As many reports yesterday indicated, the 21-year-old Allen, Texas man who opened fire at an El Paso Walmart store posted a rambling manifesto online just before his attack. In his anti-immigrant, anti-corporate/technology, pro-environmental views, he was clearly sympathetic with and inspired by the New Zealand mosque shooter, as was the Poway synagogue shooter.

Here’s a brief section of what the killer wrote about his choice of weapon:

Main gun: AK46 (WASR 10) – I realized pretty quickly that this isn’t a great choice since it’s the civilian version of the ak47. It’s not designed to shoot rounds quickly, so it overheats massively after about 100 shots fired in quick succession. I’ll have to use a heat-resistant glove to get around this.

8m3 bullet: The bullet, unlike pretty much any other 7.62×39 bullet, actually fragments like a pistol hollow point when shot out of an ak47 at the cost of penetration. Penetration is still reasonable, but not nearly as a normal ak47 bullet. The ak47 is definitely a bad choice without this bullet design, and may still be with it.

The other gun(if I get one): the ar15 – Pretty much any variation of this gun doesn’t heat up nearly as fast as the AK47. The round of this gun isn’t designed to fragment, but instead tumbles inside a target causing lethal wounding. This gun is probably better, but I wanted to explore different options. The ar15 is probably the best gun for military applications but this isn’t a military application.

This will be a test of which is more lethal, either it’s fragmentation or tumbling.

I didn’t spend much time preparing for this attack. Maybe a month, probably less. I have to do this before I lose my nerve. I figured that an under-prepared attack and a meh manifesto is better than no attack and no manifesto.

– Manifesto posted by the El Paso Walmart shooter shortly before he murdered 20 people and wounded another 26.