10-19-2019, 07:22 AM
Milspec steel for M4/M16 bolts is 8620 with specific heat treating requirements. A number of manufacturers use different steel alloys and different heat treating so it definitely is not a one size fits all scenario.
Additionally, 5.56 is rated for up to 62,000 cup while 6.5 Grendel is 52,000 cup, so there is a significant difference in pressures at open time. The further down the barrel the gas port is located and the size of the gas port also affect unlock pressures.
Additionally, 5.56 is rated for up to 62,000 cup while 6.5 Grendel is 52,000 cup, so there is a significant difference in pressures at open time. The further down the barrel the gas port is located and the size of the gas port also affect unlock pressures.