My Rifle Brass Annealer

[Crusty]

Here's my rifle brass annealer in operation as the first step in reloading precision long range rifle ammunition. I don't think I even wrote anything down as I built it much less any sort of documentation. I used a rotisserie motor for drive, a 10mm XL timing belt (5mm pitch) and sprockets (40:26 ratio to achieve 6 sec rotor revs from the 10 sec motor revs), half inch shaft stock, cheap bearings I bought at the local hardware store, various aluminum pieces from my materials bin and a cake pan. The frame is 1/4" mdf with an aluminum sheet overlay on the front and a mahogany perimeter frame. You can't see them in the video but there's finishing nail pins that guide the cases from the input slot into the heating position.

The big discovery for me was that if the cases landed on a downward moving surface they tended to stop rotating and skidded in place, but when I offset the top rotor so that they landed on an upward moving surface then rotation became reliably 100%. A rotor diameter of around 2" gives enough rotations for uniform heating.

The angular relationship between the two slots is adjusted to achieve the desired heating time (best determined empirically with Tempilaq) and in the video it's set for 5-5½ seconds, which puts my cases in the 700-750º range. Each rotor is fastened to its driving shaft with two grub screws so it's simple and easy to adjust the relationship between the two. A small flame with the tip of the inner cone directed at the neck/shoulder junction (barely visible in the video) is adequate to reach the target temp range.

[mklotz]

Very clever implementation of the feed mechanism. I will endeavor to remember that.

[Crusty]

It sure beats spinning cases in a deep socket on my screw gun while counting seconds.

[Bony]

I have very little knowledge about ballistics or firearms, and there being no such thing as a silly question I ask why it's necessary to anneal the cases? Is it because upon the initial firing the brass hardens and would possibly burst upon a second firing if not annealed?

[hemmjo]

Firing stretches the brass to “fit” the chamber. The reloading process resizes the brass so it chambers more easily. Then it is fired again...sized again, etc. The neck is also crimped on the bullet each time in many situations.

This work hardens the brass.

[Toolmaker51]

Hereabouts, likely one of the best endorsements of a project comes from Marv K. "Very clever implementation of the feed mechanism. I will endeavor to remember that." Figure you just scored a 1000 yard X ring. . .
I agree, the cartridge timing and positioning mechanics are ideal. I really like the style Geneva gear action.
I have 1500+ .308 Winchester [M1A] and just as many .30-06 Springfield [M1] begging I duplicate your project.
Poor guys, totally unaware getting 6500 sq/ft of drywall in comes first.

[Crusty]

I'll tell you what, I shoot the longest range with a caliber that's not supposed to be able to do it and sometimes it turns out not too shabby and I'm a believer in annealing before every reload so that I get consistent bullet seating depth and consistent bullet release from every round, plus the icing on that cake is the extended brass life: the brass used in the video for testing was some OK but nothing special Hornady brass that I got 19 reloads out of before I retired it because I was getting 10% split necks. And the annealer's beau coups faster than annealing by hand.

I'd never thought about it but it does look like a Geneva mechanism however it's really just one slot to deliver the brass into the heating position at the right time and then another to remove it at the right time integrated into the brass roller. The rotors are kept synchronized by the unseen timing belt and sprockets driving them. Be sure to run some tests with Tempilaq to determine your timing - most of the videos of home built annealers way overheat the brass and that's a bad thing to do.

[McDesign]

That is really, really nice!

[Toolmaker51]

I load a bunch of calibers; .17 Remington to .375 H&H and .45-70, plus common handgun calibers. It's so rewarding; analyze brass and targets, making a load perform where it didn't [or shouldn't, lol] before.
Using a timing belt, means you could have different case spools. . .better than varying torch placement for good temperature control. And once a combination is set, easily recorded and duplicated.

[jimirwin]

I've seen other videos of this type of design. None show build details. I'd love to build one but need some sort of materials list and idea of dimensions.
How 'bout it? Would be cool to make one myself.

Thanks and good job!

Jim