Middle Age Russ,Middle Age Russ wrote:Wad-cutters are almost always made of very soft lead and have a hollow base. Being very soft lead, velocities and energy of wad-cutter loads must be modest to prevent severe lead fouling. The deform but don't really expand and penetrate reasonably well.
Before the advent of jacketed hollow point pistol bullets, people used dum-dum rounds (a hollow-base wad-cutter bullet loaded backward) to help produce a bit of expansion from low velocity cartridges. The typical soft lead round-nose loads were somewhat better penetrators than wad-cutters due to the nose design, and would deform a bit but seldom expand at all. Dum-dum rounds offered modest expansion at best and were simply a small step up the performance ladder from the lead round nose loads.
Over the last 30-40 years, a great deal has been learned about producing projectiles that expand to limit penetration. Modern loads with controlled-expansion bonded, jacketed hollow points offer far superior and predictable performance -- expanding quite consistently to enlarge frontal area and limit penetration. There are several reduced recoil loads being produced with such modern projectiles if the reduced recoil is desired.
I agree that there have been substantial changes made in bullet design and manufacture during the last few years. However, I've checked every ballistic gelatin test and Clear Gel test I can find on the internet and quite a few of those fairly new designs sometimes over or underpenetrate and many times they don't expand. Actually, expansion is not one of the criteria I place too much importance on: I believe that practical accuracy (which depends more on me) and sufficient penetration are the most important factors in a self-defense situation.
Thanks for your help,