Bullet Bio: Hornady InterLock

by
posted on November 11, 2015
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
hornady_interlock_bb.jpg

It was, by all measures, a miserable hunt. Two days prior I had busted my wisdom tooth and it was hurting like the devil. I was crumpled in pain at the base of a big poplar tree, almost moaning in agony with my Savage 99 across my lap. Had my freezer not been empty and had I not been waiting 12 months to be where I was, I’d have packed it in. In fact, it was noon and I was just about to do that anyway. 

Then, like they often do in the whitetail timber, things happened fast. A doe burst from thicket to my front, ran down into the little hollow I was watching and then cut to her right. She had it in high-gear and didn’t stop until she’d found the cover of the laurels. I flipped up the peep sight on my 99. When she stepped in the clear at about 130 yards I pulled the trigger and sent a 100-grain Hornady InterLock on its way. For a moment or so after that, my tooth did not hurt.

The Hornady InterLock is a cup and core bullet. That means that the gilding metal jacketwhich is 95 percent copper and 5 percent zincis formed in a press from a disk of material. When the jacket begins to resemble the shape of a bullet, a slug of 97 percent lead and 3 percent antimony is inserted and the forming process continues. The bullet gets its name from a raised rib or ring on the inside of the jacket near the bullet’s base. This inner ring helps to lock the bullet’s core to the jacket during expansion. The cannelure just forward of the ring allows for precise crimping and, in a way, works similar to the inner locking ring. In this fashion, the InterLock has been killing critters for almost 30 years. It was introduced in 1977, and is one of my favorites among offerings that might be considered both affordable and conventional big-game bullets. This is partly due to a reliable terminal performance, but also because of the bullet's tendency to shoot very straight. I’ve handloaded for a dozen or so .250 Savage and .257 Roberts rifles, and the 100-grain InterLock has always been one of the most accurate bullets for both.

Typical of most cup and core centerfire rifle bullets, the InterLock needs to impact at about 1700 fps to provide measureable expansion. This, of course, only applies to InterLocks designed for and loaded in common high velocity big game cartridges like the .243 Win., .30-06 Sprg. and such. InterLocks loaded for slower big game cartridges, like the .30-30, .405 Win. and the .444 Marlin will expand at even slower velocities.

I trusted an InterLock when I was hunting big axis bucks in Texas with a .300 Win. Mag. and I trusted them when I was hunting fallow deer on the Earl of Rosse’s estate in Ireland. For many years the InterLock was the bullet Hornady loaded in its Custom line of ammunition. The company still offers it, there but it's also available in the more affordable line of American Whitetail ammo; most of which retails for just a little more than a dollar per shot. The InterLock is old and simple, but hunting bullets don’t hang around for 30 years if they don’t work.

Latest

Photo 03 Ammo On Buffalo
Photo 03 Ammo On Buffalo

Behind the Bullet: .450/400 3” Nitro Express

Among the lot of Nitro Express cartridges—a term coined by James Purdey to compare the power of these cartridges to a locomotive and newly loaded with smokeless powder—the .450/400 3” N.E. represents one the best blends of hunting power and ease of shooting. Curious? Read on, as Phil Massaro goes in-depth on this classic, though esoteric, favorite.

TriStar Arms to Exhibit at 2026 NRA Annual Meetings & Exhibits

TriStar Arms will exhibit at the NRA Annual Meetings & Exhibits, taking place April 17–19, 2026, in Houston, TX. Attendees are invited to visit TriStar Arms at Booth #3103 to explore the newest firearm offerings and learn more about the brand's continued commitment to the shooting sports community.

New for 2026: Left-Handed Ruger American Gen. II

Ruger has introduced left-handed models of the Ruger American Rifle Generation II. The first of these models will be released in the Ranch configuration, with six chamberings available: 7.62x39mm, 450 Bushmaster, 400 Legend, 350 Legend, .300 Blackout and 5.56 NATO.

New for 2026: Swhacker #307 Mechanical 2-Blade Broadhead

Swhacker Broadheads has launched its #307 100-grain Mechanical 2-Blade Broadhead. This latest addition to Swhacker's lineup promises precision engineering with reliable deployment, coupled with accuracy and devastating field performance.

Keys to the Eastern Turkey Hunt

A turkey is a turkey regardless of subspecies, sure, but best hunting tactics often vary depending on geographical location due to the birds’ varying behavior. Translated, killing turkeys back East is different than killing them out West. Check out some Eastern-specific tips below, and stay tuned for a follow-up targeted at our Western readers.

Montana and Utah Celebrating 125th Anniversaries

Two 125th Anniversaries are occurring this year, the first being for the entire Montana FWP, and the second being a key piece of property in the history of the Utah DWR.

Interests



Get the best of American Hunter delivered to your inbox.