Posted on: 2011-05-08 13:00:00 -0400

I gathered my first good set of data on the zero shift of each of my AAC SPR/M4’s five different attachment settings. For this task, I used a 100-yard target with a mil grid and diamond aiming point matching Storm Tactical’s zero/call data page. My previous attempt used standard NRA-style bullseye targets and sketches in my shooting notebook, which could hardly be considered precise. My shooting also changed between the two attempts in that I used my fist to support the toe of the stock on my first attempt and a rear bag this time.

The zero shift appears to vary between 0.1 and 0.5 mils depending on the setting. The good news is that setting 1 produced the least shift both times and setting 4 the most. But the groups shot with the bag showed less overall shift. I’ll need to gather more data before saying anything for sure.