During a Firearms Instructor Development Course there was an ammunition malfunction which resulted in a destroyed rifle. The officer was conducting barricade work, shooting steel at about 65 yards, using his personally owned rifle, a Rock River M4.
The investigation showed this was caused by a telescoping round. This occurs when the actual bullet is not crimped properly to the casing. When it is fed from the magazine by the bolt assembly it telescopes backwards into the casing, causing a huge increase in pressure.
I encourage everyone to regularly inspect the ammunition in the duty magazines. If you load and unload, make sure that you aren’t using the same round over and over.
This shooter was not injured because of proper use of safety equipment Glasses and hearing protection.
A good emergency plan with a medical kit couldn’t hurt.
Featured Photo courtesy of Amoryblog.com.
Cracked Barrel extension
Bolt
Broken Bolt Carrier
Upper Reciever blown up
Bolt facce
Expanded Bolt Carrier
Ejection Port
Mag well view