In my M94, plain based designs worked just fine with a hard card under the bullet. Due to the reduced speed of the short case, even when loaded 'plain' they can shoot very well.

If the bullet is larger than the groove diameter by .001" or .002" and of appropriate hardness, leading is not a problem until well over 2,000fps - normally, when using decent lube. I mostly used LBT Blue, but added some Vaseline to soften it a bit to help it flow in my sizer. Just make sure you don't overhead any lube as that will injure it's lubricity.