Ballistics Just Were not Complicated Enough

I’m finally able to carry a full-size automatic while wandering around my property. My Galco Miami Classic II holster arrived.

Until I started looking at it, I didn’t see that it was the same holster I already had for the subcompact Glock. I could just use one holster for both. They have different weights and lengths, however, and adjusting them is difficult, so I decided to have one set up for the Glock 20 and another for the Glock 29.

The Glock 20 is a far superior weapon. It holds almost 50% more ammunition, making it nearly 50% better. The added capacity is more than enough to make it much better than the smaller gun. It has the advantage of being somewhat more comfortable to hold, and it has a longer sight radius, but those things don’t mean nearly as much as 5 extra rounds per magazine.

The big drawback to the shoulder holster is that it has to be adjusted carefully in order to allow the gun to be drawn without a lot of yanking and dancing. It also requires a lot of breaking in before it can be trusted to release a weapon.

It will never compare to the $5 pocket holster I use with the subcompact. That thing lets the gun go instantly and reliably. But the shoulder holster gets things out of the way, and it holds two spare magazines. It also looks nice and could make a useful impression on potential intruders. Open carry is legal on my own land.

Now that the 29 has a Crimson Trace laser on the grip, the Miami Classic will not snap shut on it. The retention strap is obstructed by the laser. I have to decide whether the laser is really a good idea. It works beautifully, but it would require me to cut up my shoulder holster, and it bruises my thumb when I shoot more than a few rounds.

Do I really need it? The gun has night sights, and I’m not the kind of person who needs a lot of help with accuracy. It’s a nice tool, though, and what if I were in a situation where I couldn’t use my usual grip on the gun? That could happen. I might have to use my left hand or something. The laser would make it very easy to aim effectively.

I have some leatherworking skills. I could cut the holster to fit the laser without completely ruining the appearance.

I haven’t decided whether to put a Crimson Trace on the Glock 20.

I’ve been trying to figure my AR15 problem out. I’m just about sure yesterday’s terrible accuracy was not my fault, so the gun or the ammo has to be the problem.

A reader offered a helpful comment about barrel twist. A rifle barrel will turn a projectile 360° in a certain number of inches. Barrels are rated according to that number. For example, a 1:9 barrel has a one-in-nine-inch twist. Different projectiles need different twist rates. A big projectile needs a fast twist to give it a lot of spin, but a small projectile can have problems with too much spin.

What do “big” and “small” mean? I’m not sure. Traditionally, people have said heavy bullets need fast twists and light bullets need slow twists, but I’ve been reading a site that says length is what really matters. Longer bullets need more spin because they’re harder to stabilize. Heavier bullets are usually longer, so people think heavy bullets need more spin. This is the argument.

I don’t know what’s true. As a physicist, I would guess that length is what matters, because a long object will have mass far from its center of rotation, and that mass will have a large effect on rotational stability, so there has to be increased angular momentum (provided by spin) in order to fight any torques that come from that mass.

My barrel has a 1:9 twist, and the sort of bullet it’s made for is not clear. Different “experts” say different things. I saw a source that said it was fine for 55-to-68-grain bullets, but other sites disagree.

I was shooting 55-grain bullets when things went badly. I am guessing, but I don’t think a 1:9 twist is so far off it could account for shooting 5 MOA.

Of course, I am learning these things after spending money too quickly. I ordered a bunch of 40-grain cartridges for the gun days ago. After learning about twist, I was concerned that my non-returnable 40-grain bullets might have been a waste of money.

Not so. I have found out that a gun like mine with a 1:9 twist can shoot the 40-grain bullets I bought with incredible accuracy.

An old guy on Youtube bought the same ammunition and shot it through a gun with a 1:9 twist, and he shot four rounds that made holes that touched each other…at 200 yards. He had some flyers, too, but they were also extremely close to the four adjoining shots. He couldn’t figure out why cheap ammo with the wrong bullet weight worked so well for him.

If the bullets I bought won’t shoot, it won’t be because I have the wrong barrel twist.

I decided to get some 50-grain and 55-grain ammo of the same type, just to see what the story is. I won’t try smaller bullets because I read that really tiny bullets can fly apart and disappear when they spin too fast. They literally disintegrate in front of you while you shoot.

For anything up to the size of a coyote, 40-grain bullets are jim dandy, and light bullets recoil less, so I figured they were a good choice. Now I don’t know. It’s not like the maximum recoil from an AR15 is bothersome, and heavier bullets could be better for some things.

I don’t think any of these bullets are good for self-defense, because they do a subpar job of going deep into large creatures, but the gun isn’t intended for self-defense.

If I can’t get this gun to work, I will talk to the manufacturer. Maybe they’ll take a look at it and find a problem. I’m not too worried about it, because I always thought I was likely to replace the barrel. If it turns out the OEM barrel just isn’t that great, and it’s not bad enough for a warranty replacement, I’ll recrown it myself to see if I can improve the accuracy. After that, if it’s no better, I’ll get an aftermarket barrel and whatever AR15 tools I need to install it.

Sooner or later, we will see this gun shoot 1 MOA at 100 yards. That is for certain, God willing of course.