I have had the most consistant load development with my custom rifles.With high quality barrels and precision chambering and bedding,they shoot well with most loads,although like all gunsthey do have favorites.The only real exception was the swift scirocco bullet that hasn't shot well for me in any cartridge,or any rifle.The most difficult to load for were some factory rifles that had bedding flaws or poor bolt lug contact.They were very fussy and small changes in loads produced large variations in accuracy.Again,I see thequality of the gun being far more important than the cartridge.