05July06

Some good advice on frangible 223, from a friend who uses a lot of it:

"Stay away from iron-based frangible, such as Remington's 'Disintegrator.' Iron residue stays hot for a LONG time after impact, and has started several range fires. Copper/polyester projectiles are light and require a hot loading in order to reliably cycle the action on most autoloading rifles. The invariable result is a fast bullet that surely disintegrates upon impact, b ut is still going fast enough to generate momentary impact temperatures high enough to melt steel and thus leave pock marks.

The best frangible 223 bullets are copper/tin. Density close to lead, and the bullets are hard enough to successfully crimp to the case. We recommen d nothing faster than 2,800 f/s. Stay below that, you should see no damage o n high-quality steel targets."

Comment: Even the best frangible 223 is still going to be far less satisfactory than conventional bullets, even in training. I don't like it, but, when compelled to use it, I'll opt for the best performer available.

/John

05July06

On "Frankenguns," from a friend and well-known riflesmith:

"Many don't know that the M4 requires a different front sight housin g than does the old style. The correct front sight housing will have an "F" stamp ed in it. Correct M4 front sight housing will be a nominal 1.970" from the to p of the barrel to the flat between the sight ears.

An M4, put together with an 'old' barrel (and sight housing) will invariably shoot high, way beyond the ability of sights to correct. Many p rint four inches or more above the point of aim at twenty-five meters!

Those with 'Frankenguns' (cobbled together built from whatev er parts can be found, scrounged or bought cheap at a gun show) should be on the lookout for this. Most M4s that consistently print high have the wrong front-sight housing. Plug that same barrel into a standard upper, and it will probably zero just fine."

Comment: We see "Frankenguns" in courses. Few work well! A s they come form the factory, ARs are far from perfect, but at least most manufacturers have some idea of what it takes to produce a serous, utility rifle. Many scanty-documented updates have come and gone in the forty years the AR-15 h as been around, as noted above. Best advice is acquire a factory rifle and then tr ain yourself around it. Learn to use it as it is, keeping modifications to a minimum.

/John

05July06 Cor-Bon DPX and car doors: At a pistol course last weekend, I had the opportunity to shoot up several expendable vehicles we had on the range, expressly for that purpose. We used the vehicles (a late-model Jeep and a late-model Honda) as props during several tactical exercises, and then we shot them with various rounds in order to give students first-hand knowledge and experience with the issue of vehicle penetration. As a general statement, high-performance pistol bullets, at typical pistol velocities, are disappointing on car doors, failing to penetrate most of the time. In fact, even most 223 rifle bullets don't do much better in this regard than do pistol bullets. Car glass, particularly when struck at shallow angles, is also rarely penetrated, and, when it is, the path of the bullet is radically altered, sometimes by almost ninety degrees! That foregoing generalization was largely confirmed by our experience last weekend. Car doors are, or course, not homogeneous, and bullets do occasionally sail through, but, while most penetrate the outer skin, the vast majority fail to punch through the inner layer and carry on into the car itself. It was my intention to compare 45ACP DPX (160gr), which I carry in my Detonics 9-11-01 (1911) with other, quality, high-performance pistol ammunition. We shot car doors from all sides, but the most relevant test, in my opinion, was when we shot into the door at a thirty-degree angle, as would be the case when I would shoot at someone who is using the partially-open door for cover. Results were dramatic! With this angled-impact test, most high-performance hollowpoint pistol bullets penetrated through-and-through less than ten-percent of the time. Even when they did, upon exiting they were badly mangled and had lost much of their weight. What exited was actually just the biggest piece! DPX, on the other hand, penetrated over eighty percent of the time, and the bullet stayed in one piece in nearly every case. This experience confirmed my decision to carry DPX in all pistol calibers I normally carry, including 380Auto, 9mm, 40S&W, 357SIG, 45GAP, and 45ACP. (1) It expands reliably in soft tissue, even after penetrating heavy clothing. (2) It is not deflected by car glass, even during angular penetration. (3) And, it punches through car doors vastly more reliably than does nearly any other pistol bullet. Highly recommended! /John