I have a bunch of 30cal 147gr tracer pulls from M25 30-06 cartridges that I load up every now and then in my 308 and 300BLK. The problem is that they are really expensive for a crappy bullet and the 30cal ones don't usually light up till they are past 100 yards which not so useful unless you are lobbing them across a field which isn't exactly safe usually. The novelty wears off quickly in a semi auto. Fun for the first 20 then you'd rather have something that is more consistent accuracy-wise.