I'm at my wit's end trying to get consistency with my HFT 500. I have poor eyesight and historically have struggled to find the best scope to suit my eyes. Add to that some faulty scopes and you can understand why that's what I've tended to blame for large groups - after I'd tried regularly pulling the barrel through (not with wire brushes, just patches). I've tried different air strippers, didn't make much of a difference. My results are worse now than 2 years ago. These days after every competition I shoot a couple of felts through and it reduces the likelihood of severe flyers. However ... I'm using the same model of scope (and the same eyes) on my 20 year old TX200 and my groups are better! Someone said to me they'd improved their consistency when they thoroughly leaded the barrel, at least 500 pellets. So that's what I'm going to try next. My question is this. It seems like an excellent opportunity to use up a variety of half-empty tins of pellets that I've accumulated over the years. For the purpose of generally leading the barrel will it matter if I use a variety of pellets, and if some of them are oxidised? My plan would be to end the process by making the last 100 shots of the current type of pellets I shoot in competition (non-oxidised).