HP vs FMJ vs SP?

[A.M.]

Another question!

Sorry for all the questions but since I'm new to this rifle world I feel like I get more confused as I learn things: 1 step forward, two steps back!

So, obviously, with handguns, a hollow point bullet acts MUCH differently than a FMJ... But the area that is hollowed in it is large.

Looking at the 7.62 rounds, the hollow area looks like a mouse took a drill and ever so gently removed a needle sized amount from the tip.

Does this actually affect the round? Does it make a difference?

Or, in practice, does the FMJ act essentially the same as a HP?

[Lugiahua]

I was thinking about it too
how much difference does JSP/JHP make against soft target from a rifle? is there a significant advantage using them against bad guys?

[bsumoba]

i have heard that if you're going to hunt, especially a 7.62x39 round to get SP. SP's seem to expand very nicely on a soft/hard target.

from my experience, my AK doesn't like HP as much as the SP and FMJ, so i stick with what works. with that said, i still have HP in my ammo can also.

[21SF]

http://en.wikipedia.org/wiki/Hollow-point_bullet

Expansion

When a hollow-point hunting bullet strikes a soft target, the pressure created in the pit forces the material (usually lead) around the inside edge to expand outwards, increasing the axial diameter of the projectile as it passes through. This process is commonly referred to as mushrooming, because the resulting shape, a widened, rounded nose on top of a cylindrical base, typically resembles a mushroom.

The greater frontal surface area of the expanded bullet limits its depth of penetration into the target, and causes more extensive tissue damage along the wound path. Many hollow-point bullets, especially those intended for use at high velocity in centerfire rifles, are jacketed, i.e. a portion of the lead-cored bullet is wrapped in a thin layer of harder metal, such as copper or mild steel. This jacket provides additional strength to the bullet, and can help prevent it from leaving deposits of lead inside the bore. In controlled expansion bullets, the jacket and other internal design characteristics help to prevent the bullet from breaking apart; a fragmented bullet will not penetrate as far.
Accuracy
A fired .38 Special hollow-point bullet viewed from the side, showing the intended terminal ballistics sometimes referred to as mushrooming.
An expanded 124 grain 9mm jacketed hollow-point.

Where target shooting accuracy is the prime consideration, some bullets such as the Sierra "Matchking" incorporate a cavity in the nose section. This has the effect of lightening the bullet's forward section and shifting the center of mass towards the tail of the bullet, to give an improved ballistic coefficient, greater down-range velocity retention, and greater resistance to deflection by crosswinds. The manufacturing process of hollow-point bullets also produces a flat, uniformly-shaped base on the bullet which increases accuracy by providing a more consistent piston surface for the expanding gases of the cartridge.

Match or target hollow-point bullets are designed for precision target use, and no consideration is given to their expansion or other terminal ballistic performance. The United States military, for example, uses hollow-point bullets in some sniper rifles for their exceptional accuracy at long ranges, and believes that the hollow-point does not result in wounds significantly different from full metal jacket ammunition in practice.[2] Some hunters, however, have reported good expansion characteristics and quick, "humane kills"[citation needed] from hollow-point target bullets

[A.M.]

Thanks for the info, however my question relates to practice not theory. I 100% get that the depression causes mushrooming. My question is that when you have a hole with a mm or less in diameter moving that fast, does it actually mushroom or does it just fly through.

[shooterbill]

There are different kinds of hollow points. Varmint style hollow points are usually large and have a thin jacket for rapid expansion. Match bullets were not designed to expand. They are being shot at paper or steel. FMJ's do not expand on soft targets and pass through without much visible damage. FMJ's will kill and make soft targets come apart.

[Laythor]

yes, a hole that small will mushroom when coming in contact with something more solid then air.

http://www.youtube.com/watch?v=kGrq1oP37LI

[A.M.]

So soft point or hollow point?

Ugh.

[21SF]

If your trying to kill someone anything will work, SP will hold a edge in wound damage.

Plinking? it doesnt matter, whatever is cheaper.