Hornadys New SST Bullets Advance In-Line Technology
by Toby Bridges
Mention saboted muzzleloaded hunting projectiles around any muzzleloading hunter and it's a darn good bet that images of a big ol' jacketed hollowpoint pistol bullet will immediately come to their mind. Well, that's not entirely the case any more.
Over the past couple of years, a few bullet makers have realized that to fully tap the accuracy, range and knockdown power of today's advanced in-line ignition muzzleloading rifles would require a bullet of the same advanced technology. It would take something other than a jacketed hollowpoint handgun bullet that was designed to be shot at 1,000 to 1,500 feet-per-second (fps).
The latest bullet maker to step up to the plate with a vastly improved bullet design for today's high performance muzzleloading big game rifles is Hornady Manufacturing Company (PO Box 1848, Dept. GWK, Grand Island, NE 68802; phone: 800-338-3220; on-line: www.hornady.com). Their new Super Shock Tipped (SST) muzzleloader bullets, now available for .50- and .45-caliber big game rifles, are constructed with many of the same features and technology found in the Hornady line of SST centerfire rifle bullets.
It's the very aerodynamic shape of the SST muzzleloader projectile that first catches the eye. This bullet is anything but another "flying ash-tray" like the big jacketed hollowpoint bullets most of us have been shooting with sabots for nearly 20 years. The SST is a very sleek, polymer-tipped spire-point projectile that shouts, here is a serious big game hunting bullet!
However, the beauty of this muzzleloader bullet is far more than what first meets the eye. Hornady pulls from its centerfire rifle bullet technology and uses a jacket of tapered thickness, with the copper heaviest at the base, then tapering in thickness toward the polymer tip. Inside the jacket, not quite half way up the length of the SST, is Hornady's "InterLock" ring.
The combination of the polymer tip, the tapered jacket thickness, and InterLock construction, results in a bullet that Hornady claims will readily expand, yet will hold together better at today's higher muzzleloader velocities than the thin-skinned jacketed hollowpoint bullets we've been shooting for years.
Today's muzzleloading big game rifles are shooting faster, flatter and farther than the muzzleloaded hunting rifle of just 20 years ago. Since the mid 1990s, Knight, Thompson/Center Arms, Traditions, Connecticut Valley Arms, and just about everyone else who has marketed a modern in-line rifle, have all promoted the use of "Magnum" 150-grain Pyrodex Pellet powder charges.
And now we have Hodgdon's new Triple Seven, a new and hotter blackpowder substitute that gives nearly the same velocities as the 150-grain Pyrodex Pellet charges with as little as 100 grains. With such charges, today's more advanced in-line rifles are pushing a saboted 250-grain bullet out of the muzzle at 2,000 to 2,200 fps.
Just 20 years ago, muzzleloading rifle manufacturers were claiming a 100-grain charge of blackpowder or Pyrodex as the "Maximum Recommended Load" for their guns, and that 100 to 125 yards should be considered the maximum effective range.
Now, practically all are touting the 200-yard effectiveness of their rifles and recommended loads. Unfortunately, most of the saboted bullets being shot by the majority of in-line toting muzzleloading hunters, haven't exactly been the best choices when the range approached or surpassed the 200-yard mark.
One of my favorite bullets for shooting with a sabot out of a .50-caliber fast-twist (1-in-24-inch to 1-in-28-inch) bore has been the .452-inch diameter 250-grain Hornady XTP. This bullet has a ballistic coefficient (BC) of just .147. If I can get that bullet out of the muzzle of a 24-inch .50-caliber barrel at 2,000 fps, the load generates 2,220 foot-pounds of energy (fpe). Due to the poor BC of this jacketed hollowpoint, by the time it reaches 200 yards, it has slowed to around 1,175 fps and retains just 765 fpe. At that distance, the game-taking efficiency of this bullet has been greatly diminished.
On the other hand, Hornady's new 250-grain .452-inch SST for loading into the same .50-caliber barrel with the same powder charge, would leave the muzzle at the same velocity and with the same muzzle energy. However, this bullet has a very high .240 BC, and thanks to the much improved frontal shape and sleeker aerodynamics, this bullet maintains velocity and energy greater at longer ranges.
40% More Energy
In fact, out at 200 yards, an SST that left the muzzle at 2,000 fps would still be moving at around 1,425 fps and would hit a whitetail with right at 1,125 fpe. That's about a 40% increase in retained energy simply due to the SSTs higher BC. For comparison, the 300-grain Hornady SST has a BC in the mid .290s, while the 300-grain .452-inch XTP has a BC of just .181. (A 200-grain .400-inch SST bullet will be available for the .45-caliber rifles. It will have a BC of around .225.)
While I still shoot a number of different in-line ignition muzzleloaders, several seasons back I went to the new .50-caliber Savage Model 10ML II "smokeless muzzleloader" for practically all of my hunting. With powder charges consisting of medium burn-rate smokeless powders such as Vihtavuori N110, IMR-SR4759, IMR-4227 and Accurate Arms XMP5744, this rifle will get saboted bullets out of the muzzle at velocities that are easily 10 to 15% faster than possible with Pyrodex or Triple Seven charges out of any other muzzleloader.
And this increase in velocity also means a jump in killing energy. Plus, thanks to the non-fouling, non-corrosive nature of these powders, I don't have to spend all that time always cleaning the Model 10ML II rifles.
The very first time I saw Hornady's new SST bullet design, I knew this was the bullet I had been waiting for to shoot in the Savage muzzleloader. Fortunately, the folks at Hornady were just as curious to see what the new SST bullet would do at the higher velocities produced by the Model 10ML II and sent me a few hundred of the first 250- and 300-grain .452-inch SST bullets to come off the line.
When shooting the Savage muzzle-loaders, or any other muzzleloader, for accuracy, I always take time to run each and every bullet across my RCBS digital electronic scale, separating them into groups of bullets that are all within 2/10ths of grain of each other. No matter whose name is on the box, I generally find a weight variation of around 1-grain from light to heavy.
In other words, 250-grain bullets just about always run from around 249.3 to 250.3 grains. When I sat down and weighed exactly 100 of the new 250-grain SST bullets, I discovered that I had a maximum weight variation of just 3/10ths of a grain-249.8 to 250.1 grains. I was impressed.
Now, the new bullets did not arrive until mid-May, and temperatures were already beginning to warm up. Most days got into the mid-to upper-70s quickly. To date, I have now logged more than 24,000 smokeless rounds through about a half-dozen Savage test rifles, and the one thing I've noticed most about the smokeless loads is that they do tend to warm up the barrels quickly. In very warm to hot temperatures, the barrels on these rifles can be extremely slow to cool down.
And if there is one thing that will destroy accuracy with saboted bullets, it's a hot barrel. The heated metal makes the plastic sabot softer and more pliable. The condition makes it tough to shoot good groups with almost any powders, but it is even more affected by the smokeless loads shot in the Model 10ML II. The higher pressures created by these powders will blow the soft plastic of the sabot, making it impossible to get any degree of accuracy.
Fortunately, an extended cool front moved down into eastern Missouri where I live, giving me several early morning shooting sessions with temperatures in the upper 40s. Still, I backed off my favorite 43-grain charges of both Vihtavuori N110 and IMR-SR4759 to 42 grains. The accuracy of the new SST was all I had hoped for.
A 42-grain charge of Vihtavuori N110 pushes the bullet out of the muzzle of the 24-inch Savage barrel at 2,338 fps, which translates into 3,037 fpe. The bullet consistently printed 100-yard groups of around 1° inches. However, my best accuracy with the 250-grain SST came with a 42-grain charge of IMR-SR4759 behind the polymer-tipped spire-point bullet. My ShootingChrony chronograph showed a slightly slower velocity of 2,311 fps, which is still good for 2,962 fpe.
Several of the half-dozen groups shot with this load printed well under 1-inch across center-to-center . . . including the best group I've ever shot with one of the Savage Model 10ML II rifles. That 3-shot group was one slightly out-of-round hole in the target paper that measured barely -inch center-to-center.
Oddly, the 300-grain SST only shot so-so with either of these two powders. My best 100-yard groups with either powder were generally around 1 inches across, with some opening to just over 2 inches. But for such a big bullet at 2,200 to 2,225 fps (3,220 to 3,300 fpe), this is still pretty good accuracy. In the accuracy department, the 300-grain bullet came into its own right with a 46-grain charge of IMR-4227. Several of the 100-yard groups shot were under 1-inch across, including a very impressive °-inch 3-shot cluster. This load was good for around 2,150 fps, with 3,075 fpe.
Another cool 50-degree morning around June 1st broke dead calm, giving me one last opportunity to check out the long-range accuracy of the SST bullets. I sighted one of my Model 10ML II rifles to hit dead on at 200 yards. The rifle had just been fitted with a new 4-12x44mm scope and machined one-piece steel Picatinny-style base, both from Leatherwood/Hi-Lux Optics, and I was just as eager to check these out as much as to see what the SST bullets would do at extended range. My first 3-shot 200-yard group with the 250-grain SST and 42-grain charge of IMR-SR4759 printed inside of 3 inches, and my second was right at 2-3/8 inches.
I then moved the target board back to 250 yards, and took one shot to determine the bullet drop. I then placed a 2-inch Birchwood-Casey stick-on Targ-dot 12 inches directly above the bull. The next five shots with the 250-grain Hornady SST grouped inside of 4 inches.
Now, in the past, I have often had to hunt with in-line rifles loaded with saboted bullets that did good to shoot inside of 4 inches at 100 yards. So, it was very understandable that I was elated to see such a good group (near the center of the bull) all the way out at 250 yards.
When I first went to range to test the new SST bullets, I attempted to load and shoot them with the same Muzzleload Magnum Products (MMP) high-pressure sabot I had used very successfully with the 250-grain XTP bullets in the Savage smokeless muzzleloader. I could not get any degree of accuracy at all with the long 300-grain SST, and only mediocre groups with the slightly shorter 250-grain bullet.
When I head to the range with something new, I always take along a shooting box that contains just about every sabot known to man. Inside that box were some of the High Pressure Hornady (HPH) sabots that MMP produces for the company.
The HPH is basically made from the same polymer (plastic) as the standard MMP high-pressure sabot, however, it features a slightly different base and longer petals, or sleeves on the cup. Instead of the smooth concave surface that cups into the base of the sabot, like that found on the standard high-pressure version, the HPH base features a series of stepped rings.
Whether it was the difference in the base or the longer length of the petal that did the trick, I don't really know. But the new SST bullets shot great with the HPH sabot. And this is the sabot Hornady will be packaging with this bullet.
In an attempt to get accuracy with the bullets at higher velocities, I experimented with placing a separate sub-base and several lubed felt wads beneath the saboted SST bullets. I did manage to get velocity with the 250-grain bullet up to 2,400 fps with a 45-grain charge of Vihtavuori N110 and shot several 2- to 2°-inch, 100 yard groups.
The sub-base was nothing more than just the base portion of an MMP high-pressure sabot, with the sleeves clipped off with a pocket knife. This was run down onto the powder charge first, followed by two .50-caliber Ox-Yoke "Wonder Wads." The sabot was then seated on top of all this. The approach works fairly well, and protects the forward sabot from excessive pressure. Recovered from the ground 10 to 15 yards from the muzzle, the sabots looked fine.
Today's muzzleloading rifles have advanced pretty far, and now with bullets like the Hornady SST, shooters everywhere are going to discover a whole new level of muzzleloader performance. And with the tough new space-age plastics being formulated, it's only a matter of time before someone comes up with a sabot that's resilient enough to resist the heat of summer shooting, but still soft enough to grip the bullet and the rifling of the bore.
(Toby Bridges is the host of the High Performance Muzzleloading (www.hpmuzzle-loading.com) website, and the author of several current best selling books on the topic-Muzzleloading from Creative Publishing International, and Advanced Black Powder Hunting from Stoeger Publishing Company.)