Spitzer solid penetration.

24 April 2003, 18:16

One of the first things we read as big game enthusiasts is when using solids/FMJ they must be roundnose(or flatpoint)only.

How true is the old veering off course/tumbling argument against spitzer and pointed solids?
I know nato FMJ can have unreliable penetration characteristics but will this always hold true for different twists/ bigger calibres etc.

Ron,
Don't suppose you have done any tests with the big spitzers in your 510 versus roundnoses?

Or anyone up to load some Barnes pointy solids in their 375 and try a few feet of phone books or wood blocks for us? [Smile]

Karl.

25 April 2003, 08:19

<Norbert>

quote:

How true is the old veering off course/tumbling argument against spitzer and pointed solids?
I know nato FMJ can have unreliable penetration characteristics but will this always hold true for different twists/ bigger calibres etc.

Solid spitzers in general are unstable in soft media, esp. aquaous tissue, and after travelling a few inches ("narrow channel") they start to tumble. They are not able to generate the stablisising supercavitation effect and therefore lacking good penetration. Twist and caliber doesnï¿½t matter in this issue. Nevertheless they can show devastating wounding effects and killing power. The actual behaviour depends on many factors (material of the target, lenght of the ogive, shape of the nose etc.). In hard materials (plywood) they can go straight because the tumbling is prevented by forces acting on the shank of the bullet. More on stabilisation and penetration of solids: See Penetration Index and SuperPenetrator

25 April 2003, 13:20

Karl

Norbert, I was hoping I would attract one of you guys to the thread. Thanks for the link mate. [Smile]

Karl.

25 April 2003, 17:48

RIP

Karl,
I have put the 700 grain AP milsurp bullets through 3/4" mild steel at 100 yards to 300 yards from my 500 A2 equivalent.

I agree with Norbert. Makes sense to use the pointy solids on hard targets or armor. Flats on flesh.

Of course the 50 grain .223 FMJ tumbles in flesh, making sometimes devastating wounds not in a straight line. Like, into the thorax then out at the elbow.

I will stick with the flat nosed solid for "aqueous" media with bone thrown in, for straight line penetration.

Norbert has a winner, so do GSC and Bridger.
Cheers!

26 April 2003, 03:25

<Axel>

Can someone explain this in terms I better understand? Norbert you mention "supercavitation" what does this translate to with regard to "center of pressure" and "center of gravity". The relationship between the "center of pressure" and the "center of gravity" DIRECTLY effects a bullet's stability in flight.

Axel

26 April 2003, 10:54

<Norbert>

quote:
Originally posted by Axel:
Can someone explain this in terms I better understand? Norbert you mention "supercavitation" what does this translate to with regard to "center of pressure" and "center of gravity". The relationship between the "center of pressure" and the "center of gravity" DIRECTLY effects a bullet's stability in flight.

Axel

In targets 1000fold or more denser than air the conditions are different from those in air. For the supercavitating bullet in aqueous media the center of pressure is perpendicular to the front of the nose (flat point, round nose). On spitzers, when angling a little, the center of pressure is wandering sideways on the ogive, resulting in a lever force, which causes the bullet to tumble. In hard media an additional pressure is also acting on the shank of the bullet when it tends to angle and so it is held on a straight course.
For maximum penetration (armor piercing) of conventional bullets (copper or brass) I use not spitzers as "spitz" as possible, but a very hard, lentil shaped small nose. It penetrates 4" of lead like butter.