Carrier dragging

[Artiz]

Hi, just a quick question, I noticed the rear bottom of my carrier is pretty shiny from dragging in the receiver extension (mil-spec Armalite) which appears to be uneven inside, the draggin marks appear to be on raised portions of the machining marks, I've not put a lot of rounds trough it yet, I've only hand cycled it a bit to work the trigger, but I'm just wondering if you guys have seen the same thing or maybe my RE is the guilty part, I don't know.

Complete LMT 14.5" upper over home assembled RRA lower with Armalite mil-spec RE.

Thanks a lot.

[eternal24k]

Assuming these machining marks are not very obtrusive, I would just shoot it. It will most likely smooth out over time, and so long as it works it should be fine.

None of my carriers have wear there, because that is usually a piston wear point from carrier tilt, but since you mentioned seeing the points that are touching I wouldn't worry about anything weird happening.

[Artiz]

I'm not worried about any functional or reliability issues, it's not DRAGGING like the word would imply, it's just that the carrier obviously can wobble around and touch up the slightly raised portions of the RE machining when hand cycled, next time I shoot it (won't be shot for a while, sadly :() I'll put some sharpie on the wear spot, which is on the ejection port side of the buffer retainer cutout, and see if it touches the RE, I bet it won't.

It cycles smooth even if the RE is pretty rough inside, so it's all good. :p

[rattlesnake]

I've noticed the buffertubes made in China (leapers/utg) are pretty darn rough inside. Not saying Yours is made in China, just stating my observations. The new utgs are supposidly made in USA. I got to compare the "made in usa" and the old made in China buffer tubes and the Made in China ones seemed alot rougher on the inside. This was at a gunshow. I've never personally ran a utg buffertube, so I'm not sure if the roughness will cause wear.

[Eric D.]

If you noticed it after hand cycling this is what's happening. The CH grabs the gas key, above the center of mass of the carrier. This offset is producing a moment or torque that is also found on piston ARs. During operation the gas pressure impinges upon the BCG in-line with its cent of mass, therefore no moment. The RE will wear LONG before you carrier does. Keep it lubed and don't be hand cycling it thousands of times :laugh: