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Who here is using a FRT with a 22LR. What is your setup? (Page 6 of 11)
| Anyone know why BB quit carrying the Tungsten weight and switched to the much inferior lead? I bought a set of their Tungsten weights a couple of years ago on a 10/22 project and they weren’t terribly expensive then, but all Tungsten products have gone up a lot since then (CAR buffer weights went from $25 for 3 to $50 and more now). OK, cost is likely but is that alone a good enough reason to replace them with lead that mushrooms, gets stuck, and has to be drilled out? Not to me it isn’t. |
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Originally Posted By Big-Bore: Anyone know why BB quit carrying the Tungsten weight and switched to the much inferior lead? I bought a set of their Tungsten weights a couple of years ago on a 10/22 project and they weren’t terribly expensive then, but all Tungsten products have gone up a lot since then (CAR buffer weights went from $25 for 3 to $50 and more now). OK, cost is likely but is that alone a good enough reason to replace them with lead that mushrooms, gets stuck, and has to be drilled out? Not to me it isn’t. Maybe finding a reliable supplier with reasonable/predictable supply costs/times for their desired quantities likely made it tough? I don't imagine they sell a ton of those. That's just a guess, though. |
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Hi, I have a Cornfire MARC and nothing seems to work. The MARC works perfectly in my 5.56 upper (hand cycling and live fire) but refuses to work in my 22 upper. I have a completely unmodified milspec trigger and tested the MARC and saw absolutely no binding. The lower is an Andro. My 22 upper uses a 16” BB Apogee Match barrel, a fully upgraded BB bolt carrier, a deluxe BB weight kit, and other various BB parts like a pressure plug and trip kit. I built it myself using an upper I got off of GAFS. While semi seems to work fine with the 22 upper (tested via live fire and function testing via hand cycling), it absolutely refuses to work in super safe mode. I can confirm that the trip was installed correctly as the lever seems to be moving fine in semi. What I noticed in super safe mode was that the hammer refuses to cock and the bolt won’t move back as far as it should. It closes just fine when I release the charging handle, though. I’m at a loss, as I’ve tried adjusting the trip screw a bunch of times and still can’t figure out what’s going on. |
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Originally Posted By fiftytencee: Hi, I have a Cornfire MARC and nothing seems to work. The MARC works perfectly in my 5.56 upper (hand cycling and live fire) but refuses to work in my 22 upper. I have a completely unmodified milspec trigger and tested the MARC and saw absolutely no binding. The lower is an Andro. My 22 upper uses a 16” BB Apogee Match barrel, a fully upgraded BB bolt carrier, a deluxe BB weight kit, and other various BB parts like a pressure plug and trip kit. I built it myself using an upper I got off of GAFS. While semi seems to work fine with the 22 upper (tested via live fire and function testing via hand cycling), it absolutely refuses to work in super safe mode. I can confirm that the trip was installed correctly as the lever seems to be moving fine in semi. What I noticed in super safe mode was that the hammer refuses to cock and the bolt won’t move back as far as it should. It closes just fine when I release the charging handle, though. I’m at a loss, as I’ve tried adjusting the trip screw a bunch of times and still can’t figure out what’s going on. Have you gotten that upper running in Super Safe with any other types of triggers? |
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Originally Posted By fiftytencee: Hi, I have a Cornfire MARC and nothing seems to work. The MARC works perfectly in my 5.56 upper (hand cycling and live fire) but refuses to work in my 22 upper. I have a completely unmodified milspec trigger and tested the MARC and saw absolutely no binding. The lower is an Andro. My 22 upper uses a 16" BB Apogee Match barrel, a fully upgraded BB bolt carrier, a deluxe BB weight kit, and other various BB parts like a pressure plug and trip kit. I built it myself using an upper I got off of GAFS. While semi seems to work fine with the 22 upper (tested via live fire and function testing via hand cycling), it absolutely refuses to work in super safe mode. I can confirm that the trip was installed correctly as the lever seems to be moving fine in semi. What I noticed in super safe mode was that the hammer refuses to cock and the bolt won't move back as far as it should. It closes just fine when I release the charging handle, though. I'm at a loss, as I've tried adjusting the trip screw a bunch of times and still can't figure out what's going on. Take a look at the auto sear pocket in the upper, do you see any signs of rubbing on the left side? When in FRT mode, the lever is slid to the left, it can hit the edge of the pocket if the pocket is not in spec and a fair amount of uppers have out of spec pockets... might also look at the end of the pocket towards the RE. The lever may not be impacting enough to impede function but you don't want any contact. If you have one or both, open that pocket until the cam lever can move without contacting the auto sear pocket. The only other cause I can think of is the reset screw on the BB trip being to far out. If its as far in as it can go and you still get binding in FRT try another mil spec trigger if you have one. |
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Originally Posted By fiftytencee: Nope, the milspec trigger is the only one I have. Click "quote" under the person's post so that we know who you're replying to. Your symptoms sound like the ones I get when my Bore Buddy is either installed wrong, that is sitting too far forward so the Cornfire lever isn't sitting in the pocket, or when the adjustment screw is too far out. |
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Originally Posted By shultz: The lever is in the trip pocket once the upper is closed correct? Take a look at the auto sear pocket in the upper, do you see any signs of rubbing on the left side? When in FRT mode, the lever is slid to the left, it can hit the edge of the pocket if the pocket is not in spec and a fair amount of uppers have out of spec pockets... might also look at the end of the pocket towards the RE. The lever may not be impacting enough to impede function but you don't want any contact. If you have one or both, open that pocket until the cam lever can move without contacting the auto sear pocket. The only other cause I can think of is the reset screw on the BB trip being to far out. If its as far in as it can go and you still get binding in FRT try another mil spec trigger if you have one. I think that might be the problem. When I looked at both uppers there was a tiny nick in the sear pocket that the 22 upper had that the Andro didn’t have. I’ll provide pics if it helps. Was hoping that I didn’t have to cut anything but it is what is. Edited to include images Andro upper:  " />22 upper:  " /> |
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Originally Posted By ELittlefield: Click "quote" under the person's post so that we know who you're replying to. Your symptoms sound like the ones I get when my Bore Buddy is either installed wrong, that is sitting too far forward so the Cornfire lever isn't sitting in the pocket, or when the adjustment screw is too far out. I’ll check again to see if maybe I installed the trip kit wrong. |
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Originally Posted By fiftytencee: I'll check again to see if maybe I installed the trip kit wrong. That mark is enough that I'd remove some material so the lever clears. It hurts nothing, touch it up with some aluminum black. |
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Originally Posted By shultz: Pull your firing pin when you clean. Not only does it and the channel get dirty, you may have a two piece firing pin spring like I just did  Getting that spring out intact is sometimes its own unique challenge. |
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Originally Posted By lugnutwrench2: Getting that spring out intact is sometimes its own unique challenge. Attached File |
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Originally Posted By shultz: The lever should sit in the pocket between the trip, reset surfaces. That mark is enough that I'd remove some material so the lever clears. It hurts nothing, touch it up with some aluminum black. Can confirm that the lever is inside that little square hole in the trip. I’ll get the upper cut tomorrow. Praying that this works lmao |
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Originally Posted By fiftytencee: Can confirm that the lever is inside that little square hole in the trip. I’ll get the upper cut tomorrow. Praying that this works lmao Keep us posted! Hope it works. |
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I just slung another 1,000+ rds down range today across 13 different types of ammo, and thought I'd share my notes. The actual springs and weights used are specific to my gun, so don't expect to use these as "recipes" that will work in yours. But the relative differences in what I observed may be useful to you. Most of this stuff would cycle reliably in semi with a BB steel weight carrier with all steel weights, so that was my baseline, but I did have some exceptions (see below). I tried to hone on on which recoil spring (3 lb blue, 4 lb yellow, 6 lb red) would work best with which ammo. I only paid attention to ejection orientation with the hottest rounds. For the most part, casings were ejecting around the 3 o'clock position. I was using fully-loaded 25 rd mags. Success criteria were simple: 25 rds of brrrt (no malfunctions for an entire mag, times two where I had enough ammo). Unless otherwise stated, the entries below met those criteria with each indicated spring with the steel carrier and all steel weights. Here's what I found (bold indicates what I found to be the "best" setup):
As my round count increased, the hotter rounds did better w/ the blue (3 lb) spring, which kind of makes sense, since it was getting really gritty (which I'm assuming added more drag to both the recoil and return of the bolt). Almost universally, I needed to ease up on the trigger to get things to run with the blue spring to avoid choking things off, even with hotter rounds. The one exception might have been the AM22 (or maybe that was just in my head). One call-out here is that ammo selection makes a really big difference when first trying to tune a FRT. Some will work with a wide variety of configurations, and some only operate in a much narrower context. CCI Stingers and CCI Velocitors are great to establish a baseline working setup, because they're very forgiving. That said, they're expensive, so I probably won't buy more unless I need to dial in another rifle. The Remington 38 gr Ranch Hand R21273 is a great substitute that is widely available at almost half the price. It probably goes without saying that I won't be purchasing Winchester ammo again. Maybe I just got unlucky and got bad batchs, but life is too short to have to mess with that crap, especially since it's not cheap. I was not impressed with the Aguila. I know it's cheap-ish, but there are similarly-priced options that have been more reliable for me. Even Federal worked better, and I wouldn't describe that as reliable for FRT use. I hope that helps somebody out there. |
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| Are you making sure that the trip is installed correctly? |
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I can see where you're coming from, 'cause I know where you've been and I can see where you're going 'cause I can see the direction you're headed in. I just don't know where the hell you're at right now.
I can see where you're coming from, 'cause I know where you've been and I can see where you're going 'cause I can see the direction you're headed in. I just don't know where the hell you're at right now.
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Originally Posted By fiftytencee: Update: After removing some material from the sear pocket in the upper, I still have the same result as before. Using a 1/8 punch or drill bit, lay it across the lower right above the selector stop and see if the lever will pin it in place like this Attached File My lever will go much further but the above is sufficient even for 22lr as far as I know. Attached File |
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Originally Posted By shultz: The only other place the lever could be binding dosen't make sense as you say it works for 5.56... Using a 1/8 punch or drill bit, lay it across the lower right above the selector stop and see if the lever will pin it in place like this https://www.ar15.com/media/mediaFiles/39247/1000005660_jpg-3689421.JPG My lever will go much further but the above is sufficient even for 22lr as far as I know. https://www.ar15.com/media/mediaFiles/39247/1000005661_jpg-3689423.JPG It clears  " />
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Originally Posted By fiftytencee: It clears <a href="https://i.postimg.cc/w71jP0Dx/IMG-1340.jpg</a>" >[url]https://i.postimg.cc/w71jP0Dx/IMG-1340.jpg">https://i.postimg.cc/w71jP0Dx/IMG-1340.jpg">[url=https://postimg.cc/w71jP0Dx]https://i.postimg.cc/w71jP0Dx/IMG-1340.jpg I'm out of ideas for where the lever is binding... Have you put your 5.56 upper back on to verify it will at least still pass hand function? |
| Post a picture of your bolt carrier (bottom of it), the trip and the weight kit. |
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| Same here. We need pictures to be able to help. |
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I can see where you're coming from, 'cause I know where you've been and I can see where you're going 'cause I can see the direction you're headed in. I just don't know where the hell you're at right now.
I can see where you're coming from, 'cause I know where you've been and I can see where you're going 'cause I can see the direction you're headed in. I just don't know where the hell you're at right now.
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" />
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Originally Posted By fiftytencee: Yep, and it passes function testing easily. Maybe it's the Borebuddy SS trip/ MARC combination that is the issue? I don't know |
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Originally Posted By fiftytencee: <a href="https://i.postimg.cc/QF51LXcK/IMG-1341.jpg</a>" >[url]https://i.postimg.cc/QF51LXcK/IMG-1341.jpg">https://i.postimg.cc/QF51LXcK/IMG-1341.jpg">[url=https://postimg.cc/QF51LXcK]https://i.postimg.cc/QF51LXcK/IMG-1341.jpg |
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Originally Posted By fulautotank: The only thing I can add is that I have a working 22 setup with a SS equipped lower. When I move that upper to a MARC equipped lower I get the same problem as you. Works fine in semi but bolt will not retract fully in frt mode. Adjusting BB SS trip screw in or out did not help. Maybe it's the Borebuddy SS trip/ MARC combination that is the issue? I don't know |
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Originally Posted By fiftytencee: I was able to push it a tiny bit further but not much further. The lever did slide right into the slot in the trip though before pushing it. Find what's preventing the trip from moving all the way to the rear and you should be GTG. Attached File |
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Originally Posted By fulautotank: The only thing I can add is that I have a working 22 setup with a SS equipped lower. When I move that upper to a MARC equipped lower I get the same problem as you. Works fine in semi but bolt will not retract fully in frt mode. Adjusting BB SS trip screw in or out did not help. Maybe it's the Borebuddy SS trip/ MARC combination that is the issue? I don't know Nope, mine runs just about 100%. |
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Originally Posted By shultz: Huh, so the back edge of the trip sled can't meet the front edge of the bolt? If this is the case, you found the problem. That gap would create the same issue as having the reset adjustment screw out to far and will prevent the bolt from coming all the way back... Find what's preventing the trip from moving all the way to the rear and you should be GTG. https://www.ar15.com/media/mediaFiles/39247/1000005662_jpg-3689500.JPG At this point I think I’m grasping for straws, but all signs are pointing towards the lever. It won’t budge at all. I’m considering removing some material from it but idk if that would work. |
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Originally Posted By fiftytencee: At this point I think I’m grasping for straws, but all signs are pointing towards the lever. It won’t budge at all. I’m considering removing some material from it but idk if that would work. How far out is the set screw on the trip? |
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Originally Posted By fiftytencee: At this point I think I'm grasping for straws, but all signs are pointing towards the lever. It won't budge at all. I'm considering removing some material from it but idk if that would work. I wouldn't do that just yet. Call cornfire, Drew will probably answer. I had a timing issue using the MARC with 9mm, the lever was tripping early way before the bolt had even nearly closed. After going over my set up and everything I had done he gave me his blessing to remove material from the end of the trip lever. He even said if I went to far he'd replace the lever! I fixed the timing issue, functions flawlessly. |
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Originally Posted By shultz: I wouldn't do that just yet. Call cornfire, Drew will probably answer. I had a timing issue using the MARC with 9mm, the lever was tripping early way before the bolt had even nearly closed. After going over my set up and everything I had done he gave me his blessing to remove material from the end of the trip lever. He even said if I went to far he'd replace the lever! I fixed the timing issue, functions flawlessly. I’ll try giving them a call tomorrow. I’m going to take a break from this stuff for the night. |
| DON’T remove material from the lever. Instead, take some off your trigger on the top edge of the left side. I had to remove a tiny bit so that my trigger had a little more travel so the hammer could drop. After I removed a little and polished it, it worked better. When I first installed the MARC, a very firm pull of the trigger was required to make it fire. Do NOT remove any material from the right side. Doing so may cause the gun to fire when it is on safe. |
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I can see where you're coming from, 'cause I know where you've been and I can see where you're going 'cause I can see the direction you're headed in. I just don't know where the hell you're at right now.
I can see where you're coming from, 'cause I know where you've been and I can see where you're going 'cause I can see the direction you're headed in. I just don't know where the hell you're at right now.
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Originally Posted By lugnutwrench2: Does the problem go away when screwed all the way back in? We had been messaging before he posted. I believe he said it was doing the same thing with the screw ran in completely. Here’s a picture of my A1 setup with the Cornfire. The screw is about .345 from the top of the screw to the trip. Also note the position of the trip and the lever. It runs practically 100% with good ammo. It’s a blast to shoot. Attached File |
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I can see where you're coming from, 'cause I know where you've been and I can see where you're going 'cause I can see the direction you're headed in. I just don't know where the hell you're at right now.
I can see where you're coming from, 'cause I know where you've been and I can see where you're going 'cause I can see the direction you're headed in. I just don't know where the hell you're at right now.
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Originally Posted By fiftytencee: Right now, it's at around .35 inches. Attached File This is where mine needs to be for my EPT/MARC combo. If I adjust it out a little, maybe 2 turns, the bolt starts to get some binding... any more and it just locks up. |
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Originally Posted By ARKAR: We had been messaging before he posted. I believe he said it was doing the same thing with the screw ran in completely. Here's a picture of my A1 setup with the Cornfire. The screw is about .345 from the top of the screw to the trip. Also note the position of the trip and the lever. It runs practically 100% with good ammo. It's a blast to shoot. https://www.ar15.com/media/mediaFiles/50570/IMG_2148_jpeg-3689743.JPG When I switched to the MARC, I didn't change anything in the rest of my setup. First time I tried to rack the bolt it stopped HARD at about 3/4 of it's normal travel. Running the screw back in all the way was my sweet spot. |
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Originally Posted By shultz: All the way in should look like this. I measure about .160 for the jamb nut/screw head when flush together and flush against the trip. This is where mine needs to be for my EPT/MARC combo. If I adjust it out a little, maybe 2 turns, the bolt starts to get some binding... any more and it just locks up. Originally Posted By shultz: All the way in should look like this. I measure about .160 for the jamb nut/screw head when flush together and flush against the trip. This is where mine needs to be for my EPT/MARC combo. If I adjust it out a little, maybe 2 turns, the bolt starts to get some binding... any more and it just locks up. Originally Posted By ARKAR: We had been messaging before he posted. I believe he said it was doing the same thing with the screw ran in completely. I had an experience where the lock-up point varied substantially between uppers (same bolt, same trip, same lower, same charging handle), which is why I asked. Given tolerance stacking and that 22LR setups can be quite finicky, this seemed like an easy thing to try given the symptoms, but apparently this isn't the issue here. 🤷♂️ |
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Originally Posted By ARKAR: We had been messaging before he posted. I believe he said it was doing the same thing with the screw ran in completely. Here's a picture of my A1 setup with the Cornfire. The screw is about .345 from the top of the screw to the trip. Also note the position of the trip and the lever. It runs practically 100% with good ammo. It's a blast to shoot. https://www.ar15.com/media/mediaFiles/50570/IMG_2148_jpeg-3689743.JPG |
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| Speaking of trip advance set screws, does anyone have any tips on how to keep theirs set? I clean the channel, the set screw, and the inside of the little nut with brake cleaner, apply blue Loctite, reassemble and get the screw positioned where I want, then tighten the nut down as much as I can with a small adjustable wrench before I start getting scared that I'm going to round it off. Even so, mine keeps breaking loose and walking back in after 700-1,000 rounds. With the Atrius, I haven't really noticed a difference in firing rate or reliability, so it may not matter? |
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Originally Posted By lugnutwrench2: Speaking of trip advance set screws, does anyone have any tips on how to keep theirs set? I clean the channel, the set screw, and the inside of the little nut with brake cleaner, apply blue Loctite, reassemble and get the screw positioned where I want, then tighten the nut down as much as I can with a small adjustable wrench before I start getting scared that I'm going to round it off. Even so, mine keeps breaking loose and walking back in after 700-1,000 rounds. With the Atrius, I haven't really noticed a difference in firing rate or reliability, so it may not matter? If your set up functions the same with the screw walked back in why not leave it there? |
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Who here is using a FRT with a 22LR. What is your setup? (Page 6 of 11)
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