Category Archives: Shooting hardware

Rifles and their parts

Suppressed Weapon Systems MISB 308Win for the SRS

I swore off shooting unsuppressed long ago, and I only do it occasionally by choice. The suppressor bug bit me hard many years ago, and I have never vanquished its effects. With that in mind, I am always thinking about better ways to hush the noise of my favorite pastime. Who would have thought that an idea I had depreciated would turn my jaded eye.

One of my most favorite rifles of all time, is my old Desert Tech SRS A1. I have run countless barrels through it, I currently have somewhere between ten and fifteen barrels of assorted different calibers. Factory, custom, and even a few specialty barrels. Even with all those options, I still love my old 16” 308 Winchester Covert barrel. The calm and consistent performance of the 308 is like an old friend, so when I got the opportunity to try yet another great 308 Winchester option for my favorite rifle, I jumped at it.

Suppressed Weapon Systems has been in the suppression business for some time. They specialize in the integration of suppression technology directly into the firearm, instead of making the suppressor just a muzzle device. Their MISB (Monolithic Integrally Suppressed Barrel) is available for many different firearms, including my dearest SRS. The modularity of the SRS family of rifles makes it ideal to pair with technology like the MISB, and with a durable cartridge like the 308, it would last for some time.

I’ve often tinkered with the idea of an integrally suppressed barrel for my SRS, but I was always worried about spending the money on an NFA item that would get burnt out and need to be replaced. A valid concern I had always thought, but the MISB is constructed in such a way that the tube can easily be removed and installed on a new barrel/baffle stack. So with my main concern assuaged, I dove in with both feet.

The Suppressed Weapon Systems MISB for the SRS is manufactured from a Bartlein Barrel blank, well know for great quality and precise shooting. The muzzle is cut at a determined length, in my barrel’s case, around sixteen inches. But the remainder of the barrel blank is then cut into the suppressor baffles. The length of the barrel to the breach of the muzzle is fluted, and drilled, I assume to decrease weight but also to add an expansion chamber for venting high pressure gas.

The outer tube of the MISB is a good fit, but not entirely tight, this was a bit of a concern for me at first but I later learned it was necessary to free-float the barrel. Having the outer tube captured and tightened with the barrel would add stress and torque to the overall structure. The tube is sealed at both ends with what appears to be Viton high temp fluoroelastomer O-rings. The muzzle end of the MISB has a threaded cap also sealed with the O-ring, it is knurled and has cuts for torquing it into place with a tool. Its an impressive example of machining design and ingenuity.

I couldn’t wait to get the barrel mounted in my rifle chassis, and test its performance. As soon as I got home with it, I hurried to my basement man-cave and installed it into my SRS. I found the fit to be a bit snug, perhaps more-so than any other barrel I’ve tried. Its easy to get a burr on the shank of SRS barrels, one must be careful. But that was not the case with the MISB, it was simply just a bit tight. Perhaps a slightly smaller diameter would help, but I found it to be consistent, so it was a minor inconvenience. It was the same when I mounted it in my SRS A2.

Once mounted, I headed for the hills to get the rifle zeroed with this new barrel. As usual, it was an easy process. Most SRS chassis will change POI with a different barrel, but it is rarely off by more than a few inches. So a quick re-zero on my scope was easy, and in no time I was using the rifle to shoot steel at 710 yards.
SWS guarantees sub MOA accuracy for three shots with their MISB system, but suggests that 1/2 to 3/4 MOA is expected more often than not. I found my barrel to be consistent with that.

The suppression quality of the barrel was on par with what I expected. The first round pop was significant, but quickly forgotten with successive shots. The slender barrel looks very handsome in my A1 with the longer handguard. A few inches longer than a standard twenty-two inch barrel which pokes just out of the handguard. When mounted in my Covert A2, it was a few inches longer than the standard Covert sixteen-inch barrel when fitted with the DTSS Suppressor.

Conclusion
I think the SWS barrel offers a great option for those looking for a slender and inconspicuous barrel to keep things quiet. At $2200 for a barrel, it is no small investment. But it’s also not much different than a good barrel fitted with a suppressor would cost you, and SRS owners are gluttons for dropping coin on good barrels. And the fact that you can reuse the tube on a new barrel blank having no interaction with the Federal agency everyone loves to hate makes it even more appealing. I look forward to using it even more in the future.
-CBM

The 257 Blackjack

You may have read my piece on the 25 Creedmoor from a while back, if you haven’t then make sure you go read it after this. In that article about the 25 Creedmoor, I detailed how my nascency in precision rifle shooting began with a twenty-five caliber rifle, and that I had returned again to the quarter-bore. There’s more to that story, however.
One of the main reasons I quit shooting that old twenty-five 0’six, was because there was never a good bullet selection for it. The biggest bullets available were one hundred twenty grain, and they were hardly long-range bullets, with ballistic coefficients not much better than anything else designed in the sixties. That was all about to change, and change for the better. I couldn’t have known how far down the quarter-bore hole I was going to fall when I first made contact with Blackjack Bullets.

The 257 Blackjack next to its larger parent, the 6.5 SAUM

That first conversation I had was with Miles Johnson, the brains behind Blackjack Bullets. Like me he had often hungered for a better bullet for twenty-five caliber cartridges, but he had the intellect and drive to do something about it. Miles is a smooth-talking guy, with very unequivocal purpose in conversation. The kind of guy you could sit around a fire with a bottle of whiskey and watch the stars, and before you know it he might be talking so deep about drag and aerodynamics that you have to start reading the bottle to find words you understand.
Our initial contact began my twenty-five Creedmoor project, Miles’ company Blackjack Bullets was producing the 131 Grain Ace bullet, and I intended to make it the crown jewel of the project. Which has been an extremely superior performer for me lo these short two years, it leaves its six-point-five cousin in the dust. But Blackjack had been working all along on something even more threatening and treacherous, it was their own cartridge that was purpose-designed to make the 131 Ace sing a tune that nobody could touch. That project was the Two-fifty-seven Blackjack, a short action magnum cartridge based on the SAUM case. It would fit in short action rifles, feed from AI patterned magazines, and push the Ace beyond thirty-two-hundred feet per second. It falls somewhere between the old 25WSSM and the 25SAUM wildcat.

The 131 Ace has an advertised G7 BC of .330, my personal experience and testing led me to believe that number is a tad conservative and that the number is more like .340. With an immaculate profile like that, the Ace when launched at these speeds is as flat as most available cartridges you can get, and it cheats the wind from its deviant influence.
Since the twenty-five Creedmoor had been such an outstanding success, I decided that I must indeed have the two-fifty-seven Blackjack as well, I figured it would be an amazing Rocky Mountain hunting rifle. So as soon as Miles had a reamer, we got started on the project.

The Pit Boss. Sporting a 24 inch Proof Research carbon wrapped barrel, and a YHM suppressor adorns the muzzle.

With weight in mind, I decided I would spend the extra cheddar and get a Proof Research carbon fiber barrel with a 7.5 twist. My 25 Creedmoor is a 7 twist, but with the much faster Blackjack I needed a slightly less agressive twist. It was matched to a lightweight carbon fiber stock from Iota Outdoors. Both would be connected with a simple Remington 700 short action. I swapped the factory trigger for a superior one from Trigger Tech, this has been a pretty standard practice for me. On top I mounted my US Optics TS 20X, which I think is perfect comapnion for this lightweight but long range hunting rifle. That said, I have a USO Foundation 3.2-17 on the way that might go for a ride on the Blackjack as well.

Trigger and magwell detail, all a perfect fit.

Next, it was time to start load development. Which requires making brass from something else, the easiest seemed to be Hornady 6.5 4S cases, they were cut, sized, annealed, then cut again, sized again, turned, and annealed. The finished product is a beautiful fat and short little case, it looks like the X47 after an all you can eat 24 hr buffet.
Mine is only the third rifle chambered in the Two-Fifty-Seven Blackjack so load data was based entirely from what Blackjack bullets had tried in theirs. I tried several different powders, including H4350, H4831SC, but I ended up getting the best velocity with Alliant RL 26. With 56 grains of powder, I was getting just shy of 3300 feet per second. Fireforming these fat little cases gave some slight variation in velocity, but that didn’t surprise me. I did quite a bit of testing with loads back and forth, which is a tedious process with such a limited supply of brass in which I was so heavily invested. Magnum primers seemed to give the cartridge too much of a pressure spike, and excessive wear to the cases, so I backed down to just a Large Rifle primer, which significantly softened the blow. This change still gave me adequate velocity, but also saved my brass from being ruined prematurely, and eased in extraction from the chamber. The Ace likes to run right around 3200FPS from the Blackjack, and that’s just fine with me.

A typical group from the 257 Blackjack, including a true coldbore shot (left) and four followup shots.

With no shortage of space here in the Rockies, I decided to get the Blackjack out to some significant ranges. I wanted to see how well my projections panned out, and see how close the trajectory lined up with my ballistic computer Trasol. My first distance conquered was 1025, this after confirming a fairly rough zero in the dirt at 150 yards. From there I dialed the indicated 5.3 MRAD, and closed the bolt. One of my favorite things about shooting that far, is the nice delay you have to get a good clear sight picture to watch the impact. The first impact was a touch low, so I corrected the .2 and fired again, making perfect elevation on impact. I then shot it at 1250 yards where it was slightly ahead of the predicted dope, and I had to dial back down half a MIl to get on target. I then stretched it out to just a few hundred feet shy of a mile, and 12.8 MRAD was just the ticket for that range. For the naysayers, that is two MIL’s ahead of the 220 grain 300 RUM I was testing a few months back. And at 1600 yards, the Blackjack is 300FPS faster than the RUM, and only 60 pounds of energy less than the RUM. These are of course estimations made by my ballistic calculator, but they appear to be spot on based on the data I’ve shot to within a reasonable margin of error.

Shooting these 25 caliber heaters through this carbon wrapped barrel can heat it up quick. This rifle was purpose-built to be a hunting rifle, so barrel heat is of little concern. Rare is the occasion that I shoot more than a couple shots, so the weight savings are far more valuable to me in a hunting rifle.

The recoil on the Blackjack is not bad at all, but for a short action I would call it sharp. Obviously, there is going to be some kick from something this spicy, but its certainly not bad, I would compare it to a heavy 308 load, keeping in mind the eleven-pound rifle weight.

One of the many concerns I am hearing from people about this project is the old “barrel burner” comment.
Yep, its gonna get roasted. If it gets to 1200 rounds I’ll consider myself lucky, and then I’ll get another barrel cut and threaded and screw it on in too. That is if I haven’t found something even sharper than the Blackjack by then.
Another concern I have heard from many is about feeding. Short and fat cartridges tend to have feeding issues, especially with steep shoulders like the Blackjack. But to my gratification, I have yet to have a single malfunction. It smoothly feeds from an old beater AICS magazine, which will hold seven of these handsome dandies. Whether the first, or last round from the mag, these hop right into the chamber without any hangups. And single feeding is no problem either, if you just toss them in with a bit of forward motion, so they clear the blunt breach of the barrel, the bolt closes smoothly.

Bolt knob detail. The 257 Blackjack was initially to be called the 257 Pit Boss, I decided to honor the original name by memorializing it here.

A wildcat cartridge is an adventure wrapped in hundred dollar bills, but it is not without its fun and excitement. I am not even close to being done with the 257 Blackjack, hunting season is just around the corner, and I fully intend on putting the Blackjack’s talents to work. With both deer and elk to harvest this fall and winter, the downrange energy, and resistance to wind, this lightweight but potent little rifle is a perfect candidate for these rugged Rocky Mountains that have become my winter range. With any luck, brass will be commercially available within the next few months from at least one reputable manufacturer. Reamers and dies will also soon be available from Blackjack Bullets website, so it may not be too long before this little cartridge is made an honest one.

In the meantime, I will continue to prepare and practice for the hunting season waiting for the next best thing. Miles may have some mad scientist things going on at the Blackjack Lab somewhere in the hills of Oklahoma. The best news of all perhaps is that big names like Berger and Hornady are following the lead, coming out with better bullets for the quarter bore fans like myself. So the future of the 257 Blackjack, as well as my 25 Creedmoor, and any fast twist 25 caliber cartridge will be bright and long-lived.

-CBM

The Desert Tech MDRX

Advancing technologies have made every part of the firearm and shooting industry better, with new materials, better production equipment, and a growing competitive market all driving forward it is no wonder that so many new and exciting products are available today. Desert Tech has been pushing those limits since its inception in 2007, and this year they have released another great product that follows the Desert Tech adage Tomorrow’s Weapons.

The MDRX is the next generation rifle from Desert Tech, it builds on the already popular MDR rifle they released in 2016. The MDRX is a short-stroke piston operated semi-automatic bullpup, for those who don’t know already, a bullpup is a rifle configured such that the action, magazine, and firing mechanics are all located behind the trigger. The purpose of this design gives the MDRX a shorter overall length than conventional rifles of the same barrel length. When you add in the other additional features of the MDRX the difference becomes even more apparent.

Features
All Desert Tech rifles are designed with modularity in mind, and as such, they are all available as multi-caliber chassis and barrel combinations. The MDRX shares that same heritage, as it stands at the moment it is available in four different calibers from the factory; 223 Wylde, 308 Win, 300 BLK, and 6.5CM. All four of these barrel conversion kits can be interchanged in the same chassis, making the MDRX one of the few modern sporting rifles to accept both large and small frame calibers. All this from an SBR sized weapon without the stamp.
Being a semi-auto bullpup adds some challenges when it comes to universality, these challenges were overcome with ingenuity. The MDRX is completely ambidextrous, all of its controls are mirrored on both sides of the rifle for both right and left-handed shooters. In addition to the ambi controls, the rifle has a forward ejecting system that sends spent brass casing forward away from the shooter. Previous bullpup designs eject brass to the right side, which in a bullpup is a bad thing if you are left-handed. The MDRX can be fired from the right or left side with no concern of catching hot brass to your face. And if you are a dedicated left-hand shooter, you can swap ejection from forward right to forward left in just a few seconds.
The MDRX comes standard with a compensator made by Desert Tech called The Ratchet, the compensators are caliber specific to provide the best performance in recoil reduction and to stop muzzle rise.
One of the major challenges with bullpups is creating a good clean trigger pull, this is due to the linkage required to connect trigger shoe to the sear pack. This is another challenge that was overcome with design ingenuity, and the resulting trigger feel of the MDRX is widely accepted as great. Of the many people who have pulled the trigger on an MDRX, the common consensus is that it is a good trigger, not just for a bullpup, but a good trigger period.
The MDRX has a six-position adjustable gas valve allowing the operator to tune the rifle to whatever ammunition they might use, as well as use the rifle with a suppressor and a lower gas setting.
The MDRX’s aluminum/polymer chassis construction features full-length upper Picatinny rail, M-LOK slots for accessories and flush-mounted QD sling cups on the rear of the receiver. It is also designed to accept most AR-15 style magazines, and for large frame calibers, it uses SR-25 pattern mags. The rifle ships with caliber appropriate P-mags from Magpul.
The various caliber conversions for the MDRX feature popular twist rates, and standard barrel thread for adding muzzle accouterments. There are also both sixteen-inch, and twenty-inch barrels available in several of the assorted calibers, giving shooters different performance options. And with different barrel lengths, there are two different handguard lengths to go along.
The ambidextrous charging handles of the MDRX are non-reciprocating, they are normally locked to the front in a spring-loaded detent. They can also be locked to the rear by pulling them back and up, the release is as simple as slapping either of the handles down, and the bolt carrier closes into battery. The gun locks open upon firing the last shot from the magazine, the bolt release is centrally located right behind the magwell. This allows for very quick reloads by simply extending the thumb when seating a fresh magazine, thus closing the bolt on a fresh round. This actually can make reloading faster than most AR-style rifles due to fewer steps in the reload process.
The forward ejection system is perhaps the most curious of all the MDRX’s features. The open-faced bolt extracts the spent case and carries it to the rear, as the carrier travels it engages the ejector with a dovetail lug on either side. The momentum of the carrier then pulls the scissor-like ejector out, and it swipes across the open bolt face pushing the spent case off and into the ejection chute opposite. There it is retained by a spring-loaded pawl until the bolt carrier again travels forward where a protruding lug pushes the spent case forward and out the ejection chute. It’s a very interesting system, the only flaw I found with it is that when unloading an unspent cartridge from the rifle, it does require a firm stroke of the charging handles to get the cartridge seated firmly in the ejection chute. This is not so much a flaw as much as it is a training practice needed to be followed. The ejection system is designed to be used on either side of the rifle, both the ejector and chute can be swapped from one side to the other in seconds.

The MDRX SE utilizes a standard side ejection system

Also new for 2020 is a new side ejecting MDRX, for those who prefer a simpler, more traditional ejection pattern. The side eject is available in. 223 Wylde only, and can also be swapped from right to left side ejection. There is also the added benefit of a lighter overall weight, and a less expensive price tag.

On the Range
With several barrels in hand, I took the MDRX into my mountain hide to test its function. I started out shooting with the sixteen-inch 308 Win barrel, and loaded with Fiocchi 150 Grain FMJ ammunition at one hundred yards. After zeroing the sights, I fired a few five-shot groups, which ended up being around two MOA in size.
I continued firing the rifle at several additional targets to see how it ran. I found the recoil to be much softer than the previous similar rifles I had shot, this surely had much to do with the Ratchet compensator. The trigger was very clean and crisp, the reset is quite audible, I attribute that to the highly conductive poly receiver who’s hollow construction makes a very resonant chamber. I fired several additional groups using additional ammunition types as well, American Eagle XM80 as well as some 168 Grain match ammo from both Hornady and Federal. The match grade ammo certainly provided better groups, they averaged right around one MOA.

The MDRX seen with 20 inch 6.5CM barrel and longer handguard

So with several hundred rounds through the rifle, and a respectable shooting and zeroed rifle, I figured it was time to test the metamorphosis of this multi-caliber gifted rifle. The barrel is removed from the MDRX using a five-millimeter hex wrench, the rifle comes with one, but I prefer to use the suggested eighty-inch-pound torque limiter. After removing the handguard via two loosened screws and one take-down pin, the barrel is released by loosening the two barrel clamp screws by about one turn, and then disengaging the barrel lock 180 degrees to allow the barrel to slide out the front of the chassis. The bolt must be locked open to the rear to complete this operation. I then installed the twenty-inch 6.5 Creedmoor barrel, seating it firmly towards the breach. The process is then reversed, turning the barrel lock 180 degrees, and then torquing the two barrel clamp screws to 80 inch-pounds with a torque limiter. Followed by re-installing the handguard, which I had swapped out for the longer one. The rifle had just transformed from a sixteen-inch 308 Winchester into a twenty-inch 6.5 Creedmoor, and I was excited to see the increased performance. The point of impact would not be the same from one barrel to the next, but it was on paper at one-hundred yards, so it only took some minor corrections.
The 6.5 Creedmoor shot very well, with 140 Grain ammunition from both Hornady and Desert Tech, the groups averaged much better, in the sub to half MOA realm. With this kind of accuracy, I couldn’t wait to take the MDRX out to more significant distances.

For several hours the rifle neatly piled up brass right in front of my shooting mat, the rifle never malfunctioned, and just kept eating magazine after magazine of ammunition. I also fired some S&B 140 grain ammo through the rifle without any problems, I would have liked to try some lighter loads like a 120 grain, but I didn’t get the chance.

A typical 5 shot group from the MDRX 223 Wylde 40 Grain Fiocchi (100 Yards)

The rifle is easily swapped to smaller caliber barrels as well, the 223 Wylde and 300 Blackout do require a little more though.
A change of the bolt, a magwell spacer, and a swap of the ejection chute are required in addition to the barrel change.
The 223 Wylde shot just as good as the 6.5 Creedmoor, sub MOA groups were easy when shooting good ammo.

The great performance of the MDRX was hard to deny, it is a very compact rifle, with incredible reach, and good accuracy. Desert Tech has upped the game with this rifle, and they stand behind all their rifles with a lifetime warranty. It would be a great rifle whether you are hiding in a tree stand, need a behind the seat truck gun, or anywhere you’d need heavy firepower in a compact package. Its larger calibers are certainly useful for big game hunting and some distant shooting, while the smaller calibers are great for quick target shooting in a 3-gun style competition or varmint hunting. The MDRX carries a higher than average price tag, but that is because it brings so much more to the table. The multicaliber option alone actually saves money by consolidating your training, and less money spent on optics and accessories. You literally could do almost every American shooting activity with this one rifle. Whether it is a home defense rifle or a suppressed ranch rifle, the MDRX is a do-all rifle if ever there was one.

-CBM

A 350 Legend for the MDR

Have you ever thought that maybe there is such a thing as too many guns? or too many barrels in some of our cases? Well if you did, you’re in the wrong place my friend. With so many terrible things going on in the world today, I like to embrace every new opportunity to shoot something. And since I have a good friend who is part mad-scientist part gunsmith, I get the opportunity almost as often as most see Bloomberg for president ads.
Watch the video at the end of this article
Once again Eric at ES Tactical has made me another barrel for my Desert Tech MDR, and this one is chambered in the new cartridge from Winchester, the 350 Legend.

The MDR with its barrel and optic collection is a do everything rifle

I’m no ballistician, nor does Winchester give me any kind of compensation, so I’ll just use their words and description of the 350 Legend. The Legend was specifically built as a hunting cartridge, a straight-walled hunting cartridge with a specific reason. Some state agencies only allow straight-walled cartridges for hunting big game, I assume this is because of the dangers of shooting beyond your line of sight in a semi-populous area. Winchester markets the Legend as the fastest straight-walled cartridge available, there are several factory loads with muzzle velocities over 2400 feet per second. They claim this gives the 350 Legend more speed than a 450 Bushmaster, more penetration than a 243, all while carrying more energy than common rounds like the 30-30 or 223.

350 Legend cartridges featuring Winchester’s 145 grain FMJ

Now that I’ve given the Winchester speech, I’ll tell you about the MDR conversion kit from ES Tactical. The multi-caliber MDR (or MDRX is the new model) is easily changed from one caliber to the next, the 350 Legend is the latest option from ES Tactical. The Legend uses the 223 Remington bolt, and magwell, but it has a Legend specific magazine due to its straight-walled design. The barrel I received from ES Tactical is eighteen inches long, it was threaded 5/8-24 to fit my suppressor, and fluted to save weight and impress the ladies. The barrel drops into my MDR chassis like any other, and after a quick gas valve adjustment, it was running smoothly.
I fired a couple different loads from both Winchester and Federal. The Winchester white box was their 145 grain fmj, while it shot just fine, it failed to impress me as far as accuracy and function. It even popped one primer out of a case which made me suspicious. The Federal Premium 180 grain Power Shock performed much better, both for function as well as accuracy. The 350 Legend was everything a deer hunter would need inside the suggested 250 yards it is recommended for, I found hitting jug sized targets boringly easy from the standing position, even at the 250-yard line. This may in part be due to the MDR’s bullpup balance, and the quality of barrel and trigger.

The 18 inch 350 Legend barrel outside the MDR chassis

For those who are still in the dark about the MDR(X), you really should do yourself a favor and check it out, it is multi-caliber, completely ambidextrous, and its bullpup configuration gives it an extremely compact chassis while carrying big options for both distance and accuracy. If your interested, you can read more about it here or there.
The 350 Legend does not like the 223 Remington ejection chute on the MDR, though they share the same case head, the lack of a bottleneck on the Legend causes a bind in the chute causing jams. The 308 sized chute won’t hold the case, so it’s no-go as well. That’s fine, just as with my 450 Bushmaster, I leave the chute off and let it throw the spent cases to the side. I did pay close attention to where they were landing though, as I intend on reloading them, and the MDR throws them pretty far.

Both the 450BM and the 350L would be great for those of you who are forced by government caveat to hunt with them, for me, I guess it would depend on whether I wanted to hunt supersonic or subsonic. Either way, I don’t think you could go wrong.

-CBM

450 Bushmaster, Slow and Steady Wins the Race

If I had a rifle for every time I fell in love with an idea, the world would lay quietly in a torpid slumber beneath a blanket of heaped weapons strewn beyond the horizon. I was blessed with a vivid imagination since childhood. My mind is in a perpetual cycle of finding project ideas, digesting them mentally until my brain has either built the whole thing and tested its flaws, or until the same has been exhausted to the smoldering dumpster where ideas die. If it weren’t for the occasional successful brainstorm that ends with a nifty new project, I might lose my mind. This is a story about one of those.

450 Bushmaster cartridges loaded with Hornady 350 grain round nose bullets, these bullets were .458 until I swedged them down to .452 for the Bushmaster

I have long wished for a slow and heavy cartridge that could readily be used for subsonic launching of big, heavy bullets that will go a very long distance. There were many possible suspects; big bore cartridges, the Whisper family, and many others. I had long wished for a 510 Whisper, but my suppressor inventory ventured only to the .46 mark. Making the 510 and similar cartridges inapplicable. The next best thing for a diet of heavy and slow would then be something in the .45 realm.
But even then, .451 or .458? Why not both?

The .458 bore has a much larger and heavier selection of bullets, and they are easily swaged down to .451. Which makes a perfect fit for the 450 Bushmaster. The 450 enjoys quality brass from Hornady, making reloading a snap. And using mild charges for subsonic velocities would keep the brass life high. The straight walls of the cartridge would hopefully last to be reloaded again and again.
The beauty of my main rifle, the Desert Tech SRS A1 Covert, is its multi-caliber role. I have a pile of barrels accumulating for it in my safe, so starting this 450 project was as simple as a barrel, some dies, and some powder and bullets.
The sixteen and a half-inch barrel was made by ES Tactical, crowned and threaded for my SilencerCo Hybrid. It didn’t take long to start falling in love with this basically large pistol.
I found that the factory Hornady Black 450 Bushmaster ammunition was a good place to start. At 100 yards it was printing groups just under two inches, I was hoping for better so I tried my hand at reloading. A set of dies for the BM isn’t as easy to come by as other calibers, all I could find were Hornady and another set from Lee Precision. I opted for the Lee set, which I still don’t regret. The four die set has allowed me to load quite a bit of very precise ammunition.

Seeing as how my objective was to eventually reach a heavy subsonic load, I went ahead and ordered Lee’s .458 to .451 swage die. That way I could take advantage of the larger and heavier selection of bullets in the 458 family. I wasted no time in doing so, some of the first reloads I tried were Hornady 350 grain round nose bullets swaged down to 451. They did pretty well, but I wanted bigger, so I purchased a box of 405-grain lead bullets that had been made for the 45-70. The lead slipped easily through my swage die, and in no time they were 451’s.

Subsonic loads for the Bushmaster used 405-grain lead solids, these were made to shoot in the 45-70, but after running them through the Lee sizing die, they ran perfectly through my Bushmaster

I tried a couple different powders, but as usual, when it comes to subsonic shooting, IMR Trailboss powder was the ticket I needed. I was blown away with the consistency of the results, I was seeing velocities more consistent than anything I had loaded prior. Not only single digits but SD numbers in the 1-4 fps range. I was praying that this would translate into extremely accurate ammunition, it wasn’t bad but not as good as I’d hoped. Accuracy still averaged around 1-1.5 MOA at 100 yards, good enough to hit most targets of mine at the ranges we expected.

My excitement about this whole Bushmaster project was tripled when Mad Scientist/Gunsmith Eric Smith built me a second barrel, this time for my Desert Tech MDR. The MDR is a semi-automatic bullpup, it brings accuracy and multi-caliber universality to a compact and quality package. I couldn’t wait to try my same loads in the MDR, I figured it likely wouldn’t cycle the action but I wanted to try anyway.

The accuracy was almost the same from the MDR as from my SRS A1, but as I feared it would only cycle the faster supersonic ammunition. I am currently working on an alteration to make it cycle, if it works out, it may be the coolest thing ever.

The goal, of course, was to use this project for some very quiet hunting. Sneaking into bow range of animals is exciting enough, but the ability for movie quiet rifle shots with one MOA accuracy made it even more exciting.

This past season we were able to put it into use, and the results were exactly as I had hoped. We had eyes on a small group of mule deer that we could predict movements with some regularity, so a good hide was fashioned that would give a view of them with no more than 120 or so yards max range. As it turns out, a young buck made his way across the opening one dusky evening, and he wandered around the 60-yard line.
The hushed report of the Bushmaster made every ear in the group perk up, but only one of them jumped. He jumped from the impact of the bullet, which hit him right above his right elbow, and passed through him exiting almost exactly opposite. He ran for about 20 yards where he toppled over and kicked on the ground for a short time.

This young buck hoped to escape from the Bushmaster, but a perfect shot through both lungs shortened his run to a 20-yard dash before he toppled

Internal inspection of the buck showed perfect damage to his lungs, the bullet passed through both lungs rupturing many vital passages along the way. His lungs quickly filled with blood, causing what most of us would call a near-perfect kill. Another positive result was very minimal meat damage, the lower velocity didn’t seem to cause all the bloody mess that supersonic bullets tend to do. It was more reminiscent of an arrow wound.

With experiences like this and all the other advantages that it brings, this will likely not be the last time we use the 450 Bushmaster for a hunt. While the purpose I have described here today may not be orthodox, it shows you what can be done with a little imagination and firepower.

-CBM