03-29-2013, 03:36 PM
Looking at the JP carrier, I don't see any additional length on their rails, so I believe you are correct. They must have widened the rails on the carrier. But does a wider rail on the carrier make contact with a wider track in the upper. Basically is the track in the upper wide enough to accommodate or provide benefit to the carrier. I would imagine so or JP wouldn't be touting it. It's kind of tough to see the tracks inside the upper to get a measurement.