike's). This is the only 9mm I know of that uses a standard buffer (without a spacer), so you don't have unlimited, affordable options above an H2. Choked like a Freshman invited to prom with a normal carbine buffer, but gulps along with the H3. It's a Mk9 lower taking Colt SMG mags like Jesus intended. Have to order this separate from the upper. Side note, CMMG's cerekote sucks ass. Anodize things, you asses. Two test trips to the range and the thing is showing raw aluminum. |
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