So to install a Magpul UBR on an AR-10 carbine you must convert your buffer/spring system to something loosely AR-15 compatible as that’s what the UBR’s designed for. So I ordered Slash’s CAR-10 XH Buffer and spring from http://www.heavybuffers.com. The communication was smooth and the shipping very prompt. When received, the packaging could have used some additional inspiration, but the buffer is a hunk of steel and tungsten so it’s all good. Here the plastic bag was inside the USPS envelop which had broken open, I didn’t rip it apart. The envelope was then inside the box which was undamaged in shipping:
The product was undamaged. Here’s some shots of the head stamp and spring:
…also note that the spring appears to be an AR-10 spring that was crudely cut. I suspect it’ll work but I think I’ll turn back the sharp point at the end to avoid damaging the UBR tube. I probably would not buy the spring again.
More on its performance later.