Alliant doesn't list any loads for Reloder 10x, but Alliant's online data is crazy to navigate. However, the linked data at 204ruger.com shows a starting load of 21.6 for the 39 grain Sierra. So, we fall back on the old rule that you can step down in bullet weight with the starting load and keep pressures safe, and yeah, a 22.0 grain starting load might be okay with a 34 grain bullet. Go slow, watch for pressure, and do all the other safe stuff. Be careful.
If you wait a while before you start, maybe someone with QuickLoad will chime in.