Originally Posted by
405grain
Possibly for long range target shooting velocity may be an important criteria, but for hunting and general target shooting it isn't the most important aspect. Jacketed bullets have a hard copper jacket that requires higher velocity and impact energy to expand than cast bullets. Because cast bullets don't have a hard metal jacket, they expand at lower velocities. The higher velocities of jacketed bullets would probably be a determent to cast bullets when hunting because it might cause the bullets to fragment on impact instead of penetrating deeply and expanding normally. As a lucky coincidence, the velocity range where cast bullets are best at penetration and expansion on game is usually around the same region where best cast bullet accuracy is obtained.
High velocity, sometimes not even up to jacketed velocity, can cause cast bullets to become inaccurate. There are lots of reasons for this: deformation because of acceleration and pressure, too high of a spin rate, gas cutting and blow-by from excessive pressure, etc. To get accuracy at high velocity you really have to work for it. With specialty alloys, advanced reloading techniques, and firearms designed specifically for shooting high velocity cast loads, if you have the skills you may reap the benefits of those higher velocity loadings. But for the vast majority of us casters, we get out optimal accuracy at a lower speed range. Case in point: my 6.5x55 Mauser is capable of shooting a 3/4" group at 50 yards with a 150 grain Lyman #266673 using a charge of 14 grains of 2400. That's "only" around 1500 fps. If I chose a higher velocity those groups would start to open up. Another example would be my 7x57 Mauser, shooting an RCBS 168 grain bullet with 28 grains of IMR-3031 (with 1 grain poly filler), that has been able to print 1" groups at 100 yards. (scope, benchrest, no wind, me doing a decent job, etc.) This is at around 1750 fps.
I don't want to push a bullet faster just to try and emulate jacked bullets. Cast bullets preform at a different design regime. I would have no qualms using that same 7x57 target load to hunt with, though if I were loading specifically for hunting I'd probably step up the velocity to 1850 fps. For both general target shooting and hunting, cast bullets loads below 2000 fps are usually the best choice, and going higher can sometimes put you at a disadvantage rather than an improvement.