Ammunition And Headspace

A gunsmith must realize that it isn’t always the operating mechanism of the firearm that creates trouble. Abuse is common and so are poor ammunition choices. Lubrication is important and poorly chosen accessories take their toll. Sometimes the design itself is less than ideal. As an example, I recently worked with a lightweight frame .357 Magnum revolver. These handguns have six shot ancestors chambered for the mild .32 Smith and Wesson Long cartridge.

The frame was deepened on the old I frame guns and the Jframe was born as a five shot .38 Special revolver. As many of you know, airweight (aluminum frame) .38 Special revolvers can take a beating in the small parts with +P ammunition. When the same basic gun is chambered for the .357 Magnum anything can happen. This particular revolver would not open when the cylinder latch was pressed. I wriggled the cylinder and it would not release.

I tried the old trick of turning the cylinder in the opposite direction of normal rotation in order to tighten the ejector rod and nothing happened. Finally, I took a thin pick and was able to press the barrel underlug latch forward to release the ejector rod. The ejector rod looked as if it were beat up and the barrel lug latch was actually jammed into the peened section and would not allow the ejector rod to release.

I can only surmise that the heavy recoil of the .357 Magnum cartridge transferred momentum and the result was a wedged part. In the end the revolver was opened and lubricated and the problem did not repeat itself after the offending part was dressed up. The revolver had been brought into the shop in a loaded condition. Having to fire the five loaded rounds out of the cylinder to safely proceed was an eye opener.

The piece kicked like an overweight mule and the blast and noise, even with hearing protection, was tremendous. Before proceeding with ammunition issues we need to discuss the usual run of cartridge malfunctions and how to differentiate between the types. The proper language can be important when dealing with the customer and solving their problems. In a Misfire, the cartridge has been struck in the primer but does not fire. This means the failure is ammunition related.

With a Hangfire, the cartridge is struck by the hammer and there is a perceptible delay in firing. This is also ammunition related. A Squib Load is a cartridge lacking propellent so there’s not enough energy to push the bullet down the barrel. This leads to an article on removing bullets stuck in the barrel. Finally, in a Failure to Fire, if the cartridge shows no signs of being struck by the firing pin, it is the gun’s fault.

There is the possibility of excess headspace, a broken firing pin or a problematic firing pin block. Let’s look at some of the ammunition related problems that have come into my shop during the past few years. Many of you will have similar tales to relate. While this isn’t necessarily nuts and bolts gunsmithing, a gunsmith worth his salt must have a working idea of cartridge malfunctions.

While many shooters say that old time rifles were better made than those produced today, the fact is tolerances of older rifles were often generous. Wood and metal finish was often excellent but modern CNC machinery is more exact. When tolerances were looser there was more case stretching. As a result, the cartridge case stretched and flowed more so than is common with a modern bolt action rifle. I recently examined a Savage 99 rifle with a problem.

The owner brought in several spent cases that exhibited pierced primers, a sure sign of high pressure. These loads worked just fine in his Springfield M1A rifle. The problem was they were 7.62 x 51 NATO rounds, not commercial .308 Winchester, and there is a difference. The loads were too hot for the old action and for a rifle with so much leeway in the headspace. Switching to Black Hills Gold hunting loads, the problem did not occur.

The shooter was using this military ball for practice and honestly didn’t know any better. In this case it was knowledge, not elbow grease, that solved the problem. Another problem occurred with a shooter and a vintage Spanish revolver. He was using an excellent Black Hills .32-20 lead bullet load in the revolver that he first assumed was chambered in .32-20 WCF. There were many made in this caliber but this revolver was unmarked.

The cases expanded fully to the shoulder when fired, making reloading on a handloading press impossible. At first I thought perhaps the revolver cylinder was improperly chambered. Some of these old revolvers are marked .38 Smith and Wesson, .38 S&Wor .38 Special and the chambering is so generous they will accept .357 Magnum cartridges. That is a hand grenade at arm’s length!

The old gent had bent collecting squirrels with this gun and it fired accurately but that old Brothers Hermanos wheel gun wasn’t something I would wish to put more than thirty five dollars in. After conducting more research than the piece was worth, I discovered that the proper caliber in the unmarked pistol was 8mm Lebel (Pistol). While most of these revolvers in 8mm were limited to European sales, with two world wars, a number of revolutions and an open border to the west, any-

thing is possible. Fiocchi still makes was attempting to reload spent cases first class ammunition in this carfrom the same brand and broke his tridge. The shooter shrugged his loading die’s decapper. The primer shoulders upon delivery of the inflash hole was off center! The flash formation and I am pretty certain he hole won’t cause a function problem is still using the low pressure .32-20 but the over-length cartridge case ammunition and getting away with will.

You can waste a lot of time and it, but common sense tells us this is energy attempting to convince a slide not a good situation. On aside note to go into battery when the actual culthe .32 Smith and Wesson Long is prit is poor ammunition. One cannot often recommended for use in a fix bad ammunition and must keep number of European revolvers in proven quality ammunition on hand cartridges from 7.62 Nagant to 8mm for testing. This can become expen- Lebel. Do not substitute!

The longevsive but it simply must be done. ity of both the gun and the shooter Another real problem is the firdemands proper ammunition. ing of .22 Long Rifle cartridges in .22 While we may blame reloads for Magnum chambers. This comes in on many issues, some poorly made faca regular basis.

Some chap has left tory ammunition also gives problems. the Magnum cylinder in the gun, per- Using loads that are too hot in an aluhaps lost the .22 Long Rifle cylinder, minum frame gun is one problem. or isn’t inclined to switch back just Poor accuracy is often the result of a to fire the .22 LR. He may get away bullet cast very hard which doesn’t with a few rounds but the shorter .22 bump up to fill the lands and grooves.

LR is also smaller in diameter and I have also examined domestic comafter a time the end result is often a mercial ammunition with a cartridge split cartridge case. I have seen this case a full 0.002 over the specified with the High Standard Double Nine, length. In another case, a customer Ruger Single Six and other revolvers. The fix isn’t often particularly difficult. I have used simple tools such as a cleaning rod and a good fresh copper brush.

I run the brush in from the front of the cylinder and slowly turn and push at the same time. It only takes a little effort to push the case out of the cylinder enough for the case head to be caught by needle nose pliers. Gently rock the case with the pliers to remove it. If it is stuck a bit worse, pour in Kroil, cap the cylinder with tape and let it sit. I usually let the cylinder set over night. Surplus Ammunition Many shooters shy away from corrosive ammunition, such as available surplus ammunition.

These shooters have heard of such primers turning the bore red, the rusted bores, flash hiders, bolts and generally corroded firearms. And all overnight! Hand loaders have cursed crimped-in military primers, which makes for added difficulty in reloading. This brass must be cleaned much more thoroughly to remove all corrosive residue before reloading. Sure, you have heard all of this, yet there are still plenty of shooters using surplus brass and ammunition without problem. What is corrosive priming?

Corrosive primers contain potassium chloride and sodium chloride. These elements are very stable and make for primers completely stable at both very high and very low temperatures. Soldiers operating in the Aleutians or the sub Saharan desert could be confident these primers will always fire and not demonstrate pressure spikes. While modern technology no longer demands these compounds, in their day they were useful.

Corrosive primers were a slight inconvenience compared to the previous black powder military cartridges. These compositions are actually not corrosive on their own, but rather corrosive in that they attract moisture. If they were corrosive themselves they would rust out of the primer during storage. The bolt, barrel, bore, action, gas cylinder and any muzzle brake or flash suppressor are especially susceptible to corrosion induced by these compositions.

In short, corrosive primers have no negative affect on reliability but rather enhance reliability. Storage conditions are more important than priming. While accuracy and quality control differs, European surplus is often very good. Canadian 9mm Luger ammunition was once highly prized because it would run a German Luger with good function

Learn how to inspect for incipient cracks. Just the same, it isn’t good to use old, corroded ammunition. and accuracy, while domestic loads would not. Greek .30-06 ammunition was highly prized for reliability and accuracy. Yugoslavian 8mm is a good resource to get a good handle on the true accuracy potential of an original Model 98 Mauser. This military ammunition loaded with aspire point bullet is more accurate than commercial loadings and considerably stronger as well.

Thousands of rounds of Com-Bloc 7.62 x 39mm, a smaller quantity of 7.62 x 54mm, and even a small lot of Russian 7.62 x 25mm with a 1943 headstamp have been digested on the local range without a single burp. This stuff was old but hot and accurate, which proves sometimes the Russians got it right. You should regard all military ammunition as corrosive primed and follow the proper cleaning procedure unless you definitely know otherwise. There is no lexicon for foreign loads.

Now we come to the dirty part of the story. Cleaning the firearms is a necessary chore that some feel they may neglect on a whim with modern ammunition. This type of shooter will need to avoid corrosive primed loads. In fact, he may need to avoid shooting much at all because every firearm needs to be cleaned often to prevent eccentric wear from powder, lead and jacket material build up. Cleaning firearms exposed to corrosive priming is similar to black powder.

The firearm must be field stripped, though doesn’t need to be completely disassembled. The old approach of running the parts under hot 45 ACP cartridge on the left almost let go but the head simply swelled. The .45 GAP on the right did burst. Thankfully there was no injury. 38 Super cartridge was fired in a .38 AMU barrel. Bad news all the way around. water certainly is an option, but one that should be used sparingly.

Better to use a powerful ammonia to clean the bolt, bore, trigger mechanism and, in those firearms that use them, the flash hider and gas cylinder. You must be completely thorough in using ammonia. A spray bottle as often used for simple household glass cleaner always works great. It may still be necessary to use hot water after the preliminary cleaning with ammonia. Running the part under the faucet will suffice and it is not necessary to use boiling water. Many firearms area testimony to this program.

Whether or not you are able to save a rifle or pistol exposed to corrosive ammunition depends much upon how long the user has neglected the firearm. Inspecting Ammunition It is essential that we receive a sample of the ammunition used when the problem surfaced, especially if we suspect the problem was ammunition related. The brass should be free of cracks, burrs, dents and such obvious defects. The bullet should be concentric in the cartridge case, not cocked off to one side.

This can be common with .22 caliber cartridges as the bullet is heel based and easily damaged. The overall length should be within specs. The primer should be properly seated and not protrude above the case head. The ammunition should not be corroded. If the problem

isn’t obvious, a firing test is in order. If the ammunition is inconsistent with some rounds demonstrating a louder muzzle report than others, there is a problem with quality control. If the cartridge will not chamber something is wrong. If the primer appears flattened after firing the cartridge is loaded to a pressure that is too high for the firearm. Headspace Headspace is an important consideration and no more true than with the 1911 pistol.

It is much more than simply noting that the case head rim is hard against the breech face. There are actually a number of different categories of headspace. There is static or at rest headspace. This doesn’t change unless there is a great deal of wear somewhere on the pistol. Working headspace is the measurement between the static headspace and the length of the fired cartridge case. A "No Go" gauge from Brownells (brownells.com) is essential for this type of work.

I also use gages from Forster (forsterproducts.com) with excellent results. As you might imagine, headspace varies when you use reloads with differing overall cartridge lengths and also when you use less than premium ammunition. That’s OK if the bullet is cheap and the case is cheap, intended for inexpensive practice. It is not OK when the cartridge case is off specification. The equation is simple. Go is GO plus feeler gauge thickness and that is the headspace when the pistol is at rest.

According to specifications, the minimum headspace for .45 ACP is 0.898 and the maximum 0.920. Most .45 ACP cartridge cases run about 0.898 to 0.900 inches long. At what point headspace is dangerous is worthy of some debate. If the chamber is cut too deep the gun may be quite safe. If the locking lugs do not set correctly there is more likelihood the headspace will be dangerous.

As long as the cartridge is seated it is OK, but when the breech is open during firing, well, the cartridge case head has lost chamber support. That is a bad thing. When the 1911 fires the slide and barrel recoil together. At the moment of firing the lug engagement holds the barrel. The barrel is pressed forward by bullet thrust and the expanding gas of the powder burn pushes the slide to the rear.

That is where the pressure comes from, and even at a modest 18,000 PSI or so there is plenty of gas pressure for a ruptured case to injure the shooter. The worst scenario allows the case to travel with the breechface too soon from the chamber and the cartridge case head ruptures. Be careful when measuring headspace. The gauge starts between the breechface and measure the rim from beneath with the slide moved from battery. Press the gauge into the slide and it should be removed with just slight resistance.

It isn’t safe to use alive round and dummy cartridges are not exact enough. Use anew brass case from Starline or a once fired and resized cartridge case. Just a sliver is all that should be allowed. The wrong caliber cartridge may have awesome consequences, including blowing up a collectable firearm. A few years ago I examined a vintage Colt that was clearly marked .38 Super.

At the first shot with .38 Super ammunition the case burst and ruined aid in removing a stuck case. known-quality ammunition on hand the barrel. Upon examination the barrel had been sleeved for the .38 AMU, a rimless .38 Special widely used in competition in military circles a few decades ago. Could the owner have known? No, not unless he was more knowledgeable than ninety per cent of the shooters in my circles. The personnel at the gun shop didn’t know and neither did I.

The handgun could not be returned to original condition, at least not easily, but the addition of a .38 Super barrel from Bar-Sto (barsto.com) and premium recoil springs from Wolff Gunsprings (gunsprings. com) solved the problem. The fellow ended up with a nice Colt but spent much more than he had first thought. At least the wreck wasn’t a total loss! As a sideline, not long after I also fitted a Bar-Sto 9mm barrel and obtained Metalform (metalform.com) 9mm magazines to make this Colt even more versatile.

I am glad no injury occurred and, in the end, this was more productive work for the gunsmith. When you are working with firearms, the mechanics are very important but the accessories such as the grips and the ammunition are also important. You must look at the whole picture to reach a valid conclusion. A shelf full of reference books not only on gunsmithing but on cartridges as well is important. AG