A precision-obsessed friend was lamenting the apparent inability of his Robinson XCR to shoot tight groups. Although it was not designed specifically for precision, I am a fan of the gun’s design. Particularly given its ease of changing barrels, I began to wonder how much we could improve on the standard chrome-lined light-contour barrels. So I sent two Lothar-Walther match-grade 1:8 rifled stainless steel blanks to Robinson and waited (seven months) for them to return as heavy-contour 11″ 5.56mm XCR barrels.
This is not a gun that is easy to shoot precisely: It is light, and its single-stage trigger breaks at over 4 pounds, which I know robs me of accuracy. In order to remove shooter dispersion from the equation I tested various configurations in a custom machine rest. I ran a range of ammunition through two standard 11″ barrels and, sure enough, 10-round groups would typically exhibit a mean radius in the vicinity of 1.5MOA. The standard 16″ light barrel, interestingly, printed 10-round groups with MR just above 1.0MOA shooting light bullets (both XM-193 and Wolf Classic!), but didn’t do as well with heavier bullets in match-grade loads (despite its 1:9 twist).
With the new precision barrels the rifle prints 10-round groups with mean radius consistently below 1.0MOA, like these:
Note that from the short barrel 75gr .223 loads run about 2260fps. On the high end, 55gr 5.56mm clocked 2775fps.
There is some vertical stringing evident, which varies with the upper, and which suggests there is further room to tighten the design. And, as mentioned above, these groups were achieved with a machine rest. When I shoot off of bags 10-round groups open up by roughly another 0.5MOA. Suffice it to say that with a good barrel and shooter this gun is capable of respectable accuracy.