Wednesday, April 10, 2019

.22LR maximum range considerations




I was touring a site that will be featured in some future installments in the Skinny Cows series. I had a subject matter expert with me and he challenged me on the utility of the lowly .22LR.

This post captures some of the discussion.

Trajectory
"Point Blank Range" is the maximum distance the shooter can hold in the center of the intended target and still hit it.

Two things come into play, how 'flat' the arc of the trajectory is and the vertical height of the target.

When talking about the .22LR, everybody assumes you are using it for small game. That is, you plan to shoot squirrels and rabbits in the head.

Assuming 1200fps, 40 grain bullet and a ballistic coefficient of 0.125, then the trajectory might look like this
A typical .22LR trajectory with a 65 yard "second zero". Maximum mid-flight rise of 0.7 inches above the line-of-sight and max "point blank range" of 75 yards.


75 yards is not a very useful range. Assuming the zombie formation is heading south down the road in the center of the image, the shooter at the woods doesn't have a chance.
What if you are shooting zombies and can only take brain shots. That presumes a four inch vertical target.

A second zero of 85 yards results in a maximum mid-flight rise of 2 inches (half the four inch target). Maximum range is 100 yards when the bullet is now 2" below the line-of-sight.
For those who are very new to this game, one does nothing to the rifle, one adjusts the scope to change the line-of-sight.

What if your species of zombie has a vertical target height of 24 inches, which coincidentally is exactly the distance between the top of the pubic tubercle and the bottom of the clavical of a 50th percentile, American male.

A second zero of 165 yards gives an effective range of 200 yards for a 24 inch tall target.
A 165 yard zero, in this case, allows the shooter at the woods line to effectively a line of zombies on the road. The bullet will be 5" above the line of sight at 150 yards (blue arc) and 4" below at 175 yards (red arc) allowing the shooter(s) to effectively cover a significant length of the road.
The risk is that the zombies might charge the shooters. That is a problem if the zombies are smart enough to advance in rushes and drop prone when not advancing.

If they are naive enough to remain standing during the entire rush, the shooter can engage them the entire distance as the max rise is ten inches.
Another consideration is the septic nature of .22LR projectiles.

Look at that hollowpoint. That shouts of belly-button fuzz. These bullets typically get carried around in pockets. Many of them are lubricated with wax. The wax or the hollowpoint get contaminated by whatever type of dust is in the pocket.

This particular round is copper plated. Click on the picture to embiggen and look at how rough and flaky the surface is. Look at how jagged and rough the edge of the cavity in the nose is. You can even see a small hair captured on the left side of the bullet. That was not planned.

That may not be a big deal now, but think of a world where contact with dirt and pig feces is common. A world where soap is expensive, hot water is rare and where penicillin is non-existent.

That world is the one where getting hit by even a lowly .22LR is a death sentence. Death may not come quickly. Many historical accounts tell  us that many duelers lived for three days-to-three weeks after being shot. But long term survival of those who experience a deep wound will be rare.


5 comments:

  1. Some time back there was a blog post(lawless?) about some fellows shooting 400 yards at 6" steel; with .22 SUB-SONIC.
    Can't find it.

    ReplyDelete
    Replies
    1. The sensitivity when you get way out on the rainbow is that slight error in estimating the range result in shots that are high or low.

      It is less of an issue when you are shooting steel at precisely measured ranges or you can dial your scope into the correct elevation.

      Field shooting is a different kettle of fish.

      Consider the .22LR that is dialed in for squirrel shooting. You might estimate the range as 200 yards when in fact it is 150. If you held 42 inches over (three and a half feet) your shot will hit 24 inches high.

      IMHO, the key point is that it is essential to have first hand knowledge of your potential battle field AND to integrate realistic expectations of your target's vertical dimension into your plans.

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  2. When I first came to Alaska in the early 1970's I worked with an old timer who came up in 1929. He told about shooting bedded moose in the lungs with a .22 and then sitting down until they had time to bleed out. If the got up and ran you lost the meat. That said if I were sniping raiders with a .22 I would get in a couple shots and hightail it alla Lexington and Concord 1775. Possibly set a secondary ambush because you sure don't have the stopping power for close quarters.

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  3. Further thoughts on the effectiveness of the .22. Ronald Reagan would have bled out if he hadn't been real close to one of the best trauma hospitals in the country. Killed Bobbie Kennedy outright but that was a close range head shot.

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    Replies
    1. Roughing out some expectations:
      Most people will follow the script they saw in the movie if hit by any bullet. The will flop around, run thirty yards fall down, wail and die.

      It is a mental thing.

      A deer sized animal, physically, will run fifty-to-a-hundred yards, bed down, lick its wound and die.

      Most mission oriented humans could absorb two upper-center-of-mass hits from a .22LR (heart/lung shots). In most cases they would get shaky at forty seconds, lose functional consciousness in four minutes and be clinically dead in ten.

      A lot can happen in forty seconds. There will be outliers who go on to live their three score and ten while other outliers will be dead on their feet.

      Most motivated humans are going to look at their squad mates and emulate them in the last forty seconds of lucid thought. If the squad is hunkered down and shooting, most likely the well hit target will do the same. If the squad is charging the bunker, the well hit target will follow.

      The instinct to run with the herd is likely to dominate until the very last conscious breath.

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