AR Sponsor
Posted: 8/17/2016 9:10:04 PM EDT
| I have been pondering this for awhile and can't seem to grasp it. A bolt carrier is steel, a upper receiver is generally aluminum. How does the upper last thousands of cycles? I thought the carrier would chew the upper up since its a lot harder. |
|
It is not a tight fit by any means. The bolt carrier essentially "floats" in the upper. Combine that with the hard anodizing layer on the Al receiver and proper lubrication, and so long as everything is in spec there is little by way of wear points between the two surfaces. Most of the impact forces are on the bolt and the front face of the carrier, both of which interface with the hardened steel of the barrel extension. |
AR Sponsor