300BLK Subsonic 60-shot 100-yard Example
- Shots: 60
- Distance: 100 yards
- Ammunition: Handloaded
- 225gr Hornady OTM
- 9.2gr IMR4227
- 2.20" COAL
- Match-grade primers (a mix of FG205M and Rem 7.5 were used, with the latter appearing to be marginally hotter and more variable than the former)
- Remington 300BLK cases
- Barrel: Noveske 16" 1:7 stainless with AAC Cyclone suppressor (note that this load will not cycle the action without a suppressor)
- Action: Noveske AR-15 with pistol-length gas tube
- Conditions: 50F, 60%RH, minimal wind
- Precision: 0.80MOA
In contrast to the 300BLK Subsonic 20-shot 100-yard Example, which was done with factory ammunition, these handloads exhibit much less variation in muzzle velocity: standard deviation is 16fps compared to 32fps on the factory ammunition. This variance is still significant at this speed and range, however, so the group is still noticeably elongated along the y axis.
Media:300BLK 225gr IMR4227 subsonic 100yd.xlsx contains the raw data and analysis.