Parts Diagram - Hornady 366

He decided to strip the primer system first. He loosened #58, caught the detent ball (#63) with a magnetic pick-up tool just as his own note predicted, and slid out the primer slide. There—wedged under the slide, invisible to any inspection port—was a flake of crimped brass from a military .45 case. A tiny shard, thinner than paper. That was the sponge in the stroke.

He pulled the diagram closer. Under the lamp, the paper had yellowed at the folds. He’d drawn his own notes in the margins over the years: “#27—replace every 5k rounds,” and “#63 (detent ball) WILL fly across room. Use magnet.” The diagram was no longer Hornady’s document. It was Arthur’s diary.

The 366 had simply stopped feeling right . The stroke was spongy. The index pawl hesitated. A single #209 primer had failed to seat yesterday, crushed sideways in its pocket like a tiny, silver pancake. That one misfeed meant distrust. And in reloading, distrust meant you pulled the handle again, slower, listening. hornady 366 parts diagram

Arthur wiped the diagram clean of graphite smudges and refolded it along its ancient creases. He slid it back into the manual’s pocket. The 366 wasn’t just a reloading press anymore. It was a map of decisions—Hornady’s engineers on one side, his own repairs on the other. And between them, the trust that came from knowing exactly where every spring, pin, and punch lived.

He reassembled the 366 by the diagram’s reverse order. Lower tier, then upper. Cam followers greased. Pawl timed to the shell plate’s detent. When he finished, he dropped a primed case into station one and pulled the handle. He decided to strip the primer system first

He traced the primer system first. There it was: the Primer Slide (#39), a tiny steel boat that ferried primers from the drop tube to the seating punch. Next to it, the Primer Slide Spring (#40)—a fragile coil no bigger than his pinky. That , he thought. That’s the liar.

Arthur’s eyes drifted to the upper tier: the Powder Slide Assembly (#85–92). The diagram showed the brass powder bushings nested like Russian dolls, the metering insert (#88) drawn with an almost anatomical precision. He remembered buying the machine used, finding an old #88 clogged with Unique powder that had turned to lacquer. The previous owner had never cleaned it. Had never looked at this diagram. A tiny shard, thinner than paper

So Arthur did what he always did when a machine lied to him. He reached for the diagram.

His gaze settled on the part he’d never needed: the Primer Seater Punch (#43). In the diagram, it looked like a tiny mushroom—a flat face on a steel stem. But the callout box added a warning: “Seater depth adjustable via locknut. Do not overcam.” Arthur had read that note fifty times. Tonight, he realized what it meant. The 366 didn’t have sensors or computers. It had geometry. The punch’s travel was governed by a cam slot in the main shaft. If you over-cammed—if you forced the handle past its natural stop—you didn’t just crush a primer. You bent the punch stem. And a bent stem didn’t show on the outside. It showed in the feel, a year later.

But he checked the seater punch anyway. He rolled it on a piece of float glass. A whisper of a wobble. Not bent. Just… tired.

He didn’t have a replacement. But the diagram reminded him of something: part #44, the Seater Punch Return Spring. If the spring was weak, the punch would drag. He replaced it with a spring from his spares jar—a generic coil that was 0.002 inches thicker.