MK12 collar/brake and suppressor on different barrels?

KCode

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Mar 25, 2019
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I know the suppressor threads to the brake and mates up to the collar. But how exactly does it mount to the barrel? Do you HAVE to have a MK12 barrel? How are people mounting these suppressor setups on barrels that are less than 16 inches?
 
theres a step on the barrel that the rear coller seats against.
depending on the barrel you can get a custom one made or used to be able to if you emailed measurements to allen engineering.
it seems like hes maybe not doing a lot of that anymore? idk.
anyways i had one built to put my aem5 on a 14.5" socom barrel. those have a step in front of the gas block journal.
 
anyways i had one built to put my aem5 on a 14.5" socom barrel. those have a step in front of the gas block journal.

That's what I want! I want a OCM5 on a 14.5 barrel but I'm trying to figure out how. Can you pin and weld the MK12 brake? (I don't know how long the brake is though)
 
That's what I want! I want a OCM5 on a 14.5 barrel but I'm trying to figure out how. Can you pin and weld the MK12 brake? (I don't know how long the brake is though)
There’s an arfcom thread with all this info, though don’t they take kindly to Otter Creek.
 
Brake is 2”. If you drill it for a pin make sure the threads are chased properly.

IMG_5759.jpeg
 
So the collar and brake aren't gas block reliant at all other than the obvious the gas block cannot be between the collar and brake? How would handguard length be determined? Traditional flush thought is 1 inch less than the length of the barrel. So 14.5 = 13.5 rail or 16 = 15 rail.

How would you determine the handguard length with the MK12 setup? I'd like to run a Larue quad rail or maybe a DDM4
 
I would contact ADCO and go over what barrel and rail you'd like to use with an AEM5 or OCM5. He's done a bunch of one-off projects to support reflex AE cans over the years.

ETA: Or Wilson, as noted below.
 
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Pretty sure D Wilson will recontour barrels for this exact need to put a collar on to run the Ops Inc brake.

14.5" sounds fun. I love my 16" with an OCM5. It would be my go to gun for SHTF. Super versatile. Run it with a DBAL A2 and Surefire light.

77SMKs will fuck.
 

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Pretty sure D Wilson will recontour barrels for this exact need to put a collar on to run the Ops Inc brake.

14.5" sounds fun. I love my 16" with an OCM5. It would be my go to gun for SHTF. Super versatile. Run it with a DBAL A2 and Surefire light.

77SMKs will fuck.

Yep, this will be the ultimate SHTF setup. I never really even thought about it until I watched the video below. I'll be honest I did think about the 16 inch and not even worry about the pin and weld but I honestly would like to get it as 'short as possible' legally. 14.5 is such a perfect length for 5.56.

 
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Oh and I found this in 14.5 so we are pretty much there other than the pin and weld, have to find someone to do that good.



Looks like they offer the collar and brake as an option. They may do the pin/weld. Probably worth a call.
 
So I spoke with ADCO and they said they absolutely wouldn't touch it.

I also called D. Wilson and explained it to the girl that answered the phone. She said yea no problem. I expressed to her how different it would be vs a normal pin and weld and asked if she could double check with the gunsmith. She came back and said he said they could do it no problem. The same $60 as a normal pin and weld. I'm still a little skeptical it wasn't expressed the difficulty there could be. What do you guys think?
 
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This doesn’t seem like it would be that hard, unless I’m missing something. Drill a hole in the brake half way up the threads , clean the shavings with a file, chase the threads with the appropriate threading die. Inspect. Test fit on barrel and screw on a can to ensure there’s no issue.

Maybe talk with https://www.thoroughbredarmco.com/ as well. They make the cans now, and versions of the Gordon Carbine which would also need a pin/weld to be legal if not SBR.
 
If you have a govt profile barrel, I think Otter Creek has a collar for that to work: https://ottercreeklabs.com/product/m4-collar/

Arfcom probably hates on OC because "he stole Ron's design" despite not even remotely using the same internal baffle design (Ops Inc's patent was largely for baffle design), OC owner seems a bit cocky at times maybe?, and his instagram is kind of cringe to me personally.

OC seems to make good suppressors, and while AE was transferring to Trajectory Arms or whoever is doing the AEM5 now, it was nice to see someone making moderately clone correct suppressors for all of us suckers who can't stop simping over the looks of a properly kitted MK12.
 
If you have a govt profile barrel, I think Otter Creek has a collar for that to work: https://ottercreeklabs.com/product/m4-collar/

Arfcom probably hates on OC because "he stole Ron's design" despite not even remotely using the same internal baffle design (Ops Inc's patent was largely for baffle design), OC owner seems a bit cocky at times maybe?, and his instagram is kind of cringe to me personally.

OC seems to make good suppressors, and while AE was transferring to Trajectory Arms or whoever is doing the AEM5 now, it was nice to see someone making moderately clone correct suppressors for all of us suckers who can't stop simping over the looks of a properly kitted MK12.

Not related to that but guys correct me if I'm wrong here but does this OC OPS/AE Muzzle Brake not solve my problems above with pin and weld?
 

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Something to consider, most companies go off the original drawing for spacing from the threads to the collar step. On most of the cans I have seen this allows 2.5-3 full turns. Ron recommended I think 6 full turns . (My can shot fine with three turns and didn’t shoot loose)

If you pin and weld this before you know how many turns you’re going to get screwing the can on, if it’s short, you’re F’d as that collar won’t fit over the brake to set the shoulder back.

Might be best to have it all in one place to test for everything before you do any permanent work.


Could mean nothing to you. I have my barrels profiled for 6-10 turns on the can.
 
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Something to consider, most companies go off the original drawing for spacing from the threads to the collar step. On most of the cans I have seen this allows 2.5-3 full turns. Ron recommended I think 6 full turns . (My can shot fine with three turns and didn’t shoot loose)

If you pin and weld this before you know how many turns you’re going to get screwing the can on, if it’s short, you’re F’d as that collar won’t fit over the brake to set the shoulder back.

Might be best to have it all in one place to test for everything before you do any permanent work.


Could mean nothing to you. I have my barrels profiled for 6-10 turns on the can.

That is actually solid advice. I didn't think of that but you are 100% right
 
Something to consider, most companies go off the original drawing for spacing from the threads to the collar step. On most of the cans I have seen this allows 2.5-3 full turns. Ron recommended I think 6 full turns . (My can shot fine with three turns and didn’t shoot loose)

If you pin and weld this before you know how many turns you’re going to get screwing the can on, if it’s short, you’re F’d as that collar won’t fit over the brake to set the shoulder back.

Might be best to have it all in one place to test for everything before you do any permanent work.


Could mean nothing to you. I have my barrels profiled for 6-10 turns on the can.

Could you explain this more? Are you using the AEM5 and the SPR or M4 collar? I've ran into a few threads that say the brakes were originally shorter and are now longer, I'm wondering if this is the issue you are talking about. Do you mean the cans have changed or companies are changing the mounting pieces?
 
All of mine are mk12 collars. One has a Smith Enterprise flash hider which needed to have some taken off the back end to keep the front of the unit from bottoming out when installing with peal washers.

Here is how I understand it. Gene Barenett did the original five barrels and has the print still hanging in the Barrel Barn. The barrel these companies make are all basically based off that print. Not having actually been issued a mk12, my assumption is they used a small crush spacer or something along those lines to build the uppers in the issue rifles, but it’s an assumption.

When you cut the barrels to the original spec or the one from AEs website, it’s been my first hand experience across edit: FIVE barrels that you get less than or right at three turns. When I asked a couple end users they didn’t remember how many the turns the work guns had, so I called Ron and he advised 3 sounds right but he preferred 6 or so. (Going off memory, if Scout was still around I could look it up)

So, when we profile our barrels now we cut the “step” back a little.

I’ll have to check when I get home but I think the shoulder for the gas block was cut for a delta ring as well. It’s been about 5 years since I built a new one and probably 3 since I rebarrel so I’m a little fuzzy..
 
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More updates: WOA said they will not modify any finished barrels and they are not offering custom barrels currently. So that was bad news this morning.

However I had some better than good news this afternoon. On a whim I decided to call CLE and they apparently have exactly what I need! They do not have a 14.5 MK12 barrel however I was told their Recon 14.5 barrel would be exactly what I want and it has a cut for the collar. Even better news is they can, know how (explained it to me), and will pin and weld the MK12 muzzle device.
 
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That's awesome. Did they mention anything about the gas block they would use on that 14.5? I'm wondering how gassy a 14.5/mid will be.

That was not discussed and further CLE actually offers the 15.1 length barrel. I'm just getting into this so I'm sharing information with you guys as I learn it. But apparently the 15.1 barrel only exist because arfcom guys were begging for a barrel length that would leave the AEM5 flush with a KAC FF RAS. Now that the rail is no longer offered I don't see the point in going with the 15.1 barrel. However I also don't know what length rail would be used with a 14.5 setup, it could leave me at an odd length with a gap.

But to answer your question further, maybe an adjustable gas block would be beneficial. I don't really care for them but I've learned the AEM5 setup is gassy in general (even though I will be using a OCM5) so maybe a gas block like this https://suparms.com/750-adjustable-gas-block-stainless-steel-solid-set-screw-melonite-finish.html would be of use. Bleed off of gas will go out of the block and not the ejection port. However, again I do not know if that will make the setup louder or not.

There's still a lot of unknowns.
 
I know this post is a couple months old but did the OP check High Caliber Sales. Last time I emailed Kevin he said they could custom make a 14.5” Douglas barrel to work with the OPS INC style brake and OCM5. The only downside was the 4-6 month wait.
 
That was not discussed and further CLE actually offers the 15.1 length barrel. I'm just getting into this so I'm sharing information with you guys as I learn it. But apparently the 15.1 barrel only exist because arfcom guys were begging for a barrel length that would leave the AEM5 flush with a KAC FF RAS. Now that the rail is no longer offered I don't see the point in going with the 15.1 barrel. However I also don't know what length rail would be used with a 14.5 setup, it could leave me at an odd length with a gap.

But to answer your question further, maybe an adjustable gas block would be beneficial. I don't really care for them but I've learned the AEM5 setup is gassy in general (even though I will be using a OCM5) so maybe a gas block like this https://suparms.com/750-adjustable-gas-block-stainless-steel-solid-set-screw-melonite-finish.html would be of use. Bleed off of gas will go out of the block and not the ejection port. However, again I do not know if that will make the setup louder or not.

There's still a lot of unknowns.
OPEiRNFm.jpg


15.1" with a KAC handguard and AEM 5
 
So I spoke with ADCO and they said they absolutely wouldn't touch it.

I also called D. Wilson and explained it to the girl that answered the phone. She said yea no problem. I expressed to her how different it would be vs a normal pin and weld and asked if she could double check with the gunsmith. She came back and said he said they could do it no problem. The same $60 as a normal pin and weld. I'm still a little skeptical it wasn't expressed the difficulty there could be. What do you guys think?

Little late to the party, but she was correct, it’s not difficult to do at all.

Literally one extra step to cut a flat on the threads, so we are pretty unphased by this.
 
That was not discussed and further CLE actually offers the 15.1 length barrel. I'm just getting into this so I'm sharing information with you guys as I learn it. But apparently the 15.1 barrel only exist because arfcom guys were begging for a barrel length that would leave the AEM5 flush with a KAC FF RAS. Now that the rail is no longer offered I don't see the point in going with the 15.1 barrel. However I also don't know what length rail would be used with a 14.5 setup, it could leave me at an odd length with a gap.

But to answer your question further, maybe an adjustable gas block would be beneficial. I don't really care for them but I've learned the AEM5 setup is gassy in general (even though I will be using a OCM5) so maybe a gas block like this https://suparms.com/750-adjustable-gas-block-stainless-steel-solid-set-screw-melonite-finish.html would be of use. Bleed off of gas will go out of the block and not the ejection port. However, again I do not know if that will make the setup louder or not.

There's still a lot of unknowns.

I went this route because CLE had a 15.1” “recce” barrel on the clearance rack. I couldn’t find a KAC FF rail, so I bought a DD RISII and cut 1/2” off with a bandsaw. Touched it up with some of the dark brown krylon camo paint (matches perfect).

I wouldn’t do it again for the lack of rail selection that would work with this barrel length and can setup without being prohibitively expensive, requiring modification, or looking retarded. Next time will be a 16” from craddock and a 13” KAC URX4.
 

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I went this route because CLE had a 15.1” “recce” barrel on the clearance rack. I couldn’t find a KAC FF rail, so I bought a DD RISII and cut 1/2” off with a bandsaw. Touched it up with some of the dark brown krylon camo paint (matches perfect).

I wouldn’t do it again for the lack of rail selection that would work with this barrel length and can setup without being prohibitively expensive, requiring modification, or looking retarded. Next time will be a 16” from craddock and a 13” KAC URX4.

Jesus that is sick...