Thank you Straw Hat, thats as good advise as I can give, as I have no load data on hand for it.
Keep in mind that the OWC was designed to be a supersonic bullet too. In other words, it will fly accurate at supersonic speeds whereas bullets with straight sides and flat nose will not. I will recommend that you try Hodgen Universal clays with any data for swaged lead commercial bullets as are produced by Speer and Hornady, including their wadcutters, roundnose or SWC offerings. All will be very safe charges even if weight is far different. The object here is to get a ballpark for the velocity you desire. For the softest report, if that's a concern, the load must be subsonic, which is under 1100 fps, or even 1000 if you are working the load up in cool or cold weather, as speed will increase quite dramatically at high temperatures. If you don't have a chronograph, you can load a cylinderfull of several loads and take them to a wooded area for accuracy testing. Choose the most accurate of the lot, and if the heavier loads produce a pronounced sharp crack as they go past the trees, your load is supersonic.
That bullet will 'splinter' varmints with supersonic loads! But it will also anchor varmints up to coyotes in their tracks with decent bullet placement even at velocities down to 800 fps.