Its not every day that I get to write about a cartridge that I remember coming out, but today is one of those. It was twenty something years ago, I was a much younger fella recently married and a son on the way when I first learned about the 6.5 Grendel. Even back then 6.5’s were hot, so when I heard about the 6.5 Grendel I paid attention.
The little Grendel came from Alexander Arms, and the whole idea was to put higher Ballistic Coefficient (BC) bullets into an AR-15. Bumping up the case size was also necessary in order to get these 6.5 Bullets up to a respectable speed. All this to create a cartridge that would make the AR-15 more lethal at distances beyond 500 yards or more.
The popularity of the Grendel has led to similar cartridges gaining fame as well. The 6 ARC has become extremely popular for similar reasons, and now the 22 ARC is following its footsteps.
22 ARC, 6 ARC, and the 6.5 Grendel
6.5 Grendel Dimensions
The 6.5 Grendel inherited a similar volume from it PPC/220 Russian parent case, the case volume is approximately 35 grains of water. Typical Grendel powder charges run between 20-ish and 30-ish grains of powder, depending of course on the powder and bullet choice. These mild charges are not too different from charges used in the .223 or other comparable cartridges. This allows the 6.5 Grendel to propel 100-140 grain bullets up to velocities like 2300 to 2600. These are some pretty general numbers, that obviously are subject to change.
Left to Right: 308 Winchester, 6.5 Grendel, 223 Remington
The odd size of the Grendel case has some other consequences as well. With its .449 bolt-face it falls between the .223 bolts used in most AR-15 rifles and the very common 308 sized bolt-face in larger rifle platforms. Luckily due to popularity of the Grendel and similar cartridges, this has become less of a problem. 7.62×39, .224 Valkyrie and others have made the midsized bolt-face more mainstream.
Additionally, due to its shape and proportions, the Grendel requires a different magazine to feed from AR rifles. There are a few different options out there including followers and complete mag-housings that have been altered to fit the Grendel and its offspring.
My Test Rifle
The rifle featured in this article for testing purposes is a Bear Creek Arsenal bolt-action upper. A handy and cost effective way to convert from one firearms type to another. It features one of their eighteen-inch heavy barrels and threaded 5/8-24 which fits perfect for my suppressor. The 1:8 twist works great with bullets commonly loaded for the Grendel. I used a Maven RS.3 5-30X50 scope which was probably a little more than necessary, but welcome.
Part of the idea behind the Grendel was improved ballistic performance from the AR-15 rifle. With 5.56/.223 chambered rifles, most were shooting bullets from 55grains up to 75-80 grains. Which can be very useful for a great many things, but at 800 yards they have significantly deteriorated performance. That is where the Grendel comes in, even with a light for caliber bullet like a 123 grain 6.5, the Grendel far exceeds even the heavy .224 bullets. For comparison, a couple loads shown below; an average and heavy 5.56 load compared to an average and heavy Grendel load.
Load Data
Velocity/Energy @400yds
Velocity/Energy @800yds
5.56 55gr FMJ 3250 FPS
1800fps/395lbs
1000fps/120lbs
5.56 75gr BTHP 2910 FPS
2025fps/680lbs
1340fps/300lbs
6.5 Grendel 123gr 2450 FPS
1875fps/965lbs
1380fps/520lbs
6.5 Grendel 140gr 2330 FPS
1880fps/1100lbs
1475fps/680lbs
The Grendel loads can have thirty percent or more energy at further distances, which could be vital when incapacitating a target. While velocities are comparable, the energy of the heavier bullets carries further, and better.
Making brass for the little Grendel has come a long way from forming your own from something else. Whether it be Hornady or Starline, you can get some great brass for the Grendel. You can even get Lapua 6.5 Grendel cases now, so you know its serious.
Many of you are aware of my affinity for Desert Tech rifles, and if you are reading this you’ve likely seen much of my content about the various rifles. Today I am diving down another custom project similar to one I’ve done in the past. I made a custom barrel for my MDRX in 6mm ARC years ago, and today I am bringing you the story on how I went about making another custom, my Desert Tech WLVRN 6mm ARC project.
Because of the extremely satisfying results with my MDRX, I became quite fond of the 6mm ARC cartridge and have since gotten more of them. It was also a natural choice for me when I got my Desert Tech WLVRN, of course this would again require me to make my own. Today I’ll go over how that went.
the 6 ARC WLVRN left of the 6 ARC MDRX
The Desert Tech WLVRN
The Desert Tech WLVRNis the latest generation semi-auto bullpup, a direct descendant of the MDRX. Both of them being multi-caliber piston operated carbines. They share a great deal of parts and features, but they are also very different. The barrel mounting system is different, as are the barrel extensions, bolts, receiver and more. Perhaps the best difference between the two in my opinion, is the larger clamping-surface that holds the barrel. Part of that is because the trunnion is machined into the aluminum receiver, getting rid of the steel barrel block. Additional other steel parts were also removed, greatly reducing the weight of the rifle. The machined-in trunnion also makes the WLVRN return to zero when switching barrels. This was something aspired to by the MDRX but was never consistent.
I bought my WLVRN initially setup as a 20-inch .223, which was awesome. It shot very well, and even with the longer barrel it felt lighter than my shorter MDRX. But I wanted more, I wanted the 6 ARC performance. Which in my opinion felt kind of like a 5.56 that shoots like a 6.5 Creedmoor.
if you look closely you can see my advanced gas block placement
The 6mm ARC
Hornady has put out a bunch of new calibers over the past few years, and the 6mm Advanced Rifle Cartridge (ARC) is one of many. The ARC boasts a very efficient design that gives impressive performance from AR15 platformsor micro bolt-actions like my Howa Mini.
The ARC can push 105 grain bullets at near 2800 FPS, which is still doing over 2000 FPS at a quarter-mile away and still carrying over 1000 lbs of energy. For comparison, thats much faster than a good 77 grain 5.56 load, and double the energy. And at 1000 yards, the disparity is just as impressive, not that I’d like to catch either of them. The 6 ARC can be fired from the same sized actions and magazines as the 5.56, so this ballistic advantage is enticing.
My former experiences with the 6 ARC in my MDRX and Howa Mini were very impressive, both from a target shooting aspect as well as hunting big game. We’ve killed several deer and antelope using the same 105 Hornady BTHP. This led me to be even more enthusiastic about an ARC for my WLVRN. Since my MDRX is a little heavier, and I already have bigger caliber conversion kits for it like 308, 6.5CM, and 450BM, I figured I would keep the WLVRN more of a smaller caliber rifle. The added accuracy benefits of the WLVRN also seemed like a better platform for a DMR type rifle.
I started this project by contacting my long-time friend and gun-plumber at ES-Tactical. Despite his not wanting to get involved into another oddball project, he agreed to cut me a twenty-two-inch barrel from a K&P blank. It was a totally different profile than a typical WLVRN barrel, aside from a heavier profile I also spec’d a different gas block position further down the barrel.
Once I had the barrel in hand, I wanted to try something before it was even finished. I torqued down the barrel extension with some thread-locker, and headed to the range. With no gas block or piston operation, I wanted to see how accurate the barrel shot. So I fired a couple groups, operating the rifle manually like a straight-pull action. I was astonished to see that shooting my 105 grain handloads at 100 yards, the WLVRN put ten shots into just over 1/2 MOA. Something I wouldn’t have believed had I not shot it myself.
The very first shots from the clean barrel, prior to installing gas block
My reasoning was to see how much the rifle’s accuracy was effected by the gas operation once installed. Which was my next step.
Machining
It was time to make some metal chips of my own. I drilled a gas-port in the barrel and pressed the gas block down snugly. I figured I would just use the same gas-valve that my 20″ 223 barrel used and see if I could get it to work on one of the settings. But before I got that far, I would need a custom piston. Having moved the gas block towards the muzzle of the barrel, would require adjusting the length of the gas piston accordingly.
my freshly pressed gas block and custom piston
You might be asking yourself why I moved the gas block at all. The reason is to get a better purchase of the gas flow. By moving the gas block down the barrel towards the muzzle, the operation of the action is delayed slightly. This allows the bullet to exit the barrel long before any action movements, as well as allowing the gas-pressure within the barrel to decompress some. This makes ejection and extraction less stressful on both the rifle and cartridge case. There’s also an argument to made for barrel harmonics and accuracy as well. Timing the piston operation can greatly enhance accuracy by changing the way the barrel whips as the rifle reloads itself.
Once I had my custom piston ready, it was time to see how the rifle would function. This would require some trial and error, going through a variety of malfunctions tuning the gas flow until we found a happy medium. Luckily, my gas valve selection was close enough, which meant it was time to go back to the range. An unfortunate consequence in both the MDRX and the WLVRN was significant damage to cartridge cases when the rifle didn’t eject them properly.
both the WLVRN and MDRX are hard on cases when they don’t run right
First Range Trip
Accuracy
It was time for the first real range trip, with a fully functioning WLVRN. This trip was actually into the mountains and not the range, but I prefer the mountains over the range anyways. It would allow me to see how the rifle performed at distance as well.
My initial accuracy test were okay at best, mainly because I hadn’t anticipated for the weather. It was cold and snowing with some blustery wind thrown in, and to add some pressure it was getting late so I rushed it more than I’d have liked.
Even so, the WLVRN printed some barely sub MOA five shot groups. Later testing would prove even better. Most of my testing was done using a suppressor, my Anechoic Anechox 35 which made the rifle very tame and pleasant to shoot. I also shot it using the Yankee Hill Machine Turbo T3 which was better in some aspects I’ll detail below.
You can see from my additional testing, typical groups from the 6 ARC WLVRN average around 3/4 MOA. While the better groups would shrink as small as 1/2MOA. I am fairly confident this had more to do with me than it did with the WLVRN.
Long-Range
Just because I am incapable of not trying, I stretched the 6ARC out a ways to see how it did at some longer distances. We shot at 715 yards, and 430 yards in some pretty gusty wind. At 715 yards I held about 1.2 MIL into the quarter value wind and was very impressed with the impacts. Not only were they very consistent, but they really hit with some authority.
While shooting at the 430 yard-line, I aimed at a small patch of snow in some dirt. I can’t imagine the snow patch was much bigger than a can of tuna, and every shot from the WLVRN would have sent Starkist fish everywhere. I was really getting excited about this rifle’s potential.
Shooting this same load in my MDRX has proven to be very effective at distances as far as 1000 yards away. Taking varmints that far away is a fun and challenging venture, and with the same load my wife took down an antelope at just shy of 500 yards.
Because I’m a bit of a tinkerer, I figured I would also try something else. My longer piston worked fine, but I also explored another option. Using a standard length piston, and an extended op-rod (the stainless rod that goes between the bolt-carrier and piston) was another option. By adding additional length to the op-rod, I would get the same effect as the longer custom piston. But in addition it would add more weight to the reciprocating mass of the bolt carrier. This would also help buffer the operation some, which I wanted to proof out. That way I could see which of the two approaches was more effective for reliability and accuracy. Come back for more on this development later…
Gas Refinement
I have no doubt that moving the gas block further down the barrel definitely helped with the function of the rifle. It likely reduced chamber pressures during extraction, and helped counter some of the barrel movement that has made accuracy a challenge with other similar variants. It also made it impossible to adjust the gas valve without removing the handguard, but I never cared about that feature anyways. I always shoot suppressed, so I set the valve and forget it.
Note the much larger profile of the custom 6 ARC barrel, and the larger WLVRN trunnion
That said, I think the significant increase in accuracy over a factory conversion kit has as much to do with the barrel contour as it does the gas block perch. The thick barrel is much stiffer, it actually barely fits in the chassis, I had to shorten the two handguard screws to prevent them from pressing against the barrel.
I also like the additional two inches of barrel, this surely helps me get as much velocity as possible out of the 6 ARC. And still gives me the compact handling bullpups are famous for. The only downside of course is weight, the added barrel diameter and length adds a fair amount. But this too is something I don’t mind dealing with, I like the accuracy over the light weight.
Suppressor Compatibility
Much of my shooting was done with the Anechoic Anechox 35 suppressor, which worked great. But since I didn’t have quite the precise ability to drill gas-holes in the thousandths of an inch, it seemed a little more challenging to get the gas flow just right. I did find that by using a different suppressor with a little more backpressure helped get just the right amount of gas volume.
the US Optics TXH and YHM T3 made perfect companions to the WLVRN
I installed my YHM Turbo T3, which is a 5.56 suppressor. The tighter bore of the T3 added some backpressure, I assume that the traditional baffle construction of the T3 also had something to do with it as well. Disclaimer: I cannot recommend using a 5.56 suppressor on a 6mm cartridge, do so at your own risk.
That said, the addition of the T3 seemed to get me to the perfect operation for the rifle and the 6mm ARC cartridge. It greatly enhanced reliability and consistency of the operation, and it sounds great too! I think its safe to assume that any similar suppressor would have provided a similar outcome. Changing suppressors to get the optimal performance from a rifle is nothing new.
Ejection
Ejection of the 6 ARC case was predictable, the port is plenty big since it can accommodate 308 sized cases. I did switch out the polymer ejection port to the older MDRX style aluminum model, as they are a little tougher.
There is always something to learn with these projects. I for sure still like the 6mm ARC, perhaps even more so now because of my WLVRN. It has turned my little green wolverine into something quite a bit more mean. I still have the low recoil and efficiency of small cartridges, but significantly more downrange energy. Though if I did it again, I think I would have gone with a slightly lighter contour on the barrel. And probably fluted it as well, just to keep the WLVRN as light as possible. The accuracy from this combination makes the rifle more than suitable for my hunting purposes, both big game and varmints will soon succumb to the WLVRN and its 100 grain bullets in the next few weeks.
Since finishing the 6 ARC, I used it on a successful cull hunt for mule deer. This doe was taken at 300 yards shooting the Hornady 105 BTHP handloads
I’m sure I’m not the only one imagining the possibilities with this rifle; An accurate (sub-MOA) semi-auto rifle fed by 20-round magazines, with a kill envelope arguably to 1000yds, that weighs in under 11 pounds and 36.5-inches long with a suppressor…
[1000yard stare intensifies…]
That is not to say that these projects are for everyone. You absolutely must be some kind of a tinkerer, with a mechanical inclination. There is plenty of headache and challenge involved in a project like this. And theres always the possibility that your result isn’t as reliable or great as you’d hoped after spending a good amount of money. So temper your enthusiasm and expectations before considering a project like this. As always, I will update this with more information as it develops so make sure to follow me for.
The Howa Mini Action rifleoffers a compact rifle for hunting or sporting purposes, the very short action is designed to run only the shortest center-fire rifle cartridges. With the extra short action, the Mini is designed for cartridges like the .223 Remington and 300 Blackout. As well as newer cartridges like the 6mm ARC model we are looking at today. The Model 1500 Mini is a push-feed two-lug bolt action, it is fed from a detachable box-fed magazine.
2025 update, the Howa Mini 6 ARC continues to perform. My wife took this handsome little buck with a single shot, read all about it in A Stalk to Die for
Howa has long been known as a very affordable and reliable rifle manufacturer. Their products have typically been marketed toward the hunting public. But in recent years they have also moved into the precision shooting competitive world as well.
My purpose for the Mini was along the same lines, I bought the rifle for my wife who is also quite petite. She needed a good rifle that shot well for all of our shooting adventures, and the Mini fit that niche quite well.
Its lightweight and soft recoil made it the perfect choice for someone like my wife. And since I already was quite familiar with the 6mm ARC, and had a great deal of components to load it. I figured it would be a great choice. I’m excited for this fall to see just how well it functions for her on the deer and pronghorn antelope hunts that we plan to do. After having spent a short time with the rifle, I expect we are going to enjoy it very much.
Howa Mini 6mm ARC Review
When I purchased the Howa Mini, it came with the option of an included riflescope from Howa’s sister company Nikko Stirling. I figured I’d give it a try, and see how the package performed.
As I lifted the package from the box I was immediately pleased with the weight, sure it would have been even better had it weighed less. But it was certainly not heavy at 7.4 lbs for the whole package. I lifted the bolt and ran it back and forth a few times, followed by pulling the trigger. I love two-stage triggers, and to be honest I’d forgotten the Mini came with one. It felt great, though I think I might lighten up the pull weight in the future.
The synthetic stock was another surprise to me. Typically the inexpensive polymer blend stocks that come with economy grade firearms are pretty flimsy. They flex far more than you’d want them to. I was genuinely surprised by the Mini’s stock, it actually felt quite rigid. Far better than most every other comparably priced rifle stock I’ve played with in the recent past. This would hopefully translate into better accuracy for us in the field.
I looked through the little 4-12×40 scope. To my surprise it had a milling type reticle and an exposed target turret with MOA markings. It looked pretty good, and made me even more anxious to get it in the field.
The Howa Mini looks to be a perfect little rifle for someone looking for a compact and inexpensive rifle in a small caliber, but one they could use in the deer woods.
Compatible with Remington 700 two-piece scope bases
Cons
Detachable box magazine is a little weak.
First Impressions of the Howa Mini 6ARC
My first trip to the range with the Howa Mini was pretty easy going. I had a great selection of ammo from Hornady. Consisting of the match 108 ELDM, the Black 105 BTHP, and Precision Hunter 103 ELDX. I was sure one of these would shoot well in the rifle.
Upon arriving at the range I sat down with the little Howa at my bench and started stuffing cartridges into the magazine. That’s when I noticed more about the magazine design, it was a bit flimsy. I mean it works fine, and I’ve shot quite a few rounds through it without issue, but it’s awfully thin. And I feel like if I was to smack it hard into a tree-trunk or rock it would surely split apart and send my ammo all over. I also wish they made a flush magazine option that didn’t hang down out of the stock. Neither of these things are deal breakers for me, just something I’d point out.
I’d boresighted the rifle prior to arriving, so I immediately set to zeroing the rifle at the hundred yard target. In just a few shots I had a solid zero, so I fired a five shot group using the 103 ELDX load. The group measured just barely over 1 MOA, which isn’t bad but not as good as I’d hoped. Later shots would prove to group much better.
The Mini shot even better when suppressed by the Yankee Hill Machine Nitro N2.0
We then tried shooting the other two ammunition types I’d brought along. They averaged slightly smaller but not enough to matter much. Then I spent the afternoon shooting a few more targets and feeling out the rifle. I was actually quite liking the feel of the little Howa. The trigger felt great, the bolt was smooth and easy to run quickly. And despite my complaints about the magazine, it ran flawlessly. My next trip was a shooting hike into the snowy springtime Rocky Mountains. I’d brought my daughter along for company and to get her out of the house. And of course to try shooting the little Mini 6 ARC. I’d
Range Trip round Two
I’d taken the liberty of swapping out to a different scope and mounting system mainly because it was so easy to do so. After removing the Nikko Stirling scope and mounts, I dropped a two-piece Remington 700 base on the action, followed by some Warne steel rings to hold my US Optics TS25X. I felt a little bit more confident with this setup, even though it did add a little bit more weight. I felt it was a good trade up.
Again I had the rifle zeroed in just a few shots, and in no time we were smacking targets all over the mountain. For suppression I was running my Yankee Hill Machine Nitro N20 Titanium suppressor on the rifle, which made it even more pleasant to shoot.Both my daughter and I had a great deal of fun shooting the Mini. Picking out little specks of snow on the opposing side of the canyon for targets.
A typical group made from my 105 BTHP handloads
It was a great confidence builder everytime the snow would splatter leaving a dark spot in the moist mountain soil. I stretched the little rifle out as far as six-hundred and twenty yards, and it was still hammering with acceptable accuracy to hit a deer. After a few hours playing in the mountains I was very satisfied with the rifle. Knowing that we could have easily taken a deer in these same hills where we hunt every fall.
Everything about the Howa Mini fit well into my activities. The size of the rifle is perfect for doing lots of hiking. Everything worked great on the rifle, and it was very effective at putting hits on target. I feel like adding the better scope and mounting system surely helped the rifle shoot better. Though I’m quite happy with it, I may do some additional tinkering yet to see if I can squeeze any more accuracy out of it.
Reliability
The Howa Mini functioned flawlessly during my testing, no malfunctions or issues.
Accuracy
Accuracy from factory ammo wasn’t bad, whereas my handloads turned out to shoot excellent. Typical groups with handloads were 1/2 MOA. For what it is and what it costs, I am quite happy with the Howa Mini.
Overall Feel
The Mini feels better than its price point in my opinion. I’ve spent more money on rifles that didn’t feel this good. It’s comfortable to handle and functions great.
Features
Disassembled you can see the two-stage trigger
Mini Action-
The ultra-short Mini action is lighter and smaller than most rifle actions. It looks like a Model 70 that someone put in the dryer too long. This smaller action shortens the bolt-stroke, allowing you to repeat faster. The icing on the cake is the ability to use Remington 700 scope bases on the rifle.
Two-stage Trigger
I love the two-stage trigger of the Mini. After lightening up the pull weight a little bit it felt even better. It’s not a Jewel or Trigger Tech, but it feels great for a factory rifle two-stage. The safety is a three position that locks the bolt closed in the 3rd position.
Threaded barrel
Though I wasn’t a huge fan of the magazine, it wasn’t a deal breaker
Thank goodness the folks at Howa live in this century, and provide most rifles from the factory with threaded barrels. Suppressors are more popular than ever so this should be the norm. I ran my suppressor as well as a good muzzle brake on the rifle. And was quite happy with either option. Both greatly reduced recoil making it possible to spot my own impacts.
Detachable Magazine
This is the one weak spot for me on this rifle, but I’ll admit I may be looking a bit hard at it. I wasn’t surprised to see a plastic magazine and floor-plate based on the price of the rifle but I was hoping for a little bit better one. Regardless, I will happily run this mag until it falls apart, and thenbuy another for the $30 or so that they cost.
The glass filled nylon stock of the Mini felt great. Not because I like nylon stocks but because it is one of the better ones I’ve ever used. And the fact that Howa included a pillar bedding system gives them extra points. The stock was very rigid and tough.
How We Tested
With intentions of keeping this rifle, I gave it a good wringing out to ensure there was nothing I couldn’t live with. I spent a great deal of time tinkering with the rifle, even taking it apart on to see what makes it tick. I ran the bolt just like every other rifle I own, only to find out that I didn’t need to. The smooth bolt fed and extracted cartridges with ease. It has a good strong ejection pattern to get spent cases out of the way. Shooting the Howa Mini from every different position, loading and reloading it all the while was great. Shooting supported from a bipod was where it shot best but that is pretty standard. It shot all the different types of ammo I brought just fine, including my 6 ARC reloads.
As I write this I just ordered some additional varmint bullets for it. We’ll see how they shoot for varmints here this spring. With either scope and mounting system the rifle functioned great, I may end up shooting this thing myself come hunting season, provided my wife will let me.
Ammo Used
I used all ammunition from Hornady, all three of Hornady’s lines of ammunition worked great in the rifle and only made me love the ARC even more.
Score Card
Reliability (10/10) The Howa Mini worked perfectly during my testing. I see no reason to anticipate that to change.
Ergonomics (8/10) I would like a more vertical grip. But I get that this is a pretty entry level rifle so I cant expect too much.
Customization (7/10) The Mini is a bit of an anomaly so there aren’t many things that will work with it. Most unfortunately a different magazine system. It’s great that it works with Remington 700 scope bases though. There are a few aftermarket stocks and such for it, which is great.
Appearance (7/10) It’s a generally good looking little rifle, I wish there was a flush mounted magazine option. There are other camo pattern finishes available, I think I’ll end up doing a custom Cerakote job on mine.
Value (9/10) I absolutely think this is an excellent value, for the few flaws I’ve mentioned I would 100% buy this rifle again. I’m already considering another in perhaps a 6.5 Grendel, but I don’t want to get ahead of myself. The scope that comes with it is nothing fancy, but to get a rifle and scope like this for the street price as little as 550 dollars is a good deal in my opinion.
I have greatly enjoyed my time with the Howa Mini in 6 ARC. I think it fits perfectly into the niche spot I wanted it for.
It’s small and light enough for the more petite shooters in my house but still carries the accuracy needed to hunt the big game animals we hunt every fall. And I am pleased with the level of quality from the little Howa, as are both my wife and daughter.
The Howa Mini’s extra short action reduces weight and length and makes the rifle extremely easy to haul around and shoot. Whether that be for deer hunting, varmint, or predator hunting, I think the Howa Mini is a great option.
If you find yourself needing something smaller than the average rifle of the gun store rack, you should look into the Howa Mini in whatever caliber fits your fancy.
-CBM
2023 Update
We have hunted with the Howa Mini for a whole year now. Using it for hunting varmints, and mule deer. My opinion of the rifle has only improved with time, it has been very reliable and maintained its great accuracy.
My wife managed to smack a little mule deer buck with it from about 200 yards.
