Bio

Great day for off-angle shooting (and math)!

How far away is that car? Its license place covers two milliradian in the reticle, and plates are always 12 inches across. (T-in * 27.76/T-mil). So it’s 166 yards away.

So, set the scope for 166 yards? Not yet. You’re 90 feet above the target, so the bullet only is affected by gravity for ((A*A)+(B*B) = Hyp). So, 163 yards.

Wind is 10 knots gusting to 15 from 45 degrees (half value) but wind correction, well, it’s still 166 yards of wind. So hold left 0.5 mils.

Now…breath. Relax. Just gentle pressure on the trigger.

Send it.

Pick your “truck gun”:

4” MPX (9mm) vs 10.5” AR (5.56mm). What’s your pick and why?

Weight - Same (8 lb 2 oz).

Overall length - Same (when MPX is suppressed).

Accuracy – 5.56mm (1” vs 3” at 50 yards).

Range – 5.56mm = 300-400 yards. 9mm = 100.

Capacity – Same (30 rounds).

Lethality – With typical ammunition (M855, 55 FMJ), 5.56mm from a short barrel will be less effective than 9mm JHP. With a premium bonded round, the 5.56mm will outclass 9mm JHP.

Report –The 5.56mm will cause immediate and permanent hearing damage. The 9mm is hearing safe.

P.S. Is a rifle caliber always better than a pistol caliber? Check out the ballistics of a 5.56mm below 9” to a 9mm of the same length, and you might be surprised.

I know a cartridge can’t make your barrel longer, but can it make it act like a longer barrel?

As it turns out, yes. We used a 55-grain open tip and a bonded soft point. For each option, we selected both 5.56 (hot) and .223 (normal) pressures as loaded from the factory.

The results showed that a .223 round, on average, is about 230 fps slower than one loaded to 5.56-mm pressure. So, hotter ammo is faster. That easy. But when dropping from a 14.5” barrel to an 11.5” barrel, you almost always lose 200 fps.

Here’s where the numbers are most interesting. Look at the blue shaded boxes in the chart. The 14.5” with .223 ammo and the 11.5” with 5.56-mm loads both end up at around 2,700 fps. It’s the same bullet, and it’s going the same speed. So, it’s the same ballistics.

Look at the orange box and you’ll see the same thing. The 14.5” with the .223 round produces slightly less velocity with the same bullet as the 11.5” barrel with the higher-pressure 5.56 loaded rounds. Again, you get the velocity back from the shorter barrel by loading 5.56 pressure rounds.

You might ask: who cares about a measly 200 feet per second? Well, remember that in real-world testing, the mighty 300 Win Mag launches a 168-grain slug at about 2,990. That’s only 230 fps faster than the lowly .308 when both have 24” tubes. So, yeah. 200 extra feet per second is a big deal.

You can’t load a round that makes your barrel longer, but you sure can make it act like one.

The Shield Arms S-15 magazine is arguably the best innovation in Glock aftermarket products for this decade.

As such, it has become very popular for G43X owners, but with mixed reviews on reliability. Shield offers a 10-coil mag to improve reliability, but some users still encounter stoppages. After 3,550 rounds of testing on three 43X's we determined that the 12-coil spring provides the best reliability with a reduction to 14-round capacity. (They are all Glock springs, so just get one from your favorite gun store.)

We all want G19 capacity in a G43X frame, but you can't put a 350 in a Miata without a few tweaks.

Be safe, and send it!

I got to spend the day with my old buddy and US Border Patrol Firearms Program Manager. He brought me one of their G47s. You can’t buy one of these in stores! It’s like a G17 that can slide swap into a G19 or a G45. Cool stuff!

#honorfirst

My most recent tinkering: I rebuilt an old AR that has been run hard. This blaster has had only 3 stoppages in 7,100 documented rounds! It has worn a suppressor for nearly all of it. There were a grand total EIGHT times it was cleaned in 11 years. In the photo, you can see the gas block was essentially 99% closed and seized in place. It’s evidence of how little gas a suppressed AR needs to run reliably, even when it’s filthy.

Glass Mountain.

In May 2010, a man detonated a bomb outside a place of worship in Jacksonville, FL. After learning a federal agency suspected him as the bomber, he fled the state. A year later, in 2011, the subject was located in Glass Mountain state park in Oklahoma. A federal SWAT team was activated and a two-man sniper team was sent out that evening to locate the subject under cover of darkness. After a long patrol, and using only night vision to search and navigate, the snipers located the subject. The snipers quietly positioned themselves on top of a nearby mesa and set up a surveillance position until the sun came up and the assault team moved in.

After a standoff that went into the early afternoon, the subject emerged from his tent firing an AK-47 at the assault team operators. At this point the snipers had been awake for over 31 hours and had been lying motionless and out of water for several hours. Upon seeing the subject firing his rifle, the sniper immediately engaged the subject with one round from a .308 sniper rifle at a range of 210 yards and ended the threat.

Considerations: Despite the average sniper engagement falling under 100 yards, be prepared for longer ranges. Know your holdover, wind deflection, and down-angle calculations. Brace yourself for lack of sleep and dehydration. Sweat in peacetime so you don’t bleed in wartime.

Whoever said trigonometry isn't fun, didn't understand the application to long-range ballistics. SOH-CAH-TOA is the mantra of the modern marksman!

We got to provide some precision live-fire for Oklahoma State University while testing a stadium active-shooter detection system. Many thanks to the engineering students who designed the bullet trap!