9mm accuracy problems
Bullwhip:
Part of your problem could be an unhappy match of powder and bullet to your pistol. Still, I'd tend to believe that bore leading is really at the core of your dilemma. A question: Check your bore. Is there more of a lead build-up.... especially nearer the muzzle end of the barrel?
Most 9mm shooters I know(myself included) have an ongoing battle with barrel leading. In my opinion, a lot of it has to do with the relatively long bearing surface of most brands of 125-grain lead bullets(commercial and self cast), coupled with really inadequate lube grooves(usually only a single shallow one). Even with low to moderate powder charges and hard cast bullets, leading still occurs.
I suppose you could simply switch to shooting jacketed bullets exclusively. Though harder on the wallet, this will solve your problem. Bulk 9mm jacketed bullets are relatively cheap and easily available from a number of sources, including Higginson, Russels and Wholesale Sports, to mention only three.
Another alternative, should you prefer to cast your own, is to invest in a Lee mould for their tumble lube bullet. This slug features multiple lube grooves and may be lubed with their Tumble Lube.
Though leading still does occur depending on alloy softness, this slug works far better than most, for substantially less cost per shot than jacketed bullets. Worth a try, if you know someone who has one of these moulds.
I shoot these using Lyman #2 alloy (9 pounds wheel weight lead to 1 pound 50/50 solder), with pretty good results, using Titewad, Hp-38 and 231(though my gun: S&W 5906 prefers 231) . Leading is far reduced.
Hope this info may be of some use.
Regards: Alex M