A little further reading from Ammo Oracle…
Unlike most FMJ rounds, M193 and M855’s primary wounding mechanism is fragmentation. This is a good thing because without fragmentation these rounds otherwise would act like a ice pick and cause very little damage because of their small size.
Q. Does the 2,700 fps rule apply to all .223 and 5.56 ammo?
No.
Velocity is only one factor, however important. Bullet construction is another. M193 and M855 fragment because the bullets have thin copper (actually “gilding metal,” which is a copper alloy of roughly 90% copper and 10% zinc) jackets that are further weakened by a cannelure. It cannot be assumed that all bullets will fragment, or will fragment at the same velocity.
Many people wrongly assume that any ammo loaded with a 55gr FMJ bullet is the same as M193 ammo. This is false. Unless the ammo meets M193 specs, including both muzzle velocity and bullet construction, it can not be counted on to perform like M193.
So again I ask…if I can’t get military ammo, whose FMJ round should I buy?
Again from Ammo Oracle…
Q. What is “Ballistic Tip” ammo?
“Ballistic Tip” is actually a trademark of Nosler, who first started making plastic tipped bullets in 1985.
Though originally designed to prevent damage to the bullet nose when feeding (while the nose of a soft tip or hollow point might deform due during feeding to the soft lead content in the nose, a plastic tip bullet will maintain a consistent nose shape) today the primary advantage of a polymer tipped bullets is a high ballistic coefficient. The design also allows the center of gravity to be moved back, increasing in flight stability. This is the same design theory that gives hollow point match bullets better accuracy properties.
In terminal performance, ballistic tips are designed to work like wedges, mashed into the hollow point and inside the jacket on impact, initiating expansion theoretically, quickly and reliably.
Q. Is military ammo the best choice for defensive use?
M193 is probably the best choice for an all-around ammo selection, given its low price, wide availability, and the ability to be stabilized from any 5.56 rifle. For military-type operations, M193 should comprise the bulk of your 5.56mm ammo. However, other types of ammo may be better for a specific application, such as home defense or police work, or when using a 5.56mm gun with a very short barrel or when velocity is likely to be low.
For police-type work where a soft-point is desired, Winchester’s 64 grain PowerPoint (in the Super-X line) and PowerPoint Plus (Supreme line) are top performers.* It has the advantage of being less sensitive to velocity by relying on bullet expansion rather than fragmentation, and is more consistent over a longer range of velocities. It would also be a better choice for use in AR-type pistols and short-barreled rifles, where the short barrels impart much lower velocities on the bullets. The downsides of this round are: questionable stability in 1:12-twist rifles, a smaller wound channel compared to a fragmenting bullet, and a cost of 3-4 times as much as M193.
Q. But what about specialty commercial rounds, like TAP, hollowpoints, and softpoints? Aren’t they better than Mil-Spec ammo for defensive use?
It really depends what you are looking for. In general Soft Point, Jacketed Soft Point and Jacketed HollowPoint rounds use controlled expansion as a wounding mechanism, rather than fragmentation. The yawing effect of FMJ bullets is frustrated by JSP and JHP rounds because the nose flattens down on impact (like a mushroom) and moves the center of gravity forward on the bullet. As a result, the bullet doesn’t yaw, but instead gets its stability from the transfer of the center of gravity. Generally these rounds continue forward in tissue nose-first instead of trying to turn tail-first.
Some very light JSP or JHP rounds will still fragment because their jackets are so thin and their velocity is much higher (up to 3800 fps in 40gr rounds), but this does not necessarily make their wounding capacity more dramatic than M193 or M855 primarily because their penetration depth is much lower.
Hollow-point and ballistic-tip bullets are designed as varmint rounds, to expand quickly, making large, shallow wounds with relatively little penetration. These types of wounds aren’t likely to take an attacker out of the fight immediately, especially if you have to shoot through an arm or from the side. Most experts agree that at least 12 inches of penetration is required to reliably reach the vital organs, and most varmint bullets won’t penetrate more than 5 to 6 inches. Although some police departments use the Hornady TAP (“Tactical Application Police”) round, which is merely a hotter-loaded V-Max varmint round, the primary motivation for adopting this ammo is preventing over-penetration of both bad guys and of interior walls. It should be noted that many of these concerns are proving unfounded as testing on interior penetration is increasingly showing that 5.56 rounds are less of a overpenetration risk than even the 9mm handgun ammo that many departments deploy in submachineguns for interior raids.
The above passage seems to say that not only are HP’s and the V-max perhaps not the best choice, neither is the TAP round. My LEO friends seem to think the TAP round is the greatest thing since free donuts.
To wrap this up (at least for tonight)… I have a small supply (~650 rounds) of American Eagle 50gr flat base HP’s. I thought they would be an effective defense round. While I don’t wish to be shot with one, it seems perhaps this configuration is not ideal. They were inexpensive and I can always use this supply for training.
I have a few boxes of Black Hills - 100 rounds of 55gr FMJ red box and 100 rounds of 50gr V-max blue box. I also have 40 rounds of Hornady 55gr V-max. I bought the FMJ rounds for function testing and the V-max thinking they too would be a viable defense round.
I may or may not be able to pick up some TAP rounds. I have no idea where I can find M193 rounds, which seem to be better than the M855 for under 200 meters.
If I accept the above data as accurate, and I rely on a 55gr FMJ for defense, whose bullet more closely matches the military M193? If I go with an expanding round, will the AE expand reliably? Will the V-max penetrate enough?
Am I over thinking this, worrying about the “ammo du jour” more than shot placement? I finally learned to stop worrying about caliber and fancy handgun rounds, and just try and shoot straight. I don’t want to start all over again trying to find the best magic rifle bullet.
moonshot
