We used Magtech .223 ammo until they got a military contract and couldn't keep up with production. If fairness, they told us 6-8 months in advance that they were pretty sure a contract was coming and that we needed to make sure we had another supplier available in the event they got it. Magtech has been the cleanest of all the ammo we used followed closely by Privi Partizan. I try to avoid Federal and will only use them if no other suppliers are available with the exception of the .50 BMG round.
We are currently using Wolf Gold series of brass case ammo. We've gone through over 500,000 rounds with zero issues. It burns clean and pretty damn close to 5.56mm spec's even though it's listed as .223 Remington.
I'll never shoot my Colt M4s like that, for sure.10/1/2016
Here is a Colt M4 that lasted exactly 364 days on the line. This is from a group of Colt's that the RSO's always go to first because of the ease of operation and the "cool" Magpul tan furniture for the customers. These started life as semi-auto M4's with 16" barrels. We estimated that a very conservative round count for this rifle to be at approximately 150,000 rounds.
Here some of the repairs that have been performed on this rifle during it service life.
- four hammer pins
- hammer spring
- ejector spring
- two bolts
- gas rings
- gas tube
The barrel was still shooting straight enough to put holes through the center of the target and group good enough for tourists. There were no signs of "keyholing", no other signs of stress cracks in the upper or lower receiver assemblies.
We don't know at what point the barrel separated from the upper receiver because the customer posed with the gun and then handed it back to the RSO in two pieces. The customer had just finished firing the weapon, handed it to the RSO, who then cleared it and gave it back to the customer for cleaning.
In my opinion, the Colt M4's have worked the best they could considering the environment they have to function in.