New centerfire ammo from Federal features the most technologically advanced hunting bullet ever made.
By Bryce M. Towsley
The heat had passed with the sun, which helped, but as daylight slipped away, so, too, did my hopes for the animal I wanted the most - the one I'd traveled 8,000 miles to hunt. In a few minutes, it would be too dark to follow the tracks, and it would be over.
We had picked up the trail of three eland bulls shortly after lunch and had been following them all afternoon. Three times in the past several miles, we had been close, but in this thick brush, the opportunity always passed faster than I could shoot. I had practiced with my rifles before this hunt, and combined with a lot of action-shooting competition on the weekends, I was as quick on the target as I have ever been in my life. But it wasn't fast enough, and I was growing tired and frustrated.
This was hunting in its purest form, tracking through some of the thickest terrain in all of South Africa. It called on every skill as a hunter and as a shooter, skills I prided myself on, but they were not enough.
We were getting a bit desperate and starting to move too fast on the track. But with daylight heading west, we had to make something happen, so we pushed harder and harder. Suddenly, the biggest eland bull stepped into a small hole through the brush. I raised the gun, and he was gone. But another hole to the left showed his buddy, which was almost as big. I turned to him and fired. The bull lunged, hit hard, and I shot again.
I learned a long time ago that admiring any shot is folly. If the animal is still on his feet or has its head up, I keep shooting. I have seen too many "dead" animals recover and escape. Several seconds and a few shots later, I stood in awe as I touched the largest antelope in Africa. This bull was about three Twinkies short of weighing a ton, and in my opinion, that's too much critter for any .30-caliber rifle cartridge. But my .300 WSM performed just fine, even with the quick shooting required and the less than perfect shot placement that resulted. It turns out the first shot would likely have ended things without assistance, but those that followed made sure.
A great part of that is in the bullet I was using and its ability to penetrate. I was shooting Federal ammunition loaded with what is the most technologically advanced rifle hunting bullet to ever hit the market, the Barnes MRX. In a few short days in South Africa, this ammo and bullet had exhibited as wide a range of performance as I had ever witnessed from a rifle bullet.
Earlier in the hunt, I had taken an impala at more than 200 yards. Based on the wound channel, the bullet expanded very quickly and penetrated completely to exit while leaving a path of destruction in its wake. On elk-size kudu, I experienced complete penetration, even with a bullet that shattered both shoulders. Wildebeest, zebra, warthog and now this big eland all fell to this new wonder bullet, and with each one, we would spend hours in the skinning shed tracing bullet paths and evaluating the performance.
In my mind, the perfect rifle bullet will expand soon after contact, and once reaching optimum expansion diameter, will stop expanding. It will then retain its shape and weight and penetrate deeply. My preference is to have exit holes with most shots on game. That's the performance we were seeing with the MRX and Federal ammo.
While in Africa, I was able to trace the wound channels and witness the performance of 24 different 180-grain .30-caliber MRX bullets impacting game. Most exited, and I was starting to think we would not capture any bullets until I shot a zebra. For those who don't know, zebra can be very difficult to hunt, as they are smart and spooky. They are also extremely tough and sometimes shrug off good hits with little immediate visible effect. The shot was about 250 yards, as the zebra was quartering away. The recovered bullet entered behind the ribs, broke the off shoulder and was recovered under the hide. It lost one petal but retained the other three. It weighs 168.1 grains and is expanded to .640 inch at the widest point. Measuring from the missing petal, it measures .510 inch.
The eland provided the only other recovered bullets. I put seven bullets into the bull and recovered only two. (I wanted to recover some bullets, so I continued shooting.) The finishing shot was from just 15 yards, and the bullet hit the point of the shoulder. After shattering that massive bone, the MRX was recovered inside the chest cavity. The petals are missing, but the shank is intact. It weighs 127.2 grains and measures .410 inch.
Another bullet hit and shattered the massive hip socket of the bull and was found in the stomach. The bullet lost two petals and weighs 165.4 grains. It's beat up and hard to measure, but it's .590 inch at the widest point.
These are shots that would have taxed even a dangerous game stopping rifle with much larger bullets. An animal this big has a huge bone structure, and I believe almost any other .30-caliber hunting bullet would have self-destructed when impacting these huge bones at nearly 3,000 fps.
I even put a few of the MRX bullets into the shoulder and leg bone of an elephant I took in Zimbabwe the following week. This, of course, was after the bull was dead and was only to test the bullets. They shattered the massive bones and continued to penetrate into the chest. We were not able to recover the bullets, but we also did not find any pieces indicating they broke up.
In 2003, Barnes advanced the technology of their famous X-Bullet to new levels with the introduction of the Triple Shock X-Bullet. The result was less bore fouling and accuracy that often rivals target bullets. The addition of a polymer tip was the next logical step. A polymer tip has a sharp leading edge profile, will raise the ballistic coefficient for flatter trajectory and more downrange energy and will also help to initiate expansion. High ballistic coefficient and low impact velocity expansion are both important for long-range shooting, particularly at relatively small animals like deer or antelope. However, because the specific gravity for copper is 8.93 compared to 11.34 for lead, a bullet of equal weight and made out of pure copper will be significantly longer than a lead-core bullet. Adding a plastic tip would make the all-copper Triple Shock bullet too long to fit in the magazine of a lot of rifles without the bullet being seated too deep in the case.
Barnes and Federal teamed up to solve the problem using some very cutting-edge technology. They developed powdered-metal technology that is new to the bullet-making industry to create a tungsten-alloy core for the bullets. This heavy and dense core is inserted into the base of a shortened Triple Shock bullet to boost the weight-to-length ratio. This also moves the mass of the bullet to the rear to aid in penetration of the expanded bullet.
The result is a bullet that is significantly shorter than an equal-weight Triple Shock. For example, with the addition of a 62-grain core in a .30-caliber 180-grain bullet, the length of the copper bullet is reduced by 3/16 inch. Barnes utilized this length reduction by adding a Delrin (polymer) tip. The result is a bullet that is the same length as the Triple Shock, but with a polymer tip. Coincidently, this bullet is about the same length or shorter than some of the new lead-core polymer-tip bonded bullets.
Polymer tips add aerodynamic advantage, and the new bullet has a ballistic coefficient increase of 10 percent over the Triple Shock, which is already a high-BC bullet design. The polymer tip is inserted deep into the hollow cavity of the bullet, and on impact, it acts like a wedge to initiate the expansion process. When combined with some changes in the bullet design, this has lowered the impact-velocity window for expansion by an average of 200 fps.
Penetration is exceptional with the X-Bullet nose design because of the four distinct petals that are formed when the bullet expands. These four petals do several things. First, the surface area is less than a conventional lead core bullet expanded to the same diameter, so there is less resistance. Also, the gap between the petals acts as a ìrelief valveî to allow tissue to flow between the petals rather than being pushed forward or to the side as with a conventional bullet. Finally, the petals are formed with sharp edges so that they cut as they penetrate.
After returning from Africa, I traveled to the Federal factory in Minnesota and then to the Barnes factory in Utah to test the bullet further in their laboratories. (This was a bit delayed, as I was stranded in Zimbabwe for a while by a strike at South Africa Airlines.)
Our first test used a .30-caliber 180-grain bullet with a muzzle velocity of 3,037 fps fired into clear ballistic gelatin positioned at 200 yards. The measured ballistic coefficient for the Barnes-tipped bullet was .443, and impact velocity was 2,633 fps. One typical recovered MRX bullet that I measured had expanded to .630 inch, weighed 178.9 grains and penetrated 33 inches of gelatin. (Expansion is measured at two points, using each of the four petals and then averaged.)
We added a cow's femur bone imbedded in a 12-inch ballistic gelatin block, 1 inch from the face. That block was backed up by two more 12-inch gelatin blocks. The Barnes bullet performed perfectly after striking the bone with a 2,706 fps muzzle velocity and impact at 15 yards. That is to say it retained weight, kept its petals and shape, and it penetrated 28 inches. I weighed a typical bullet from this test, and it was 177.8 grains. Expansion was .630 inch.
When impact velocity is pushed to 3,000 fps, things change with most bullets when testing with this type of large and tough bone. The first MRX bullet we tested had a muzzle velocity of 2,974 fps. With a 15-yard impact, it penetrated and shattered the bone and scattered its petals in the next 10 inches of gelatin. The remaining shank weighed 128.4 grains and had a nose diameter of .380 inch. After shattering the bone, it penetrated the full 36 inches of gelatin and exited. It hit the Kevlar backing, pushing the heavy wooden block behind it a few inches, before stopping. Actually, this is very good performance for a big game bullet and is what is expected with an impact on large bone. In several 3,000-fps impact tests with bones, the majority of the bullets passed through the bones and continued to penetrate. Some penetrated the full 36 inches of gelatin and exited.
These were prototype bullets, and in the months that have passed, Barnes has improved on this outstanding performance. Tim Janzen from Barnes told me that with a little tweaking, they now have a bullet that they cannot make fail in gelatin and hard barrier tests using available hunting cartridges, failure being defined as a jacket and core separation.
Two points that are important here are that, first, using cow bones at high velocity is an extreme bullet test and might well be the most demanding of any the industry uses for hunting bullets. It simulates a worst-case scenario that is almost never encountered in the hunting field. Second, they have subjected all the other popular premium hunting bullets on the market to the same test, and no other bullet retains weight and bullet integrity and continues to penetrate as well as the new Barnes MRX. Most bullets fail this test at a much lower velocity.
The .30-caliber 180-grain bullets must expand reliably at 1,800 fps in water to be accepted. The upper end for staying intact and penetrating in gelatin has not been established because no current rifle cartridge can drive it fast enough to fail in gelatin. The MRX bullet is exhibiting what is probably the widest performance spectrum of any hunting bullet on the market. Combine that with an extremely high ballistic coefficient and good accuracy, and I think this may well be the ultimate do-anything big game rifle bullet.
In South Africa, the author hunted with Leon and Mandie Myers of Matla Mamba Safaris, and says it's one of the best hunting operations he's ever visited. For more information, call +27 (14) 754-4453 or visit www.matlamamba.co.za.
Reprinted from the July 2006 issue of Buckmasters GunHunter Magazine. Subscribe today to have GunHunter delivered to your home.