Getting The Most Out Of The Trophy Bonded Tip Bullet
March 28, 2018
Federal's Trophy Bonded Tip (TBT) bullet is perhaps my all-time favorite projectile for hunting big game. In 2014 the 180-grain .30 caliber version provided a dozen one-shot kills for me in Namibia, including a superb kudu bull, and in 2015 I used the same bullet to drop a huge public-land bull elk in Utah—a tag that took me 17 years to draw. I trust the TBT, and with good reason: It's never let me down.
However, until now the TBT has never been available as a component. Before diving into techniques that will help you get the most out of the TBT, let's take a look at the bones of the bullet. Its roots lie with the legendary Trophy Bonded Bear Claw, which is a flat-based bullet designed primarily for reliable expansion and deep, deep penetration. It earned its stripes on dangerous game.
The TBT is a streamlined, tipped and boattailed version engineered to offer better downrange velocity and energy retention coupled with terminal performance optimized for deer- to moose-size game. The TBT pairs a solid copper rear shank with a lead front core that is robustly bonded to the jacket. Nickel plating provides a lubricious coating that also protects the bullet from corrosion.
Just aft of the tip, the jacket mouth is skived to enable fast, predictable upset. The fast upset is initiated by the TBT's heat-resistant composite tip, which also serves to protect bullets in the magazine from getting battered during recoil and significantly aids aerodynamics.
The jacket tapers aggressively from the tip to slow expansion and stabilize it in the classic mushroom shape. Bonding between lead and copper—plus that solid copper rear shank—makes for outstanding weight retention, which translates into deep, bone-breaking penetration.
I've recovered only a few of the TBT bullets I've taken big game with because they almost always achieve full penetration. The ones I have recovered almost always display perfect mushrooms—even those that struck heavy bone. One last design element is worth mentioning; The TBT's tangent ogive takes rifling forgivingly and consistently, enabling the bullet to shoot accurately in a broad selection of different chamber throats and rifling types.
To research how to get the best performance when handloading TBT bullets, I spoke with Paul Furrier, Federal's chief engineer in the propellants division.
According to Furrier, the TBT is a dense bullet with compression characteristics similar to the Barnes TSX, Swift A-Frame, Nosler AccuBond and other extra-tough big game projectiles, and it takes the rifling leade in similar fashion. In other words, seating firmly against the rifling leade may cause pressure spikes, and Federal recommends against it.
Thankfully, the TBT "jumps" a bit of freebore comfortably while still providing excellent accuracy. "Being primarily a factory-ammunition company, Federal leans toward designing bullets to perform best at standard SAAMI overall length seating depths," Furrer said. "As a result, we haven't experimented with various seating depths as extensively as the handloading user base no doubt will. However, we have experienced great results in seating between .050 and .080 inch off the rifling. I think users will find this is a very jump-tolerant bullet."
Load data are already available in PDF form on Federal's website (search "trophy bonded tip reloading data"). The data include many popular cartridges and a few vintage rounds. If your favorite isn't included, it doesn't hurt to call Federal's customer service line at (800) 379-1732 and ask for guidance.
"We often get asked for additional data," Furrier said. "Within reason, we forward those requests through customer service and do our best to provide relevant information. There's no end to the combinations that can be tried, but we do our best."
Furrier pointed out that because of their construction, TBT bullets are larger than like-weight traditional cup-and-lead-core bullets. "Case volume gets constrained a bit as a result," he said. "We can't get quite the velocity with the TBT as we can with traditional cup-and-core bullets by Speer, Sierra, Hornady or what have you. There's too much intrusion into the case and too much bearing surface."
In short, within SAAMI pressure constraints—even with the newest propellants available—traditional bullets can be pushed faster because of the construction, the bearing surface and the relative density. However, losing a few feet per second is well worth the trade-off for the TBT's on-impact terminal performance. Plus, it's a fairly aerodynamic bullet and will maintain downrange velocity more efficiently than traditional flat-base bullets.
Loading to longer-than-spec in chambers cut with long throats reduces the intrusion inside the case and enables cautious handloaders to boost velocities, closing the performance gap. However, be sure to seat TBT bullets a minimum of .020 off the leade.
On the subject of downrange performance, I asked Furrier about the TBT's velocity expansion window. "Our engineers have probed the low end more intensively than the high end," he said. "They found good expansion reliable down to 1,700 fps. We haven't rigorously tested the upper end—the TBT just isn't a blow-up type of bullet simply because of its construction. It performs reliably even at velocities in excess of 3,400 fps in cartridges such as the .300 Ultra Mag."
I can attest to the TBT's toughness and ability to withstand high-velocity impacts. On the bull elk I mentioned at the beginning of the article, the shot was only 70 yards, so the 180-grain TBT—fired out of a Kimber .300 Win. Mag.—was still moving in excess of 3,000 fps when it hit. It punched through the shoulder bone and spine and still mushroomed perfectly.
When compared to like-weight traditional bullets, TBT projectiles are longer. Very long bullets can be hard to stabilize, and many bullet manufacturers of extreme-BC, VLD-type bullets now print minimum rifling twist rates on component-bullet boxes. However, TBT bullets aren't so long they are twist-rate sensitive.
"We've had no reports of any destabilization issues in our factory ammunition, and when using standard-for-cartridge twist rates, handloaders won't either," Furrier said.
Boiled down to its basics, the Trophy Bonded Tip bullet is an extremely tough, reliable bullet, and it couples easy-accuracy forgiveness with better-than-adequate ballistic coefficients.You can't ask for more than that.