I have installed hundreds of Shilen barrels over the last 40 years and have always been happy with them. When I started gunsmithing, the most popular aftermarket barrels were from Shilen or Douglas. Both were and are excellent barrels.
I have re-contoureda ton of Shilen barrels and have never has one warp or change measurably. The same goes for those I have machined octagon or half octagon; no apparent distortion and they shot well. GD