Posted: 3/28/2006 7:28:03 PM EDT
[#4]
Here is part of the letter I wrote to stag accompanying the upper. Stag Arms,
My Stag 16" M4 upper was purchased brand new from gandrtactical.com. Included all documentation and hanging tag stating that the upper passed all function tests.
First day at the range, I shot 90 rounds of Winchester .223 55gr FMJ. 89 Rounds shot fine and one jammed where the carrier/bolt slid right over the top of the magazine, or the bolt went back half way, and then got stuck on top of the mag. I was unable to tell.
The next visit was to an indoor range where I am required to shoot their ammo, Winchester Q3131. 5.56mm 55gr FMJ. The first few rounds shoot fine, and then after that it's one or two at a time before the rifle either doesn't cycle another round, or tries to, and jams it between the feed ramps and the magazine, putting a nice dent in the casing from the bolt head.
Sounding like an ammo problem, I went to the range master and asked for something different. He gave me Federal American Eagle .223 ammo. 40 rounds shot fine, but it did not lock the bolt back after the last round was fired. Please note that another AR15 shooter with a 16" RRA carbine shot the Q3131 just fine, during the same visit at the range, signifying that the ammo should be OK.
I went home, cleaned and lubricated the rifle, and gave it another try a week later. Same results with both ammo.
I have tried different magazines and did not solve the problem. Regularly, I use almost brand new D&H teflon coated mil sepc mags.
Becoming extremely frustrated with my brand new rifle, I decided to take a closer look at the upper. I noticed what appears to be abnormal wear on the carrier end of the gas tube. I decided to remove the gas tube and see what the opposite end looked like. What I saw was abnormal carbon buildup, designating a gas leak to my knowledge, causing the horrible short stroking.
The gas key feels solid, but I was told that the bolts aren't staked correctly.
After each range visit, the rifle was cleaned and lubricated using BreakFree CLP.
The upper is mounted to a Stag Arms lower, using an RB Precision lower parts kit.
The rifle has not been shot since the gas tube was removed for inspection.
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