From Skeptic to Convert – ZRODelta Cowl Induction Brake Real World Testing and Results

ZRODelta CIB Muzzle Brake ReviewAnyone remotely acquainted with my philosophy when it comes to muzzle brakes knows how much I dislike them. Disdain would be the most common term used, although that remains understated. Most of my shooting career has revolved around duty as a Law Enforcement professional, protection, and self-defense applications where brakes are flat out dangerous. I still believe there is no place for a brake on any rifle designed for use in close proximity to anyone else or any duty application. Having suffered next to them at training and felt the effects in enclosed spaces they are nothing more than hearing loss machines. Attached to magnum or short barreled rifles their concussive effects are distracting at best, mostly annoying and can be debilitating.   There is a reason an entire study was completed by the military as to the long term health effects of flash hiders; muzzle brakes are just that much worse.

True, recoil reduction can be substantial making them a necessary evil on a magnum, especially true magnums like the 338NM, 338LM, 375 CT and the 50BMG based cartridges. Brakes are commonplace on what I call the “little magnums” like the 300 WinMag and 7mm Mag and undoubtedly contribute to hearing loss amongst many hunters. Anything smaller, hit the gym, save your hearing. Where muzzle brakes do have a place is competition, and is where this new ZRODelta Gen 2 6.5MM CIB (Cowl Induction Brake) was tested.

Precision Rifle Competitions

The last few years my precision shooting has gravitated toward the PRS style competitions. Challenging, they push your skills, test your limits, and are all around a pretty good time. Shooting long range remains a passion for me, not just work, so it occupies much of my personal training. It’s also the first competition oriented event where my professional rifles were not used and dedicated competition guns were assembled. So it is precision rifles that have brought me to muzzle brakes and testing this ZRODelta CIB.

But could this skeptic be convinced to use a muzzle brake? As a long time suppressor user, I’ve argued that for the most part silencers do the trick, but they too have their issues. It’s kind of split in the community so it was time for me to complete my idea of a comparison to see if muzzle brakes are really worth the pain.

ZRODelta CIB brakeComparison Testing

 Others have done the whole lab testing thing with brakes; in fact it was their results that guided me to the two brakes used in my testing. If your latest greatest favorite brake is better, then my results should translate. These are the two of the most popular muzzle brakes among those winning on either the PRS or NRL tours. Besides, labs are not my thing; I hate indoor ranges and won’t step into one unless I have to. After too many years shooting in confined spaces, I find indoor ranges too loud, too pressure intensive, and restrictive. My shooting occurs outdoors in what nature offers, and under real conditions. So, this is not some test with accelerometers or meters, just me, shooting guns I use for long range, both competition and hunting. Definitive? Not even close, but hopefully at least as instructive.

For this series of tests I used four rifles, two bolt guns and two semi-automatics:

  • My bolt action Surgeon Scalpel chambered in 260 Remington. It’s my go to competition rifle where the 6CM is not suited. It’s also one of my hunting rifles. A Proof Research 26” Carbon Fiber wrapped barrel sits in an Accuracy International AX stock.
  • Most bolt gun testing occurred on my A. Precision. It is a dedicated competition rifle using their Tempest action, very fast, very accurate, very light. It uses 24” 6 Creedmoor chambered Proof Research barrel and a McMillan A5 stock.
  • One semi-automatic was a 6CM build of mine.
  • Another semi-auto was a Modern Outfitters MC7 in 260 Remington
  • The last semi-auto was a Dark Storm Industries DS-10 chambered in 6.5 Creedmoor using a 24” Stainless steel heavy (very heavy) barrel.

Each rifle was tested with each device: two muzzle brakes and two suppressors. Along with the ZRODelta I used an APA Little Bastard in 6.5mm. Other reputable testing placed these two at the top at the top of the brake field by a pretty wide margin. Since my test was not a “comparison of muzzle brakes,” but more about how they impact the shooting experience under real conditions I simply opted to test using the two overall highest rated brakes, easily the two most seen at events on winning rifles.

Suppressors are a different challenge. Most cause the first round recoil to be different, generally more of a push. It’s what keeps many top tier competitors away. The whole idea is to have the muzzle move as little as possible, and the first round is the most critical. You need to be able to watch your hits. So, I used the two lowest back pressure intensive suppressor designs out there. Anything else will likely have a greater effect; this is the best case scenario. The NG2 Defense MAXFLO 3D and the OSS both have the least back pressure so far. My OSS is old, it’s a Gen 4 so it is not a direct comparison, but it does have very little first round push, far less than the other dozen standard designs in my inventory.

ZRODelta muzzle brake for precision rifleSome testing was done off the bench, or prone, but anyone can keep a barrel steady under those conditions. Most was done from unconventional and unsupported positions. Shots were fired from rocks, trees, barricades, awkward angles, inside a tube, and from a tripod. Ranges were from 400 to 1000 yards and occasionally at 1308 yards. The least muzzle movement was the goal, enabling me to watch my shots at distance so corrections could be clearly made. After that it was about overall comfort and distraction from blast or concussive effect.  Since most courses are one shooter at a time it really is less about the guy next to you in a competition. And I would never shoot without hearing protection so that was of less concern, but still a consideration, mostly in case your hearing protection slipped under adverse conditions.

Muzzle Movement

When it comes to muzzle movement the brakes win hands down. It was especially true on the semi-automatics. Either muzzle brake on the Semi’s in 260 Remington, 6 Creedmoor or 6.5 Creedmoor all but eliminated muzzle movement, even with some pretty hot loads. On the very heavy DS-10 it was like shooting a suppressed 5.56mm carbine. Granted, these are very well tuned using the best parts you can buy, but you can literally watch your hits at 100 or 1300 yards. Compared to other more “tactical” brakes the difference is striking. Establish a solid position and the guns might as well be in a vice, free from recoil. In unsupported positions there is some push, but so little you can stay on target the entire time. If you compete with an AR, use one of these.

My preference is for the ZRODelta mostly due to a noticeable lack of pressure and blast at the shooter. Loud for sure, and you can feel the concussion, but very little seems to go back at the shooter. For me this is critical as I find any blast towards me distracting and flat out annoying.

ZRODelta muzzle brakeBolt rifles performed the same. Even under free recoil, they easily had the least amount of barrel movement. It’s pretty easy to see why so many use muzzle brakes. They provide a real advantage in holding on target through the entire shot sequence. The ZRODelta was the best on every rifle.


OSS suppressor vs muzzle brakeIn spite of their marketing, both suppressors had first round push; nothing like conventional designs, but it was there, especially on that very first round down the barrel on the bolt rifles. Recoil in general was more noticeable compared to the brake, although both were much better than conventional brakes, flash hiders or suppressors.

The greatest effect was also felt on the semi-automatics. Using the OSS on the 6CM, I wondered if it went off, and the over the barrel mounting keeps the platform a few inches shorter. Using the MAXFLO 3D on the Modern Outfitters gun is all but transformational. Recoil is noticeably reduced, the barrel moves very little, and any first round push is sucked up by the bolt movement. Overall, the muzzle brakes keep the barrel steadier.

There are other serious considerations, especially reliable operation. Neither suppressor affected how the guns ran, and the AR’s were much cleaner using these instead of traditional suppressors built with baffles. Not a big deal on a bolt gun, but on an AR it’s huge. Furthermore, lacking baffles these two suppressors don’t trap as much gas so there is no increased bolt lift. There was no issue running the bolt as fast as desired. Both suppressors add length and weight, considerations for competition. Neither was particularly quiet but they are 30 caliber suppressors. On the border of hearing safety, they are immensely quieter than any of the brakes.

With zero blast at the shooter and no concussive effect there is no distraction. The suppressors are also much better to shoot in tubes or where blast can bounce off the side of obstacles.

Finally, if your hearing protection does slip off you notice it, but the damage the brake will do is eliminated. It’s not uncommon during some events to end up in a position where your external hearing protection slips off, so suppressors are great here. It’s also a really good reason to double up hearing protection no matter what. Hearing damage is permanent and cumulative, another reason many use a suppressor.

NG2 SuppressorConclusions

 Given these two top muzzle brakes, the APA Little Bastard and ZRODelta CIB, the latter is sitting on my G. A. Precision rifle for the next competition. The biggest difference I experience between the braks was the amount of blast directed at me. The ZRODelta was best. It’s also smaller and a bit lighter.

Yep, for a strictly competition rifle I am a convert.

I tested everything on this GAP rifle under all kinds of conditions and the ZRODelta CIB was hands down the best overall for the competitive environment. Both brakes mitigate recoil well. If there is a measured difference I could not feel it, not on any of the rifles, but comfort with the CIB was better. On the AR’s it was sixes, although the CIB still had less felt muzzle blast. For me at least, that is a moot point since the suppressors will stay on my semi’s.

Both suppressors worked well, although the OSS is an older design. Would love to have tested a new one but OSS has consistently refused to submit any of their suppressors for my testing. Familiar with both designs since their introduction, the only similarity is they are suppressors without baffles. Both try to get to the same place in completely different ways. Priced about the same, they seemed to work better on different rifles. The NG2 mated to either of my 260 Remingtons, the Modern Outfitters MC7 or the Surgeon Scalpel, is game changing. Substantial recoil reduction, no change in operation, it’s even pretty quiet. The OSS seems to work better on the 6CM, especially the semi, and it only adds a couple inches to length. Since it is dedicated mostly to longer range varmint eradication, the OSS is perfect. NG2 is constantly improving their design. They are even working on a dedicated 6mm suppressor for precision rifles so it will be interesting to see how that works out.

Bottom Line

 This was no easy conversion, my disdain for muzzle brakes is still firmly in place. You will never see one on any working rifle I deploy, or even multi-gun competition rigs. But, like all tools they are best suited to particular tasks. This ZRODelta CIB was impressive enough to become my “go to” device on the dedicated competition precision rifle. While I have zero likelihood of winning any PRS or NRL event, losing is not something I enjoy, and the lack of barrel movement does provide an advantage, especially when less than steady on small targets at longer range. I like to attend these events with the idea of shot placement as a priority, order of placement minimally important and the CIB gets that done.

ZRODelta CIB Muzzle Brake ReviewFor some, the suppressor is still the way to go and in most instances that’s me. Both the Surgeon and the semi-automatics will stay suppressed. Right now length and weight are a big deal for some. It’s hard to maneuver in and out of barricades with a 26” barrel and another 7-10” suppressor. But companies are starting to see the market for a “PRS” style suppressor, and that may take me right back. But for now, the ZRODelta Gen 2 CIB muzzle brake is the ticket for my competition precision rifle.

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