So far, 35 members on here have discovered that the carrier in their newer build 556 rifle is hitting the receiver causing damage to the carrier. Please check to see if your rifle has the same issues so we can try to identify a problem batch.
This interference may be causing accuracy issues since it causes the carrier to bind just before coming all the way forward. But more importantly is that there is a defect causing damage that could compromise the longevity of a critical part that sees high stresses. I personally would like my 556 rifle to last me a long time, and I'm sure others here would as well.
Serial numbers with known carrier-to-receiver interference:
JS0228XX: Aaron (200 rounds) [mild]
JS023XXX: cufan99 (15 rounds) [mild]
JS0235XX: abrams_34 (800 rounds) [mild]
JS024XXX: dd0s (200 rounds) [moderate]
JS025XXX: bluecollarkid (300 rounds) [mild]
JS0250XX: fun2shoot (800-1000 rounds) [severe]
JS02500X: cheney (800 rounds) [moderate]
JS0255XX: jjksutton (120 rounds) [mild]
JS0259XX: tibim (800 rounds) [moderate]
JS0261XX: 762nato (50 rounds) [moderate]
JS0261XX: paxbnm (90 rounds) [mild]
JS0266XX: Parsley Charlie (200+ rounds) [mild]
JS0267XX: TwiztidKlownzTX (200 rounds) [mild]
JS027XXX: SigOhio (750-800 rounds) [severe]
JS0272XX: aaks38 (350 rounds) [severe]
JS0273XX: KB (cycled manually) [mild]
JS0277XX: 2Loud4You (200+ rounds) [mild]
JS028XXX: rioaguanegra (190 rounds) [mild]
JS028XXX: kylerudibaugh [mild]
JS0286XX: tangodown (hand cycled) [mild]
JS02963X: Mastoo (100 rounds) [moderate]
JS0300XX: Draco556 (1200 rounds) [mild]
JS0307XX: coffey (500 rounds) [Mild]
JS0309XX: hattaresguy (450 rounds) [mild]
JS0313XX: Sapper326 (360 rounds) [moderate]
JS0319XX: San Francisco SIG guy (600 rounds) [minor]
JS0320XX: TexRN (700 rounds) [Moderate]
JS032XXX: bravo5two (400 rounds) [moderate]
JS0332XX: anubismp (~700 rounds) [moderate]
JS034XXX: haiedras (125 rounds [mild]
JS0352XX: mlando (300 rounds) [Mild]
JS0378XX: bubbacop (200 rounds) [mild]
JT0004XX: Sam_SIG (200 rounds) [mild]
JT0012XX: bolt carrier (100 rounds) [moderate]
TP001XXX: EvilBlackGun (65 rounds) [mild]
Below is a list of serial numbers with NO wear or marking on their carrier at all, even though some have a quite high round count. Some have also indicated their upper receiver does not have the “humpâ€
This interference may be causing accuracy issues since it causes the carrier to bind just before coming all the way forward. But more importantly is that there is a defect causing damage that could compromise the longevity of a critical part that sees high stresses. I personally would like my 556 rifle to last me a long time, and I'm sure others here would as well.
Serial numbers with known carrier-to-receiver interference:
JS0228XX: Aaron (200 rounds) [mild]
JS023XXX: cufan99 (15 rounds) [mild]
JS0235XX: abrams_34 (800 rounds) [mild]
JS024XXX: dd0s (200 rounds) [moderate]
JS025XXX: bluecollarkid (300 rounds) [mild]
JS0250XX: fun2shoot (800-1000 rounds) [severe]
JS02500X: cheney (800 rounds) [moderate]
JS0255XX: jjksutton (120 rounds) [mild]
JS0259XX: tibim (800 rounds) [moderate]
JS0261XX: 762nato (50 rounds) [moderate]
JS0261XX: paxbnm (90 rounds) [mild]
JS0266XX: Parsley Charlie (200+ rounds) [mild]
JS0267XX: TwiztidKlownzTX (200 rounds) [mild]
JS027XXX: SigOhio (750-800 rounds) [severe]
JS0272XX: aaks38 (350 rounds) [severe]
JS0273XX: KB (cycled manually) [mild]
JS0277XX: 2Loud4You (200+ rounds) [mild]
JS028XXX: rioaguanegra (190 rounds) [mild]
JS028XXX: kylerudibaugh [mild]
JS0286XX: tangodown (hand cycled) [mild]
JS02963X: Mastoo (100 rounds) [moderate]
JS0300XX: Draco556 (1200 rounds) [mild]
JS0307XX: coffey (500 rounds) [Mild]
JS0309XX: hattaresguy (450 rounds) [mild]
JS0313XX: Sapper326 (360 rounds) [moderate]
JS0319XX: San Francisco SIG guy (600 rounds) [minor]
JS0320XX: TexRN (700 rounds) [Moderate]
JS032XXX: bravo5two (400 rounds) [moderate]
JS0332XX: anubismp (~700 rounds) [moderate]
JS034XXX: haiedras (125 rounds [mild]
JS0352XX: mlando (300 rounds) [Mild]
JS0378XX: bubbacop (200 rounds) [mild]
JT0004XX: Sam_SIG (200 rounds) [mild]
JT0012XX: bolt carrier (100 rounds) [moderate]
TP001XXX: EvilBlackGun (65 rounds) [mild]
Below is a list of serial numbers with NO wear or marking on their carrier at all, even though some have a quite high round count. Some have also indicated their upper receiver does not have the “humpâ€