The Firing Line Forums - View Single Post - Magpul Dynamics "Dynamic Carbine" 1&2 (A VERY surprising Colt failure)

Powderman · November 18, 2009, 01:07 AM

I think I might be able to give an insight...

Your Colt was probably not defective; indeed, the manner in which it failed--forcing all the debris forward and to the side--might have saved you from serious injury.

Here is what probably haoppened...

If the ammunition for your rifle is not properly crimped, upon the feeding stage it will force the bullet back further into the case. This is especially true for the long bullet .223 loads. The round still chambered; but upon firing, pressure spiked and vented away, causing the upper receiver and BCG failure pictured.

What kind of ammunition were you using? Hopefully it was factory; if forcing of the bullet into the case was indeed the cause, they might owe you a new rifle.

I carry an LE 6920 on duty, and I shoot both factory/issue ammunition in it (Federal TRU 55 grain JHP) and my reloads. All of my .223 reloads get a heavy crimp from a Lee Factory crimp die to prevent exactly what you experienced.

November 18, 2009, 01:07 AM	#2
Powderman Senior Member Join Date: September 7, 2001 Location: Washington State Posts: 2,166	I think I might be able to give an insight... Your Colt was probably not defective; indeed, the manner in which it failed--forcing all the debris forward and to the side--might have saved you from serious injury. Here is what probably haoppened... If the ammunition for your rifle is not properly crimped, upon the feeding stage it will force the bullet back further into the case. This is especially true for the long bullet .223 loads. The round still chambered; but upon firing, pressure spiked and vented away, causing the upper receiver and BCG failure pictured. What kind of ammunition were you using? Hopefully it was factory; if forcing of the bullet into the case was indeed the cause, they might owe you a new rifle. I carry an LE 6920 on duty, and I shoot both factory/issue ammunition in it (Federal TRU 55 grain JHP) and my reloads. All of my .223 reloads get a heavy crimp from a Lee Factory crimp die to prevent exactly what you experienced. __________________ Hiding in plain sight...