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Posted: 2/16/2026 2:46:47 PM EDT
[Last Edit: maynardjay][Edited]
| Has anyone had a chance to check out an MCQ-2 yet? I'm reading that the only differences to the MCQ-1 are weight and duratibity, yet I'm seeing shot show videos and KAC publications that indicate new internal geometry that are creating dramatic performance increases. |
I have one in jail right now. I checked it out the other day and the internals look different but that is the first time I've looked at a 3d can. I asked Knights if I'll have a spacing issue with my 11.5 cqb upper and they claimed the collar has been shortened to help with fitment issues but I have not confirmed yet.
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Mcq1 = 154 dbl 1 meter left, 143 dbl at ear Mcq2 = 148 dbl 1 meter left, 141 dbl at ear With either of these you’re going to be running hearing protection. In my opinion that’s very close to each other because how high on the scale they are and I would buy the cheapest of the two. I personally run the QDC/mcq-prt on an 11.5” sbr and think it’s great but I’m not trying for max suppression, just taking the edge off and killing flash. Now, I’m not to sure how to define the mcd*s which is flash but mcq1 is 1.23 vs 0.61 on first round flash. The second round is about the same at 0.24 vs 0.23. If someone could explain this scale I would appreciate it. |
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Originally Posted By seanhowies: I have one in jail right now. I checked it out the other day and the internals look different but that is the first time I've looked at a 3d can. I asked Knights if I'll have a spacing issue with my 11.5 cqb upper and they claimed the collar has been shortened to help with fitment issues but I have not confirmed yet. https://i.ibb.co/jkyscwhr/20260214-133101.jpg I don’t have my Gen 1 in front of me but your collar does look shorter. Looks awesome! |
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Originally Posted By dmtsc: Mcq1 = 154 dbl 1 meter left, 143 dbl at ear Mcq2 = 148 dbl 1 meter left, 141 dbl at ear With either of these you’re going to be running hearing protection. In my opinion that’s very close to each other because how high on the scale they are and I would buy the cheapest of the two. I personally run the QDC/mcq-prt on an 11.5” sbr and think it’s great but I’m not trying for max suppression, just taking the edge off and killing flash. Now, I’m not to sure how to define the mcd*s which is flash but mcq1 is 1.23 vs 0.61 on first round flash. The second round is about the same at 0.24 vs 0.23. If someone could explain this scale I would appreciate it. Peak DB means very little, especially without duration, but 6 DB is significant given it's logarithmic. The peak DB on the MCQ-1 would be 4x more intense and would sound twice as loud as the MCQ-2. I'm guessing they achieved this by throttling pressure a bit more, so maybe the back pressure is higher, the published ear numbers nod to this, and/or it's loud for a longer duration with a flatter curve? It'll fun when someone gets their hands on both. |
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I got mine the other day and ran a couple mags through it when I picked it up swapping back and forth between mcq1/2. MCQ2 seems like less gas but the MCQ1 already did such a fantastic job it was hard to tell. Its quieter, but still loud. First round pop/flash way better. Overall flash better. (same ammo, 55g fiocchi 11.5 barrel) I am happy with both. If I was buying for the first time I would choose mcq2 over the 1. @Jack_L will the mcq2 work with the XC 2 port when its released? |
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Originally Posted By maynardjay: Peak DB means very little, especially without duration, but 6 DB is significant given it's logarithmic. The peak DB on the MCQ-1 would be 4x more intense and would sound twice as loud as the MCQ-2. I'm guessing they achieved this by throttling pressure a bit more, so maybe the back pressure is higher, the published ear numbers nod to this, and/or it's loud for a longer duration with a flatter curve? It'll fun when someone gets their hands on both. Awesome, you answered your own question with just a little bit of information I found on the internet. I run Hornady 75 gr SBR ammo in mine and at night I don’t notice any flash that’s concerning, but the ammo is designed to mitigate flash. |
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Originally Posted By dmtsc: Awesome, you answered your own question with just a little bit of information I found on the internet. I run Hornady 75 gr SBR ammo in mine and at night I don’t notice any flash that’s concerning, but the ammo is designed to mitigate flash. Originally Posted By dmtsc: Awesome, you answered your own question with just a little bit of information I found on the internet. I run Hornady 75 gr SBR ammo in mine and at night I don’t notice any flash that’s concerning, but the ammo is designed to mitigate flash. I didn't mean to sound flippant, I appreciate your feedback. Originally Posted By dmtsc: Mcq1 = 154 dbl 1 meter left, 143 dbl at ear Mcq2 = 148 dbl 1 meter left, 141 dbl at ear With either of these you’re going to be running hearing protection. In my opinion that’s very close to each other because how high on the scale they are and I would buy the cheapest of the two. I personally run the QDC/mcq-prt on an 11.5” sbr and think it’s great but I’m not trying for max suppression, just taking the edge off and killing flash. Now, I’m not to sure how to define the mcd*s which is flash but mcq1 is 1.23 vs 0.61 on first round flash. The second round is about the same at 0.24 vs 0.23. If someone could explain this scale I would appreciate it. It's interesting they were able to achieve more suppression with less back pressure. Based on pictures it looks like they gave themselves a bit more runway by reducing the collar and increasing length overall slightly. What barrel length were you using? |
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Originally Posted By dmtsc: Now, I’m not to sure how to define the mcd*s which is flash but mcq1 is 1.23 vs 0.61 on first round flash. The second round is about the same at 0.24 vs 0.23. If someone could explain this scale I would appreciate it. NATO AEP 4785 Flash Measurement Methodology: 1. The visible and IR emission from a flash is measured by an array of radiometers. 2. Instantaneous luminous intensity (Iv) is integrated over the duration of the flash to give luminous energy (Qv, reported in millicandela seconds). 3. Luminous energy is proportional to perceived brightness. Millicandela seconds=mcd*s |
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Originally Posted By dmtsc: Thanks Jack_L Wanted to give a little info here. Traditional suppressors will show a "first round pop" with higher flash and SPL than successive shots. "Good" older suppressors will show a first round flash of around 10-12 mcd*s, with successive shots at around 2 mcd*s. |
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Originally Posted By HAMBURGERATTACK: You gon need that 5.56 QDC Open Brake XC - sorry about the terrible terrible image link.... https://i.imgur.com/8vhF4Y9.png?1 Where is that available? Knights is going to send me a shorter collar. |
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Originally Posted By HAMBURGERATTACK: no-one has them in stock yet but KAC and rooftop both have OOS sale pages up for it. Originally Posted By HAMBURGERATTACK: Originally Posted By seanhowies: Where is that available? Knights is going to send me a shorter collar. no-one has them in stock yet but KAC and rooftop both have OOS sale pages up for it. I was told three month from a VERY reliable source. |
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Originally Posted By seanhowies: Will they just be brakes or 3 prongs also? Originally Posted By seanhowies: Originally Posted By agnisco: I was told three month from a VERY reliable source. Will they just be brakes or 3 prongs also? That I wasn’t told. Hopefully both for those that don’t shoot suppressed full-time and don’t want giant fireballs out the front of their 11.5. |
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Originally Posted By HAMBURGERATTACK: You gon need that 5.56 QDC Open Brake XC - sorry about the terrible terrible image link.... https://i.imgur.com/8vhF4Y9.png?1 Originally Posted By HAMBURGERATTACK: Originally Posted By seanhowies: Picked up my suppressor and unfortunately it still didn't fit the 11.5 CQB upper. You gon need that 5.56 QDC Open Brake XC - sorry about the terrible terrible image link.... https://i.imgur.com/8vhF4Y9.png?1 I have a MCQ-1 and of course the first thing I noticed is that it didn’t fit my mod 2 11.5. But, I bought it for the KS1 which is still unavailable like 2+ years later (I did not expect to get the suppressor before I got the rifle!) and now there is a MCQ-2 lol. So I just use it on a different rifle altogether. Whatever. So now the fix to use it on the mod 2 11.5 is a new muzzle device? Or a shorter collar? Or something else I need to buy? Am I missing anything or did that about cover it? |
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Originally Posted By ChandlerKJ: I have a MCQ-1 and of course the first thing I noticed is that it didn’t fit my mod 2 11.5. But, I bought it for the KS1 which is still unavailable like 2+ years later (I did not expect to get the suppressor before I got the rifle!) and now there is a MCQ-2 lol. So I just use it on a different rifle altogether. Whatever. So now the fix to use it on the mod 2 11.5 is a new muzzle device? Or a shorter collar? Or something else I need to buy? Am I missing anything or did that about cover it? If you want to do it the right way and don’t plan on using a shroud, get the short collar from KAC free of charge. If you want to do it the right way and plan on using a collar, wait for the new muzzle device to come out. If you want to do it the ad hoc way so you can use a shroud with current muzzle device, either shim it out or figure out a way to shorten the rail by about .25”. |
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I posted a bit about this in the other thread going on about suppressor clearance, but after a recent conversation here is what I got. Unknown ETA on new muzzle devices. Short collars, at least in black, are out of stock with no projected return date. Shimming a MOD2 will void the warranty on the suppressor based on space they stated is required, and is not at all recommended. URX6 replacement is at a two week turnaround. I wound up going with the URX6 option, and got it in the mail Friday. Was hoping to just snag a short collar, but happy with this. One understandable thing I did learn, is that they will not work on guns with any aftermarket parts sent. I don’t have an OEM charging handle, so they won’t test fire after reassembly. In the future, I’ll keep better track of that stuff in the event of an RMA just for peace of mind. My dumbass had to go back into UPS to pull the charging handle so they wouldn’t immediately return it due to having non-OEM parts haha. Was in a hurry to get it out and stripped optic, arca, PEQ, etc… just forgot to pull the charging handle, and didn’t want to piss away over $100 on shipping just to have them refuse an RMA. Overall the service I received was prompt, very good, and all questions were answered. |
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Originally Posted By agnisco: If you want to do it the right way and don’t plan on using a shroud, get the short collar from KAC free of charge. If you want to do it the right way and plan on using a collar, wait for the new muzzle device to come out. If you want to do it the ad hoc way so you can use a shroud with current muzzle device, either shim it out or figure out a way to shorten the rail by about .25”. Originally Posted By agnisco: Originally Posted By ChandlerKJ: I have a MCQ-1 and of course the first thing I noticed is that it didn’t fit my mod 2 11.5. But, I bought it for the KS1 which is still unavailable like 2+ years later (I did not expect to get the suppressor before I got the rifle!) and now there is a MCQ-2 lol. So I just use it on a different rifle altogether. Whatever. So now the fix to use it on the mod 2 11.5 is a new muzzle device? Or a shorter collar? Or something else I need to buy? Am I missing anything or did that about cover it? If you want to do it the right way and don’t plan on using a shroud, get the short collar from KAC free of charge. If you want to do it the right way and plan on using a collar, wait for the new muzzle device to come out. If you want to do it the ad hoc way so you can use a shroud with current muzzle device, either shim it out or figure out a way to shorten the rail by about .25”. Awesome, thank you for the information. I guess I somehow missed the bulletin about the 'short collar from KAC free of charge'. Was that posted on their website? Simple as emailing them and providing the serial of the unit you want a collar for? Seem like that is an expensive fix for the clearance issue. I suppose I would have included in the description a: ' *Does not fit on a MOD 2 11.5" upper with existing muzzle devices or without a separate short collar which is no charge but must be requested (usually out of stock as well)' |
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Originally Posted By ChandlerKJ: Awesome, thank you for the information. I guess I somehow missed the bulletin about the 'short collar from KAC free of charge'. Was that posted on their website? Simple as emailing them and providing the serial of the unit you want a collar for? Seem like that is an expensive fix for the clearance issue. I suppose I would have included in the description a: ' *Does not fit on a MOD 2 11.5" upper with existing muzzle devices or without a separate short collar which is no charge but must be requested (usually out of stock as well)' The way I figured it out is our department bought eight Mod 2 CQB SBR and eight PRT suppressors. We received them all while KAC was transitioning to notched upper receivers for the URX6, but the URX6/KS series were not yet being shipped. Also, they were no longer making the original QDC suppressors, so the PRT line was our only choice. So our factory Mod 2 CQB SBR arrived with notched upper receivers and the URX4. The CRS/PRT suppressors they sold and shipped us would not lock all the way. We received an email from KAC shortly after receiving the guns and suppressors asking to send the suppressors back for a QC clearance check and explained the then discovered incompatibilityissue between the PRT suppressors and URX4, as well as some options to correct the problem. We sent all the upper receivers back and had the URX6 installed. They sent everything back and all was good. It was shortly thereafter that I remember KAC explaining the problem publicly somewhere, probably on here somewhere, as the suppressors started to reach the commercial market, and offering people the free collar. This was the option if you wanted to safely use the PRT suppressors with a URX4. The other option was to send you upper in and pay to have it upgraded to a tabbed upper receiver and URX6, which probably would’ve been $700+. I ended up getting the free collar so I could use my personal MCQ with my CQB Mod 2. I’m not sure if I’ll ever use a collar, but if I do I’ll have to buy the new muzzle device and swap the collar back out. Looks to me like the “short” collar is even a little shorter than the collar on the original QDC suppressor, as seen in the picture below comparing the QDC, “short”, and PRS collars. Side note, the next six compete guns we received about 18 months ago were complete KS-3 rifles and PRT suppressors. They’ve proved to be an amazing system thus far. Attached File |
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Originally Posted By ChandlerKJ: Awesome, thank you for the information. I guess I somehow missed the bulletin about the 'short collar from KAC free of charge'. Was that posted on their website? Simple as emailing them and providing the serial of the unit you want a collar for? Seem like that is an expensive fix for the clearance issue. I suppose I would have included in the description a: ' *Does not fit on a MOD 2 11.5" upper with existing muzzle devices or without a separate short collar which is no charge but must be requested (usually out of stock as well)' I contacted Knights mid last week and they are sending me a black collar for mine. I have not received shipping notification yet but was told it would be shipping this coming week. |
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Originally Posted By ChandlerKJ: Awesome, thank you for the information. I guess I somehow missed the bulletin about the 'short collar from KAC free of charge'. Was that posted on their website? Simple as emailing them and providing the serial of the unit you want a collar for? Seem like that is an expensive fix for the clearance issue. I suppose I would have included in the description a: ' *Does not fit on a MOD 2 11.5" upper with existing muzzle devices or without a separate short collar which is no charge but must be requested (usually out of stock as well)' Originally Posted By ChandlerKJ: Awesome, thank you for the information. I guess I somehow missed the bulletin about the 'short collar from KAC free of charge'. Was that posted on their website? Simple as emailing them and providing the serial of the unit you want a collar for? Seem like that is an expensive fix for the clearance issue. I suppose I would have included in the description a: ' *Does not fit on a MOD 2 11.5" upper with existing muzzle devices or without a separate short collar which is no charge but must be requested (usually out of stock as well)' For a free collar, they want proof of MOD2 CQB upper ownership such as a timestamped photo per my phone conversation last week. Originally Posted By seanhowies: I contacted Knights mid last week and they are sending me a black collar for mine. I have not received shipping notification yet but was told it would be shipping this coming week. You must have snagged one of the last ones! By Friday morning, they were OOS with no projected return date. |
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Originally Posted By TNW: For a free collar, they want proof of MOD2 CQB upper ownership such as a timestamped photo per my phone conversation last week. You must have snagged one of the last ones! By Friday morning, they were OOS with no projected return date. Spoke too soon, I checked in on the shipping and was told they are waiting for more stock. |
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Originally Posted By agnisco: I waited about two months, maybe a little longer. That was about a year ago though. When they have them, they ship in like a week but it definitely takes way longer once they run out. I also heard from them that they'll go for months with no one asking and then have twenty people hit them in a week so it's not super easy to plan for. |
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Originally Posted By seanhowies: I was told they expect to get more in later this week to get painted and hopefully ship towards the end of next week. Please keep us posted if this happens. Not the word I got (why I went with URX6 instead of collar). If there are delays with the URX6 route and the collars come back, I’ll just do that. Trying to knock this out expeditiously because of a move and some other major movements. |
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I ended up picking up an MCQ-2 for a CQB Mod 2. When timing my flash hider, I just used a slightly thicker shim, maybe 1/32". It locks with room to spare. I understand this may not be optimal, but while you're waiting for a new collar you can definitely use it. I don't think I'll bother with getting a new collar, but I think I'll primarily use it on a 14.5. It's a loud silencer, but it is for sure a silencer. I've heard some people say it's a blast forward device and a flash hider. That is not true. Compared to a CAT KK, it's a good bit louder (rough estimate 30%, maybe more) with substantially less back pressure. I'm wearing ear plugs shooting outdoors under cover, so take that with a grain of salt. I took a shot unsuppressed to give myself a baseline, and the MCQ-2 is much more pleasant than unsuppressed. The blast chamber geometry is fascinating. It has distal venting and three internal prongs that essentially make the flash hider 6 prongs. Past the prongs, it is stepped into three sections. Half is solid, 25% is stepped and solid, 25% is stepped deeper into the silencer. |
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