March 29th, 2019

Inspect Your Fired Brass to Avoid Catastrophic Case Failures

Glen Zediker reloaders corner midsouth book AR-16 reloading semi-auto brass safety primer resizing
Close-up view of a sectioned case. This one here was “fixin’ to pop”, says Glen Zediker.

Here are highlights from an article Glen Zediker wrote for the Midsouth Blog. In this article Glen focuses on cartridge brass. Glen discusses the most common failures that appear with brass that has been shot multiple times, or which has been fired at excessive pressures. Glen explains some simple ways to check your cartridge brass to detect “early warning signs” of case failure, particularly case head separation, which can be dangerous.

Glen is the author of many excellent books on reloading. This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com.

Handloading for Competition
by Glen Zediker

The Competitive AR-15
by Glen Zediker

Top-Grade Ammo
by Glen Zediker

How Cases Degrade with Multiple Firings By Glen Zediker
This article explains when, and then how, to check after the progress of changes commencing with the firing on a new case. It’s the “progress of degeneration,” in a way of looking at it because the concern is getting a handle on when enough change in the brass has come about to require attention. Or abandonment. As said then, for me that’s 4 firings. That, as said last time, is when I might see changes that need attention. Also as said, that figure didn’t come out of a hat, but from my own notes in running my competition NRA High Power Rifle loads. [Editor’s Note: With Lapua brass, using moderate loads, in bolt-action rifles, we typically get about 10 good (match-worthy) firings. But if you anneal your Lapua brass, and run modest pressures, Lapua brass can perform well for 20 or more load cycles.]

The areas most affected are the case neck and case head area. Case neck walls get thicker [but] the case head area body walls get thinner. Primer pockets get shallower and larger diameter.

Glen Zediker reloaders corner midsouth book AR-16 reloading semi-auto brass safety primer resizing

This case shows a cracked neck AND a crack (separation) above the case head. Zediker says it is “rare to see one case with both of the most common failures. [This case] was attacked by an M14.”

Case Head — Causes of Separation and Cracking
When a case is under pressure during firing, the brass, like water, flows where it can, where it’s more free to move. Of course, the chamber steel limits the amount it can expand. The case shoulder blows fully forward and the case base is slammed back against the bolt face. There is, therefore and in effect, a tug on both ends — it gets stretched. The shoulder area is relatively free to expand to conform to the chamber, but the other end, the case head area, is not. Since that’s the area of the case with the thickest walls, it doesn’t expand “out” much at all. What it does is stretch. The “case head area,” as I refer to it here, is the portion of the case above the web, which is just above the taper that leads in to the extractor groove. The “area” extends approximately an eighth-inch up the case body.

Glen Zediker reloaders corner midsouth book AR-16 reloading semi-auto brass safety primer resizing

Here’s a “pressure ring.” You’ll see this after firing, if you see it. And, if you see it, that case is done. The bright ring indicates excessive stretching, which indicates excessive thinning. If you see a ring circling the case, noticeable because it’s lighter color than the case body, and it’s in this area, I’d say that case is done. And that’s right where a “head separation” occurs. It can crack and also blow slap in two, and that’s the “separation” part of case head separation.

Case-head case cartridge pressure ring separation head failure GS Arizona
Photo courtesy GS Arizona.

This is a spot to keep close watch on as cases age. It is also the area that is more “protected” by sizing with less case shoulder set-back. That is, pretty much, where the freedom for the stretching movement in this area comes from (the case shoulder creates a gap). If you’re seeing a sign that a head separation [might happen with relatively few firings], chances are the shoulder set-back is excessive, and also… the load pressure level.

Bent Paper Clip Case-Wall Gauge
Case-Head Separation paper clip Glen Zediker GS Arizona

Editor: You can use a bent paper clip to detect potential case wall problems. Slide the paper clip inside your case to check for thin spots. GS Arizona explains: “This simple little tool (bent paper clip) will let you check the inside of cases before you reload them. The thin spot will be immediately apparent as you run the clip up the inside of the case. If you’re seeing a shiny line on the outside and the clip is really hitting a thin spot inside, it’s time to retire the case.” Photo by GS Arizona.

Monitor Primer Pocket Dimensional Changes
Another case-head-area and pressure-related check is the primer pocket. As said, the primer pocket will get larger in diameter and shallower in depth each firing. As with many such things, the questions are “when” and “how much,” and the main thing, “how much?”

If the pocket gets excessively shallow, and that’s judged by a primer that seats fully but isn’t at least a tick below flush with the case base, there could be function issues. There’s a risk of a “slam-fire” with a semi-auto that uses a floating firing pin, and, if there is actual protrusion, that has the same effect as insufficient headspace. A primer pocket uniformer can reset the depth of a shallowed primer pocket to what it should be, but the real test for me is how easily the next primer seats into it. If it’s significantly less resistance, I’ll say that case is done. Shallower can be refurbished. That’s a primary function of a primer pocket uniformer. Larger diameter, though, can’t be fixed. I’ve mentioned in another article or two that, any more at least, my main gauge of load pressure has become how much primer pocket expansion there’s been.

AR15 Glen Zediker Practical AR-15 book newGlen’s books, Handloading For Competition and Top-Grade Ammo, are available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

Glen’s newest book, America’s Gun: The Practical AR15. Check it out HERE!

Permalink - Articles, Bullets, Brass, Ammo, Reloading, Tech Tip No Comments »
March 29th, 2019

People Pleasing Pistols — Best-Selling Handguns of 2019

Best selling gun genius firearms pistol Sig P320 gunbroker

Looking to acquire a handgun for personal protection of home and family? There are countless options on the market. Your buying decision may be simplified by seeing what other consumers have chosen, as revealed by nationwide sales trends. You can now check firearms sales figures using “Gun Genius”, a new data-crunching service of Gunbroker.com. On GunGenius.com you can select any type of firearm (handgun, rifle, shotgun)* and see the top sellers for that category.

Here are the five (5) top-selling NEW semi-auto handguns for Q1 2019:

Best selling gun genius firearms pistol Sig P320 gunbroker

And here are the five (5) top-selling USED semi-auto handguns for Q1 2019:

Best selling gun genius firearms pistol Sig P320 gunbroker

*Chose semi-auto pistols, revolvers, semi-auto rifles, bolt-action rifles, lever-action rifles, single-shot rifles, semi-auto shotguns, pump shotguns, and more. You can also filter for sales trends (upwards and downwards). Drill down to see detailed product specifications and current prices.

Permalink Handguns, Hot Deals, News No Comments »
March 29th, 2019

Breath Better… To See Better (and Shoot Higher Scores)

Vision Eye Target Scope Relaxation Oxygen Target

Do you find that the crosshairs in your scope get blurry after a while, or that you experience eye strain during a match? This is normal, particularly as you get older. Focusing intensely on your target (through the scope or over iron sights) for an extended period of time can cause eye strain. Thankfully, there are things you can do to reduce eye fatigue. For one — breathe deeper to take in more oxygen. Secondly, give your eyes a break between shots, looking away from the scope or sights.

In our Forum there is an interesting thread about vision and eye fatigue. One Forum member observed: “I have noticed recently that if I linger on the target for too long the crosshairs begin to blur and the whole image gradually darkens as if a cloud passed over the sun. I do wear contacts and wonder if that’s the problem. Anyone else experienced this? — Tommy”

Forum members advised Tommy to relax and breath deep. Increase oxygen intake and also move the eyes off the target for a bit. Closing the eyes briefly between shots can also relieve eye strain. Tommy found this improved the situation.

Keith G. noted: “Make sure you are still breathing… [your condition] sounds similar to the symptoms of holding one’s breath.”

Phil H. explained: “Tom — Our eyes are tremendous oxygen hogs. What you are witnessing is caused by lack of oxygen. When this happens, get off the sights, stare at the grass (most people’s eyes find the color green relaxing), breath, then get back on the rifle. Working on your cardio can help immensely. Worked for me when I shot Palma. Those aperture sights were a bear! The better my cardio got the better and longer I could see. Same thing with scopes. Try it!”

Watercam concurred: “+1 on breathing. Take a long slow deep breath, exhale and break shot. Also make sure you take a moment to look at the horizon without looking through rifle or spotting scope once in a while to fight fatigue. Same thing happens when using iron sights.”

Arizona shooter Scott Harris offered this advice: “To some extent, [blurring vision] happens to anyone staring at something for a long time. I try to keep vision crisp by getting the shot off in a timely fashion or close the eyes briefly to refresh them. Also keep moisturized and protect against wind with wrap-around glasses”.

Breathing Better and Relaxing the Eyes Really Worked…
Tommy, the shooter with the eye problem, said his vision improved after he worked on his breathing and gave his eyes a rest between shots: “Thanks guys. These techniques shrunk my group just a bit and every little bit helps.”

Read more tips on reducing eye fatigue in our Forum Thread: That Vision Thing.

To avoid eye fatigue, take your eyes away from the scope between shots, and look at something nearby (or even close your eyes briefly). Also work on your breathing and don’t hold your breath too long — that robs your system of oxygen.

eye vision Vince Bottomley

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