Archive for the 'AR-15s' Category

Ammoland

I had always wondered how easy or difficult this would be.  It looks like it just requires some basic tools and a little patience.

I especially like that they got a gunsmith to explain it, and he provided pictures.

Whether a product is worth the price, recall from Mike Vanderboegh, depends upon what it can demand on the market.  DD can demand this kind of money, and thus, they are worth the money – to a least enough buyers to keep them in business, and expand their business to become one of the largest AR-15 manufacturers in the game.

Military.com.

Most importantly, the new M16A1 came with a cleaning kit, lubricant and an entertaining field manual, drawn by Will Eisner, the former Army comic artist who designed vehicle manuals in World War II. It was called “The M-16A1 Rifle: Operation and Preventative Maintenance,” otherwise known as “Department of the Army Pamphlet 750-30.”

[ … ]

The comic was easy to read, entertaining and — above all — a familiar look to American GIs in Vietnam. Many of them would have been familiar with “The Spirit,” a comic about a Batman-like masked vigilante he created before the United States entered World War II.

By 1968, more American troops in Vietnam began to accept the use of the rifle as malfunction incidents decreased dramatically. The powder used in the 5.56 cartridge was upgraded to reduce the fouling of various parts of the weapon. By 1969, the M16A1 was fully accepted as the standard infantry weapon for the U.S. military.

I’ll bet if you had an original of this it would be worth a lot of money.

News and opinions.

Combined with the current military M855, or even better the Designated Marksman “Match” ammunition, the M-16 platform can take us well into the new century. The military has decided just that by declaring that there is no reason to adopt any of the new weapon systems anytime soon. There are special units deploying ACRs (advanced combat rifles) but their chance at widespread use anytime soon appears to be zero.

Personally, I have tried most of this new generation of rifles and they are just bigger, bulkier and more complicated. Some are just downright ugly! I would take an M-16 style rifle over any of them.

Surprising to many, the “AR” is about 65 years old, older than almost everyone reading this, and it is still going strong. It is our longest-serving service rifle of all time, by a large margin, and every year it just increases that lead.

Almost every other country in the entire world has adopted the cartridge of the M-16, if not the entire M-16 itself, and those that haven’t basically copied it.

For a rifle that so many people supposedly hate, it has completely dominated the world. I am happy to be a fan and user of the “Black Rifle.”

I’m even prouder to be a citizen of the country that designed, adopted and fielded it with such success.

While I’m not a fan of the green tip ammunition, this is a fairly well-informed article and has good history as well.

Guns Magazine.

To understand how we got here we need to look at its military origins. Some years ago I had the pleasure of meeting Eugene Stoner at the SHOT Show. We were able to sit down and chat for an hour or so, which I considered a privilege then and still do.

Back in the 1950s, he said, the U.S. military had just adopted the M14 rifle using the 7.62mm cartridge, ballistically similar to the .30-06. What might be called the “Old Guard” supported the concept of powerful battle rifles and carefully aimed fire at individual targets.

Other military theorists noted enemy soldiers for the most part don’t stand around in the open waiting to get shot. They hide behind things and shoot from cover. Combat in WWII and in Korea had shown the value of suppressive fire, “shoot and move,” and the integration of infantry, artillery and air power.

The rifle they wanted would be lightweight, with moderate recoil, selective semi- or full-automatic fire, compact and fast-handling for house-to-house fighting and adequately powerful, using non-expanding bullets. Hmmm, you don’t want much, do you? Stone said the only way he knew of to make a small non-expanding bullet behave like a bigger bullet is if it tumbles on impact. Original rifles had a 1:14 twist so bullets were just barely stable in flight, but would destabilize and tumble when they hit something.

Almost as soon as it was adopted the twist was changed to 1:12 to improve stability, which some argued also decreased effectiveness. In the ’70s and ’80s military users began shifting to heavier bullets for improved downrange ballistics, requiring faster barrel twists. It took a while, but faster twists eventually appeared on sporting rifles.

Faster twists and sleeker bullets, notably from Berger and Hornady, greatly enhance the versatility of the .223. Compare a 55-grain FMJ bullet (G1 B.C. 0.243) at 3,200 fps to a Berger VLD 80-grain bullet (G1 B.C. 0.455) at 2,750 fps. With both sighted at 200 yards, bullet drop at 600 yards is 91.5″ for the 55 grain versus 82.3″ for the 80 grain. Now check the 10 mph wind drift figures: 55 grain, 60.8″; 80 grain, 32.5″. That nearly 50 percentage advantage in wind drift is huge. Moreover the 80-grain bullet starting out 450 fps slower reaches the 600-yard line going over 400 fps faster (1,271 55 grain, 1,680 80 grain).

So what is a fast-twist .223 good for? Training with moderate recoil and noise. Teaching new shooters the fundamentals of center fire rifles and longer range shooting. Moderate cost due to smaller bullets and powder charges. Excellent hunting performance for most varmint shooting and for deer, the most popular big-game target. Untold millions and billions of .223 and 5.56 rounds have been loaded over the past 60+ years. Even in times of chronic shortages there’s a good chance of finding quality brass.

In my experience 1:9 will stabilize 70- and some 75-grain bullets, 1:8 will stabilize up to 80-grain bullets. Here’s some examples of twist rates in various rifles. The Savage Elite Precision is 1:7. Browning X-bolt, Ruger American, Sako 85 and Tikka T3X are all 1:8. Ruger’s Hawkeye, Howa, most Savage models, Kimber, Steyr and Weatherby Vanguard are all 1:9. Decide what your priorities are then buy accordingly.

I have heard that from multiple experts (i.e., that 1:9 twist barrels will stabilize 62 and 69 grain bullets, or even slight heavier like the Sierra Match King bullets).

I too and very fond of the round.

And I love hearing stories about Eugene Stoner.  I think we ought to build statues of him and John Moses Browning as the premier weapons designers in American history.

As I think about it, the only thing I ever thought it might do to consistently shoot 5.56mm in a rifle chambered for .223 is throat erosion.  I think they confirm that.

Reuters.

TOKYO, Aug 17 (Reuters) – The Russian Kalashnikov AK-47 and its derivatives have long been the assault rifle of choice for militant groups because of their rugged design, but some Taliban fighters are trading them in for captured U.S. guns as Afghanistan’s government collapses.

Video and pictures published by the Taliban on Twitter and elsewhere show fighters carrying M4 carbines and M16 rifles discarded by Afghan army units. Other images show Taliban forces capturing abandoned government vehicles.

Because it’s a better rifle.

Shooting Illustrated.

In addition to recording a series of internal and external measurements, I visually inspect every barrel that comes into my hands from end to end, inside and out. Special attention is paid to the crown, feedramps, gas port, muzzle and bore. The crown is checked under high magnification for burrs, gouges or other imperfections that can cause projectiles to leave the barrel inconsistently, diminishing potential accuracy in the process. A magnifying glass or jeweler’s loupe and a good light will go far to help you see how this critical transition from bore to muzzle face has been cut. Most barrels have some form of recessed crown that are cut at varying angles, depending on the maker and barrel type. My experience is that the degree of crown is far less important than how cleanly cut and uniform it is.

Damage to a new barrel’s crown can be caused at any point along the way between production and installation and this is certainly not unique to the AR. Crown damage on any rifled barrel should be carefully evaluated to ensure it is not going to cause problems during firing. If the barrel arrived with an already-damaged crown, I would contact its source in hopes that they will exchange it for a new one before troubling yourself to fix it.

Flawed or damaged crowns can be cleaned up through the use of either hand crowning tools or a machine lathe. If you are only dealing with a single barrel, the most cost-effective route to repair is through a gunsmith. However, if you lack a lathe but are regularly dealing with banged up crowns, investing in a good hand crowning tool will pay for itself in the long run.

After checking the crown and if the muzzle is threaded, I always “chase” the threads with a properly-sized die to ensure they are fully cut and cleaned up. Just behind those threads, the shoulder is the next area that I check. If you plan to use a sound suppressor, this shoulder should be square with the bore and threads to ensure proper suppressor alignment.

This is true for both direct-thread suppressors and those that use QD mount-style muzzle brakes and flash hiders. If your muzzle device seats on the face of the muzzle instead of the shoulder, the muzzle face will need to be checked instead. I seldom see damage in these areas, but occasionally a barrel comes from the factory with a flaw that would prevent a muzzle device from seating squarely. I use a lathe to slowly spin barrels while I check runout [with gauges] on shoulders or muzzle faces, then remedy any flaws at that time. Again, a gunsmith or machinist can perform this check in just a few minutes and even if it needs to be re-faced, it is a simple operation.

Whether or not you have this check performed, I strongly recommend that at a minimum, you use an alignment rod to verify that your suppressor and bore line up correctly before live firing the system.

Sliding back along the barrel a few inches, we should find a gas port that is drilled at top-dead-center of the barrel when mounted in a receiver. Most manufacturers drill their ports once the barrel extension has been installed so that the index pin, which nests in the upper receiver’s index notch, actually performs its namesake function. Nonetheless, once in every hundred or so barrels, I find one that has the gas port and index pin out of alignment. If the misalignment is more than a couple degrees, there is a pretty fair chance that a properly timed gas block will result in reduced/restricted gas flow, impeding operation and increasing wear of the gas block itself. Unfortunately, there aren’t any great options to repair this problem. If you lack the correct tooling to install and remove a barrel extension, this manufacturing error is best left to a gunsmith or (preferably) the manufacturer to remedy.

A simpler and far more common problem is having an undersized gas port. A decade or so ago, barrel makers tended to oversize gas ports, especially on service-grade barrels. The prevailing wisdom being that it was better to have too much gas and keep the gun running rough and dirty than too little gas preventing it from running at all. It was left up to gas block makers and gun builders to figure out how to modulate the excess gas, especially when using a sound suppressor.

The situation is nearly the opposite today, as both match and rack-grade barrels are frequently sold with ports that are either undersized or only marginally functional as-is. Therefore, gun builders oftentimes must open ports according to the configuration of the gun and its intended use. Opening a barrel’s gas port is not difficult, but knowing how far to open it is a critical part of the process. I measure every gas port that comes across my bench and cross-reference it with a database of the 1000+ barrels I have previously measured to ensure that the size is appropriate for the length, caliber, gas system, gas block type, planned suppressor use and bolt carrier/buffer system weights.

Well, he’s a better mechanic that I am, he has a world of experience, and he has tools that I don’t.

Other than that …