I run 1.265" 200gr SWC through my SR1911 regularly with great success. Actually, 1.267-1.268". What problems do you typically see with this length SWC cartridge, and which firearms are more likely to see this problem?
I set my seating die for a commercial cast ersatz "#68" cast SWC to headspace on the bullet shoulder in a Wilson barrel, as shown in the color diagram regularly reposted here. It was 1.245" OAL and I did not find it necessary to change for other guns. But I don't have a Ruger.