Post edited 11:48 pm – February 13, 2012 by Jarhead

There is a difference between wadcutters and semi wadcutters. Wadcutter ammunition is primarily used for target shooting, but some people who worry about over penetration or who can't stand the recoil of a standard velocity or +P load sometimes use Wadcutter ammo for defense. 38 Wadcutters usually weigh 148 grains and the bullet is loaded flush with the top of the case. Most wadcutters are hollow based so some people load them upside down for defensive rounds.

Semi-Wadcutters, which have a flat-pointed conical addition to the Wadcutter design, as well as the sharp shoulder of the Wadcutter is used for target work, hunting and defense. I do not have any idea why, but semi-wadcutter bullets seem to have effects on live targets all out of proportion to their diameter and velocity.

Light bullets (110 to 125 Gr) need velocity to open (mushroom) properly and to be effective. Even with +P+ 38 special you barley meet the velocity needs. The 357 on the other hand has a muzzle velocity of about 1440 fps and a muzzle energy of 583 lbs with the 125 gr HP making it the number one stopping round of all times followed closely by the 110 gr HP. 

Slow rounds need heavy bullets with soft lead and no jackets to impede their expansion.That's why a semi wadcutters made of soft lead are more effective in a slow moving round like the 38 special than the jacketed 125 HP.

As for the 38 specials and the Moros, the army used 158 gr round nose hard cast bullets that didn't expand at all. The full metal jacket 45s didn't either but they were as large of diameter un-expanded as a 38 was expanded and had more weight to boot (230 grs)  The FMJ round nose 45 isn't exactly the last word in stopping power, it was the control expansion  bullets that really brought them into their own.

Muzzle velocity is where your kinetic energy comes from. Double the weight of a bullet and you double the energy, but double the velocity and you quadruple the energy. That's why it's a waste of time going for light bullets in the 38s, unless you are recoil sensitive and looking for a more shootable weapon as opposed to one with more stopping power.

PM97 said

Over penetration is NOT what you want. You do not want your bullet exiting your target. All of the energy needs to be expended IN the target. As far as I'm concerned 1 inch penetration with ALL bullet energy being left in the target is ideal.

While it's true any energy still in a round after complete penetration is wasted, you need as much tissue and organ damage as possible to stop an attacker quickly. The idea is to have as much penetration as possible with out exit. If one inch penetration was enough a hammer would be deadlier than a pistol.

To sum it up terminal ballistic are an interesting but highly technical subject. Books can and have been written on the subject with still no clear answers. There is always going to be the argument….. fast and light vs slow and heavy. I think the truth is either combination is deadly as long as you don't mix them (light and slow), and even that can be deadly at times. Case in point, yesterday my neighbors pit bull got in with my horses and were chasing them. Not wanting to kill him but wanting to teach him a lesson I shot him with a 22 mini cap….a 29 gr bullet at around 710fps . Now this was a big pit bull, but it killed him almost instantly .    

jamie said

The 125 grain had a bit higher Balistic coefficient I was shooting hot loads in 357 mag around 1300 fps

Actually the ballistic coefficient is determined by the length of a bullet vs it's diameter. The longer and skinnier an object is the higher the the coefficient will be. Bullets with a high coefficient not only travel farther they penetrate farther also. Think ball vs spear, the weight may be the same but the spear will penetrate much farther than the ball.