…
I’ll look and see what I might have for pistol ball in gelatin, but they’re pretty boring. They all make a hole the size of the bullet, usually all the way through the block.
I was under the impression thsat the actual crush channel was sub caliber due to bullet profile and tissue stretch.
You’re right, though obviously the projectile does make a hole the size of the bullet before the gelatin stretches back. Point to the OP, is that’s all you get with FMJ’s at pistol velocities.
…
That was AK’s link, but I will keep looking for a good pic of a gelatin shot with ball. I know I have some.
Duncan MacPherson determined the size of the permanent crush cavity left by bullets at hundgun velocities to be direct functions of the shape, and diameter of the bullet.
MacPherson’s bullet shape factor for the following bullet shape configurations (p. 205):
.43 Sphere
.69 Round Nose
1.00 Cylinder
.66 Truncated Cone
.66 Semi-wadcutter
.63 45-degree half angle cone
.82 JHP
Permanent cavity diameter = (Shape factor) X (bullet diameter).
This is why JHPs are best regardless of caliber. Not only will a JHP have a larger diameter, but it also has a larger shape factor coefficient leading to much more crushed tissue.
If folks are really concerned about penetration through barriers then a bonded bullet will be the best option.
In this day and age of modern robustly expanding hollowpoints in both bonded, and unbonded versions I see carrying ball (when not limited by law) as introducing a foolish handicap into an already crappy situation.
Carrying ball ammo in service caliber handguns for defensive use is just retarded as hell.
You get less “stopping power” (I know, but you know what I mean), a much greater chance of a dangerous shoot through on the bad guy, and a much higher level of potential ricochet by using FMJ ammo.
Mainly I would guess guys do this because most cops are basically cheap as hell and don’t want to spend the money and/or effort to find the right ammo.
That being said, only having one approved type of ammo is also a bad idea.
When I re-wrote our ammo policy I added approved types of ammo to what the officers could carry in off duty guns or BUGs. Last year was a good example of worst case scenario as to why (even now things ain’t great).
We issue the 124gr +P Gold Dot here for our 9mms, but we allow a wide variety of approved pistols and revolvers for off-duty and BUGs. Even in 9mm our officers would have a hard time finding the 124gr +P Gold Dot for personal use if we mandated such, same-same for other calibers.
At one point my whole agency had to switch approved ammo due to the 124gr +P GD being back ordered for more than a year. We found a vendor that could deliver the 124gr +P Ranger-T immediately, so I did the paperwork to approve that ammo for on duty use.
If we had mandated one type of ammo, and only that ammo, then the whole agency would have been out of luck that year.
On our approved list I basically approved Doc’s suggested duty ammo list with a couple of additions for the smaller calibers in the BUG type guns (we allow .32s and .380s as an example).
This gives the troops a chance to find something that is available, and hopefully is accurate and reliable in their guns.
Maybe the only time ball ammo could be considered a “good” choice, would be in the sub calibers, (.25, .32, .380). Many of the hollow points in those calibers will fail to penetrate deeply enough. All the IWBA guys that I knew took that position, that it was better to at least get the penetration. I’ve occasionally carried mouse guns, and I put ball in them.
What’s funny, is that I know of agencies that switched from Ranger to other brands because they couldn’t get it. I think some ammo distributors got better deliveries than others, or they picked and chose who got what and when. The last few years were an anomaly, with everyone buying more ammo than they ever had before, both public and LE, and none of the companies were able to keep up. From the amount of ammo I saw at Wal Mart and at the gun show, I think those days are just about over.
Maybe the only time ball ammo could be considered a “good” choice, would be in the sub calibers, (.25, .32, .380). Many of the hollow points in those calibers will fail to penetrate deeply enough. All the IWBA guys that I knew took that position, that it was better to at least get the penetration. I’ve occasionally carried mouse guns, and I put ball in them.
I normally recommend FMJ when it comes to the tiny guns, for the same reason.
Added benefit is that it will feed better… something the hollow points in .32 and .380 don’t always do well…
With that in mind, what’s up with MacPherson’s shape factor being .69 for round nose FMJ but only .66 for truncated cone FMJ? We’ve all heard folks say they carry flat point FMJ in their BUGs since it presents a sharper edge and flat face to hopefully crush a larger amount of tissue ahead of it than a more piercing/stretching effect of a round nose. The logic seems reasonable. Does anyone know how he determined round nose actually crushes a small bit more than a flat point?
One thing is a sharp and hard bullet with a large metplat in proportion to its diameter (a full wadcutter, or a LWN design in a large caliber), and another a normal TC design (specially for autos) where the metplat is not very large and has rounded edges. Perhaps McPherson was talking about this last case.
0.69 to 0.66 is only a 4.5% increase… I would not loose any sleep over it.
Perhaps, I am picking nits, but, when comparing bullet sizes, one must compare cross-section area, not diameter.
Divide 0.66 by 2, square the result and multiply by pi to get 0.342
Divide 0.69 by 2, square the result and multiply by pi to get 0.374
Therefore, going from 0.66 diameter to 0.69 is a 9.4% increase, which is still small but non-trivial.
Yeah, I know–picky, picky, picky!
Velveteenmole has a good question though. Why would even a TC, have a lower number than a RN?
When Macpherson refers to truncated cone he is talking about bullets that look like this.
The actual meplat of the bullet is very small, and the sloping shoulders lack any sharp edges. The result is reduced wound trauma compared to a round nosed projectile which is blunt, and provides more resistance.
True WFN, large meplat bullets tend to behave like cylinders that are the diameter of the meplat. Keith style bullets behave similarly.
I recall an experiment done where a Keith bullet was marked with a sharpie, and fired into a test media. The marker on the shoulder of the bullet was not rubbed off indicating that during penetration the shoulder did not make contact with the media.
BuckskinJoe, you are right about the area being 9.3% larger… still a very small difference to me. And of course, since we are happily including decimals in our calculations we must remember those are only estimates, the actual number varies with the specific design of the bullet point/ogive.
For example, one thing is a fairly blunt “round nose” like the 45 and 380, and another the typical 9 mm ogive, commonly named round nose too.
I remember when the Air Force was doing their ammunition testing back in the 80’s and had given the TC 9mm bullets such high scores compared to RN FMJ’s. I don’t know the efficacy of their testing protocols, but it always seemed to make sense to me. iirc, the Hornady TC .45’s and 9’s were developed in conjunction with that testing.
The flat meplat pushes tissue radially away from the ogive and shank, creating a small temporary cavity.
According to MacPherson an unexpanded JHP bullet has the same shape factor (.66) as a TC bullet.
I suspect the blunter meplat of a RN bullet contacts and crushes tissues before the tissues have the chance to stretch and “flow” around the elliptical ogive, which might explain why the RN has a greater shape factor than a bullet with a simple conical nose.
In addition to the pointy meplat, a conical bullet probably propels tissues radially outward more efficiently than the round nose’s elliptical ogive contours. Finally surface area of a conical ogive is less than the surface area of a elliptical round nose.
More and more modern missile designs use a nose fairing with a conical nose cap, which appears to reduce aerodynamic resistance and increase velocity and range (e.g., the Peacekeeper missile, Space Shuttle solid rocket boosters, and I’ve seen experimental conic-elliptical nose fairings on MRLS rockets). I’ve wondered if a bi-conic or a conic-elliptical ogive on a long rifle bullet might allow it to penetrate the atmosphere more efficiently than a a common elliptical ogive.
This data was published in the December 1974 and June 1975 FBI Law Enforcement Bulletin. It does provide a comparision on the behavior of non expanding handgun bullets while penetrating the test media.
[b]Comparison of the Wounding Effects of Commercially Available Handgun Ammunition Suitable for Police Use
Southwestern Institute of Forensic Sciences
Dallas Texas[/b]
Energy lost when fired through 20% gelatin blocks 10 degrees C
Blocks 16cm Height 16cm width 15cm depth
Service Automatics: muzzle velocity fps…energy lost ft lbs
9mm winchester 115fmj-rn…1132…107
9mm remington 124fmj-rn…1108…110
9mm s&w 115fmj-swc…1160…176
9mm remington 115jhp…1196…330
45acp remington 230fmj-rn…812…117
Service Revolver: muzzle velocity fps…energy lost ft lbs
38spec remingtom 158rnl…789…72
38spec winchester 158swc…930…136
38spec western 150mt*…972…136
Small Automatics: muzzle velocity fps…energy lost ft lbs
380acp winchester 95fmj…866…74
32 acp remington 71fmj…912…66
25 acp remington 50fmj…774…47
22 lr winchester 40rnl…955…67
*conical metal tip/metal piercing