RFI, soft points vs FMJ on steel, what gives?

[ViniVidivici]

What is this madness?

So, I've loaded some 62gr soft points (unknown manufacturer, they're pulls from American Reloading), shot some at 100 yards, and they're cratering the steel!



This is what my 62gr FMJ looks like, same 100 yards.



Same charge of 24.4gr H335, same mixed brass. I would have thought the SPs would do LESS damage to the plate, not more!

Yes, I did check these with a magnet.

What gives? It looks like they're being hit with m855!

[C-grunt]

Maybe the lead in the soft point is harder than the lead in the FMJ?

[ViniVidivici]

Yeah, that's all I could come up with. Just seems strange that it'd be that way.

I mean, I've shot FMJ at that thing within 40-50 yards, and not dinged it like that.

[hi-wayman]

Have you run both loads over a chronological? I thought it was velocity that cratered steel. Could be that the different bullets vary enough in construction/hardness to give a velocity bump.

[ViniVidivici]

No, no chrono available, but I can't imagine the slight difference in velocity due to a harder bullet getting slightly tighter neck tension would make enough difference to see what I'm seeing.

I would think it'd have to be 200-300 fps faster to make that kind of difference.

[markm]

Damn. That looks like 55gr FMJ pocking. Interesting.

[Alpha-17]

I've heard of this phenomenon before, as well as similar pitting with ballistic tip ammo. Not a clue of the physics behind it.

[markm]

I've heard of this phenomenon before, as well as similar pitting with ballistic tip ammo. Not a clue of the physics behind it.

Some sort of "shape charge" effect.

[lysander]

Velocity = penetration

What type of steel?

[ViniVidivici]

Allen Co., AR500, 3/8", this is a 12"x20" silhouette, bought at the LGS in town.