Is it the weight?

[Chuck Whitlock]

This was spurred by something tpd223 mentioned in this thread:

http://pistol-forum.com/showthread.p...d&p=167447#top

As a general rule from Doc Roberts's testing results, heavier projectiles seem to have better terminal performance than lighter ones, caliber for caliber. 55 v. 75-77 grain in .223/5.56, 115 v. 124-147 in 9mm, etc.
The all copper Barnes bullets seem to throw a monkey wrench into the conventional wisdom, with the lighter bullets having performance characteristics more on par with the heavier conventional offerings.

So, given similar bullet construction (jacketed lead, say), is the enhanced performance of the heavier bullet actually a function of the weight itself? Or is it more a function of the length, or perhaps sectional density, relative to the bullet diameter?

I am interested in your thoughts/observations.

[John Hearne]

So, given similar bullet construction (jacketed lead, say), is the enhanced performance of the heavier bullet actually a function of the weight itself? Or is it more a function of the length, or perhaps sectional density, relative to the bullet diameter?

I'm not Doc but I'll take a shot. The general characteristic of Doc's good load is that they offer decent to deep penetration. Especially with pistol bullets, projectile weight is ping to be associated/correlated with weight. Since sectional density is computed with projectile weight, rounds with this characteristic will tend to match Doc's criteria. Although I don't think Doc likes it as much, I like to look at momentum as a good predictor and it is tied to weight as well.

Bullet diameter enters into the equation as the easiest way to add potential weight to a projectile (while keeping it short enough to fit in a pistol magazine) is to make it bigger. Bullet diameter effectively buys you payload - there simply aren't any 230 grain 9x19mm projectiles. In fairness, sectional density can negate some of this advantage as you select the heavier loads.

[BLR]

This was spurred by something tpd223 mentioned in this thread:

http://pistol-forum.com/showthread.p...d&p=167447#top

As a general rule from Doc Roberts's testing results, heavier projectiles seem to have better terminal performance than lighter ones, caliber for caliber. 55 v. 75-77 grain in .223/5.56, 115 v. 124-147 in 9mm, etc.
The all copper Barnes bullets seem to throw a monkey wrench into the conventional wisdom, with the lighter bullets having performance characteristics more on par with the heavier conventional offerings.

So, given similar bullet construction (jacketed lead, say), is the enhanced performance of the heavier bullet actually a function of the weight itself? Or is it more a function of the length, or perhaps sectional density, relative to the bullet diameter?

I am interested in your thoughts/observations.

Ballistic, especially terminal ballistics, cannot be distilled to bullet weight or sectional density. Loose correlations are there though.

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[Rich]

its all about the design of the bullet like BH 50gr TSX vs 75gr TAP or BH 50gr TSX vs 55gr soft points

also see 124gr 9mm +P compare pretty well with 147

[Chuck Whitlock]

Loose correlations are there though.

This is where this thought train is going.

[buckskinjoe]

A toaster is far heavier than anything mentioned, so far. Does that make it a better projectile?
Folks get sidetracked with red herrings ("Is it the weight?" for example) instead of studying well-settled science of terminal ballistics.

[Chuck Haggard]

A toaster is far heavier than anything mentioned, so far. Does that make it a better projectile?
Folks get sidetracked with red herrings ("Is it the weight?" for example) instead of studying well-settled science of terminal ballistics.

Yes, but a toaster is mostly hollow thus would have poor sectional density, and would likely fragment and fail to penetrate when driven at high velocity.

See? Construction and sectional density both figure into the picture.

[TCinVA]

Now I really want to see the results of a toaster shot in ballistics gel.

[Alaskapopo]

Heavier bullets have more bullet to expand. Generally heavier bullets can be made to larger diameters and they damage more tissue in this matter they also penetrate more than a lighter bullet because of the momentum. Of course there is a point of diminishing returns and even negative performance once you get a bullet so large you can not put enough powder into the case and be with in safe pressures for the cartridge. (ie 200 grain 38 special bullet)

[WDW]

Now I really want to see the results of a toaster shot in ballistics gel.

I know a guy with a cannon....