Shooting DTACs in a 6 XC was the reason I went to the SLR. The XC , in my opinion, was optimized for XC shooting with bullets from 70 thru the 105-107 class of bullets. That is the purpose for which Tubb designed it. It made use of the heavier bullets for +300 yd shooting. All that said, shooting 115 gr bullets in the XC is doable, but in order to get them up to a speed where they showcase their BC advantage over the 105s, pressures run high at the expense of brass life. Yes I know the 1K records Tubb shot with it, but no one asked him about the life of his brass or the special throating he used to do it.
There is not enough boiler room in the XC to produce the velocity needed to exploit the BC advantage of the DTAC. Primer pockets don’t last long when u push heavy bullets at 3100 fps in the XC, even with long bbls. My bbls ran 30-32 inches.
A 243 based case will easily run 3150+ with a 115, but it will also take a 105 up in the 3300+ zone. Lapua 243 brass lasts a long time in that performance range.
I think the XC is a great cartridge, so much so, that it was copied n called a 6 Creedmore. Just don’t ask it do perform outside of its designed range n not expect some negative results.
