In this informative video, NRA News contributor Dom Raso, a former Navy SEAL and founder of Dynamis Alliance, reminds us that the AR-15 is the best defense against terror and crime — and he points out that banning AR-15s wouldn’t have prevented most of the recent terror attacks.
Raso also offers his common-sense solution to stemming the tide of terror: Law-abiding citizens prepared to deal with the imminent threats.
Raso highlight quote: “After the attack at Pulse night club in Orlando, Hillary Clinton looked past the obvious enemy — radical Islamic terror — and instead said ‘weapons of war have no place on our streets’ and that we need to ban AR-15s immediately. AR-15s are fine for Hillary and her family. They’ve been protected by armed guards who use them for three decades. But [for] average Americans who watch the news and feel genuine fear for their safety and their families’ safety — Hillary wants to deny them the level of protection she insists upon for herself.”
What did you think of Raso’s “Best Defense Against Terror” video?
This is a specially-adapted excerpt from the forthcoming book, “Handloading For Competition,” by author Glen Zediker, owner of Zediker Publishing. Click here to order from Midsouth.
by Glen Zediker
Maybe the headline above oversells two case preps I routinely perform, but if they aren’t “essential,” let’s at the least say they are “worthwhile.” I don’t like telling folks to endure more tedium than is necessary. Time is not only money: It’s also shooting, relaxation, family, and on down the list of activities that substitute for removing miniscule amounts of brass from cartridge cases.
However, for reasons I’ll hit upon, a couple of actions on the bench make things better, and one makes things safer. The first is a primer-pocket uniforming tool; the other is an inside-flash-hole deburring tool.
The tasks these tools perform only need to be taken once.
When a domestically-produced cartridge case is made, the primer pocket and the flash hole are formed, not cut. The primer pocket is done with a swaging process, and the flash hole is punched. The primer pocket and headstamp are normally produced at the same time with a punch called a “bunter.” I also call it a “blunter” because that’s the result: cross section a case and you’ll see that the bottom of the primer pocket is not square; it looks a little like a cereal bowl. The flash hole is normally punched separately.
A well-designed primer pocket-uniformer’s job, in my view, is mostly to put a 90-degree corner on the pocket bottom, so the bottom is flat. Primers are flat, coincidentally. And this is why it should be done. A uniformer also cuts the pockets to the same depth, which is also within the correct depth range; or, at the least and depending on the combination of the primer pocket and the tool itself, ensures that a minimum depth has been created. That’s between 0.118-0.122 inches for Small Rifle primers.
Now, there are differences among manufacturers in primer-cup heights. They’re small, but tend to be consistent brand-to-brand. A uniformed primer pocket pretty much eliminates the chance of a shallowish primer pocket combining with a tallish primer to create a primer that’s not seated beyond flush with the case bottom.
And all primers should be seated below flush! The actual amount advised or warranted varies with the source, but I give it a minimum of 0.006 inches.
So, after uniforming a primer pocket, the primer should be sitting “flat” on the pocket bottom (more in a bit); ultimately, this means all primers in all cases are seated fully. Measurement of the amount below flush with the case bottom doesn’t really matter; just that the primers are seated fully.
The reason I said “more in a bit” is because primers have an anvil. It’s the three-pronged sort of spring-looking piece on the bottom of a primer. (“Top” or “bottom” is a matter of perspective…) When a primer is seated, the anvil feet compress. Using a hand-held seating tool, you can feel it. They are supposed to compress and be sitting equally on the primer pocket bottom.
There are two reasons this is essential. One is a matter of performance. If the primer is not seated flush against the pocket bottom, then some force from the firing pin or striker is redirected toward fully seating the primer. It’s a softer hit, in effect. This leads to inconsistent ignition, and, to a smaller degree only worried about by the fastidious, differing initial vibration nodes.
The other reason I say this is essential for AR-15 ammo (or for any ammo destined for use in a rifle with a floating firing pin) is assurance against a “slam fire.” Out-of-battery discharge. Ugly. When the bolt carrier sends the cartridge home into the chamber, the inertia can cause the firing pin to continue forward and “tap” off the primer. It’s not supposed to happen, but it dang sure does. The mechanism intended to prevent this is faulty. A primer that’s sitting a little high gets tapped harder, and if it gets tapped hard enough: BLAM. It’s more of a problem with M1As, but I have seen them in ARs, more than once.
Inside-flash-hole deburring is too easy. Of course, you’ll need a tool, and there are several that all work well. When the flash hole is punched, there’s a burr turned up on the inside of the case. These vary in height and scope, but without a doubt interfere with ignition. It’s also possible that a die decapping pin can fold one such that it obscures the hole. Just get it gone. Takes virtually no effort.
It makes a noticeable difference on target, especially in small-capacity, small-diameter cases, like .223 Rem. Reason is clear: the flash from the primer enters consistently and therefore spreads consistently to get the propellant burning. A tall, narrow column of medium-burning propellant is a tougher chore to ignite, or that’s what I think.
The following is a specially-adapted excerpt from the forthcoming book,” Top-Grade Ammo,” by author Glen Zediker, owner of Zediker Publishing. Click here to order.
Last time I gave a caution about respecting one of the differences between semi-auto and bolt-action rifles, and that was with respect to propellant burn rates. The summary reason for that is that different rate propellants will “peak” at different areas as the expanding gases and the bullet travel through the bore. Slower-burning propellants peak farther, and that means more pressure is available at the gas port location in an AR-15, for instance, as the bullet passes it. If the system is oversupplied, then the system is overworked.
Compared to ideal function when gas supply is delivered as engineered, mistimed peak pressures can result in the bolt unlocking too quickly and excessive bolt carrier velocity rearward. The system just gets hit too hard. The extractor tries to yank the case out of the chamber too soon, before the case is released from its grip on the chamber walls (from being expanded through firing). Spent-case condition shows a measurably more abused hull. Probably the worst popular example of these effects is the M1A. I’m doing an entire column or two on reloading for this beast. Essentially, a spent case from an M1A will show dimensions that don’t seem possible. These come from the bolt unlocking too quickly. AR-15s actually handle excessive pressure better than some other designs.
Always keep in mind that this is all happening in about 2 milliseconds. Average time a bullet spends in the barrel, for most modern centerfire rounds, is 0.002 seconds. Timing is everything.
Keeping in mind the behavior of a pressure curve, which is like a wave cresting, factors that influence the amount of gas-port pressure, using the same load, include barrel length, gas-port size, and gas-port location. When the bullet is sealing the bore, the longer the barrel, the more pressure is contained for a longer time. The smaller or larger the gas port size, the slower or faster the gas enters the system. The farther back or forward the port is located, the sooner or later. Bullet weight is a factor also: heavier bullets accelerate more slowly (and also the reason heavy bullets erode the chamber throat more than lighter bullets).
And, the amount of volume inside the bore has a huge influence on all this. That matters when we’re using another caliber than .224 in an AR-15 or .308 in a big-chassis AR (like an SR-25). For instance, in that rifle chambered for .243 Win., but retaining the gas system specifications (gas port size and location) of the .308 Win.–chambered rifle, there’s way more pressure only because there’s less space, less volume, in the bore. The opposite is usually true when we’re running an AR-15 with a larger caliber bullet.
Selecting a propellant with a suitable burning rate, which, again, is something in the vicinity of H4895, is really the only thing we can do on the loading bench to ensure that we’re not contributing to these symptoms. Beyond that, dealing with excessive pressure gets technical.
All my NRA Match Rifles, which usually have 26-inch barrels, get their gas ports moved forward one to two inches. These, of course, are custom-barreled. I also usually install an adjustable gas manifold.
Moving the port forward effectively delays the wave of gas moving through the bore, kind of repositioning its peak with respect to its outlet; there is more space available for expanding gases. It also allows a little slower-burning propellant, which can take more advantage of the longer barrel. It’s common in a similarly constructed AR-10 to get a port moved as much as 5 inches forward to accommodate a .243 Win. or .260 Rem. chambering.
The adjustable manifold allows some tuning. There are essentially two forms these take. One way is to restrict or limit the through-flow; the other just bleeds it off. I like the first kind the best.
Also, I have searched far and wide for a consensus on gas-port sizes, and came up empty.
All this changes with different chamberings and rifle configurations. Carbine-length barrels are particularly sensitive to port pressure because the port is located farther back.
There are a few surefire things that will alert you when your rifle is exhibiting “over-function” symptoms, such as spent-case condition showing excessively blown (extended) case shoulders, extractor marks on the case rim, and a generally explosive sensation in functioning.
In a more extreme circumstance, an over-accelerated carrier can “bounce” back from its rearmost travel so quickly that a round can’t present itself in time to be picked up by the bolt, or the bolt stop can’t engage quickly enough to hold the bolt carrier.
Sometimes what appears to be a “light” load is actually not. I’ve seen excess pressure leave a spent case in the chamber because the extractor lost its grip, and I’ve seen chunks pulled right off case rims. That’s severe. That’s also another cause for the “short-stroke” appearance of over-function: the extractor issue has slowed the carrier.
If you’re having any problems with “over-function,” solutions include retrofitting an adjustable manifold, increasing carrier mass, installing a stouter buffer spring. I do all those things on my rifles. Keep in mind that I am primarily a Service Rifle shooter, and I am trying to push an 80-grain bullet as fast as reasonably possible from a 20-inch barrel that can’t get the modifications mentioned. I know a thing or three about delaying bolt unlocking — I’ll cover more on this topic if you all want to know.