I know a number of folks use LP primers in their 45/70 BP loads. Thought I would try some loads with LP primers with smokeless loads. I loaded up some rounds with my general purpose load of 24gr of 2400 under a Lyman 457193 and substituted a CCI 300 for the CCI 200 I normally use. Mainly wanted to see how the LP primers would work as I have a lot more of them than LR. Well, there was no appreciable difference that could be detected on the targets. Groups on paper at 100 printed the same place and if anything the groups fired with LP primers were a bit tighter. I adjusted the sights for 200 yards (based on LR fired loads) and again found no difference in POI. Well centered hits on 12" steel with both. No pierced primers or other problems though I would not use LP for T-Rex loads, but I have no use for those anyway. Hope this may be useful given the current component situation.