Hi, I have a 30-30 lever action that I'm trying to work up some loads for. This is my first lever action that I'm developing a load for and I have been seeing some stuff that I really haven't seen before and I was wondering if someone could help me understand whats going on. Basically I have been playing around with remington core-lokts RN, 150gr & 170gr, along with IMR4895 and IMR3031, and a Federal 210 primer. Here's what I've been seeing: 1. I noticed that .5gr difference would sometimes shrink a group considerably, but another .5gr opens it right back up. For example, 29gr. of powder gives 3" group, but 29.5gr gives 1", then 30gr gives a 3" group. 2. Another thing I noticed is that when I get a good group, I try to replicate that load for my next range session, only to have the group open up. 3. The last thing I noticed is that when I would replicate a load, the POI would shift a few inches even though the rifle hasn't been touched. I've seen some of these things happen before, but not as frequently as I am now, and I was wondering if anyone has some insight or general explanation as to why these things occur and what it could mean. What do you suggest my next steps be? Should I try another powder? Change bullets? or both? Thanks!