Wednesday, August 23, 2017

Aluminum Cased Ammo

I have nothing in particular against the stuff, indeed my carbine shoots its smallest groups using Blazer aluminum cased 180 grain ammo. The issue here is that when using this stuff in a carbine, the pressures are higher. As an example I recorded 1400 fps from the above mentioned Blazer, a boost of 250-300 fps over what I'd see from my pistol.

The extra  velocity means extra strain on the cases and for 2 of the 15 I shot last weekend, it was a bit too much.

When this happened I noticed a bright flash from the ejector port and picked up a black powder stain on my index finger. I was pulling the trigger with my middle finger as I'm missing a bit of my trigger finger. Interesting pattern, no?

I was recording all my muzzle velocities but didn't think to note which shots were the ones on the blown out cases. Checking the numbers however I see that all the velocities were very consistent around 1403 fps except for two at 1382 and 1375. So not much loss but noticeable if you're looking.

2 comments:

Merle Morrison said...

this creates a problem with gas erosion in the chamber - and possible problems with gas going where it isn't supposed to!

Merle

wildriver said...

Good visual of gas cutting for those of us who never see the effects on cast bullets.