I wish I would have had a chance to read this thread a few years ago. I had noticed that I didn't get the accuracy I would expect from my Registered Magnums with modern ammo so I purchased a box of pre-war ammo and did an article in which I tested a 6.5 Registered Magnum versus a Colt .357 Magnum Shooting Master with Pre-War ammo. I only discussed the pre-war ammo in passing but could have included a lot more info after reading this thread. Leroy