Mk12 Holland 16" Barrel Kit For Mod H Rifles

generally in-stock, and will ship in 2 to 4 weeks, allowing for coating. In rare event that we are waiting on barrel shop, we will place in backorder status
AEM Collar Selection:
in comments mention SHORT or LONG, or we default to first available.

Mk12 Holland 16" Barrel Kit For Mod H Rifles With Ops Inc./AEM Hardware Ready to Install


Ready to install barrel, Ops Inc. brake, and collar.

Let's face it, when we are building a Mk12 we want everything just right. Charlie's is here to help with barrels that will work wonders for you, already coated to spec, and we have included the Mk12 barrel and the Allen Engineering long (optionally short) collar, brake, and thread protector. You benefit from our research, our testing, and clone ready barrel.

Just add this setup to your clone receiver setup, or if you are looking for a specialty Mk12 inspired look, have at it. Oh, you might also need the right handguard, optic, stock, bipod, and rings.  

We have done the research. This Douglas 16" barrels fits the Ops Inc or Allen Engineering collar and brake on the barrel, and then attach the AEM-5/Ops Inc. #12 suppressor on the barrel with collar and brake setup.

To get the suppressor of a Mk12/Ops Inc/AEM-5 aligned properly is a very delicate and technical task. The suppressor rests on on the collar, but then is threaded inside the suppressor onto the external threads on the brake. There is a certain number of turns that are needed for all this magic to happen and the suppressor to perfectly rest on the collar, and be securely fastened to the threads on the brake. 

If you want to build your Mk12 Mod H to be historically correct, then we are your huckleberry. We are offering this Douglas 16" 1:7 twist Stainless Steel barrel in traditional gray or FDE. This barrel has been custom chambered and profiled by Compass Lake Engineering, then custom coated with GunKote (Flat Gray) by Potomac Armory. This is for the purist. This is 100% clone correct. If you are looking for perfection, this is your barrel. Charlie's has spent time at Frank's shop at Compass Lake. These guys do magic with barrels, and Frank noted that the 16" barrel has caused issues over the years with excessive gas port erosion, but he has not seen that with Douglas. You might not know Douglas for barrels, but if you are looking for perfection in your Mk12 build, you will want Douglas, and you will want the craftsmanship that Charlie's brings you with Douglas, Allen Engineering, Potomac Armory, and traditional gray GunKote, all in one package. Now, if you don't want to be 100% clone correct, we also offer the barrel coated with Cerakote (FDE). Both look great.




Enjoy with confidence.

Specifications - Each Kit Contains:

  • An SPR profiled barrel suitable for a Mod H build, with an M4 barrel extension, drilled gas port, and crowned and threaded muzzle at 1/2"-28 threads.
  • Your choice of an AEM collar and brake kit in short or long. Short is standard for the Mod H builds; however, you can request to substitute for a long collar (just add that in the order notes).
  • Inspected and packaged in Mil-Spec (blue) anticorrosive VCI plastic tubing by Charlie's Custom Clones.
  • 30-day money back guarantee. Since we are sponsoring this. If you are not happy, and have not shot it, return it for a full money back refund.
  • No gas block is included. The kit is unassembled, as you will need to insert the barrel nut, for the handguard or rail of your choice.  We wanted to do it all, but the fact is you need to get the barrel nut on first, and then the gas block. 
  • Instructions are very detailed as to how to time the Allen brake.


If you are building a Mod H, you will want to get the PRI Gen1 flip-up sights with the cross-bolt installation.


Charlie's also offers installation of the complete kit with the gas block and your barrel nut, or the entire upper receiver with your rail for an additional feeNote that to assemble the barrel kit, we will need the barrel nut that you will be using, or you will need to buy the barrel nut from us. The barrel nut must be installed before the installation of the gas block and the collar and brake.  Most customers will choose to purchase the rail with the barrel if Charlie's is installing the kit, but if you have a rail, you can send us the barrel nut separately.

For the Mod H, we will install the PRI folding gas block and time the cross bolt pins, and use a thread locker on the screws, but you will still be able to remove or adjust the hex head screws, which was often used by snipers to adjust for windage. The collar will be properly installed, and the brake will be timed and set in place with Rocksett. The service fee for the Mod H is $100, and you can add that here, and let us know the reason for adding shop service in the comments when you check-out.

Note on availability and pricing

On pricing, some barrel kits might seem high, but keep in mind, you are getting AEM muzzle kit, the barrel coating and Charlie's selection and handling, all in one place. We have invested a lot of time and inventory and research into Mk12 barrels. You can count on getting the right barrel. On delivery timing, some barrels are in stock, and others need to be made, not to order, but in batches, and also tested and coated, so plan on a good 5 weeks for your barrel delivery. Some will ship in 1 or 2 weeks, some in 5 to 8 weeks.