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Posted by ミリタリーブログ  at 

2012年04月20日

Adcor Bear 5.56×45mm


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“Brown Enhanced Automatic Rifle” featuring an advanced piston hybrid system!



The Adcor BEAR was designed for the purpose of upgrading the basic infantry weapon. The BEAR—shown here with a SureFire M900V vertical foregrip and Trijicon ACOG—surpasses a conventional operating system by utilizing a unique gas/piston hybrid that builds on the strengths of each system.


At first glance the Adcor Defense Brown Enhanced Automatic Rifle (BEAR) look likes a standard AR-15, but if by second glance its enhanced features have not jumped out at you, then you need your eyes examined. Piston systems are fine and good, but the BEAR is designed to compete in a future military rifle improvement program, the BEAR is not a conventional piston system—it is a hybrid.

The BEAR system takes the best of a variety of the other systems and builds on their strengths. It a modified AR-15 bolt carrier, with the most noticeable difference being a long rod attached in place of gas key. The appearance of the BEAR is reminiscent of the AK-47 bolt group. The end of the bolt rod fits into a short tappet near the muzzle of the rifle that receives the force of the exhaust gases. The tappet is propelled back sharply for a very short distance, and this movement pushes the bolt rod backwards allowing the bolt to unlock and recoil under the kinetic energy of the discharging cartridge. All of the hot exhaust gases stay in the front of the system and out of the receiver, which is the big benefit of a piston system. The BEAR overcomes the adverse mechanical influence of the piston slap and subsequent carrier tilt by using the length of the bolt rod as a mechanical guide, thus keeping the bolt from from wobbling around inside the receiver. At its core, the system is a “short-stroke” piston rather than the short-stroke system more commonly seen in AR piston variants today.



BEAR’s bolt carrier and key design requires two pieces—carrier and piston key—as it would be impractical to manufacture the bolt carrier and long piston rod as single piece.


The bolt carrier and key are is made by Adcor. The BEAR design requires two pieces—carrier and piston key—as it would be impractical to manufacture the bolt carrier and long piston rod as single piece. With more common short-stroke piston systems, the bolt carrier and key are one-piece. This design is touted to be as superior to the Mil-Spec carrier, where the key is screwed onto the carrier from the top and then the screws are Loctite and pinned to prevent them from backing out. In the world of do-it-yourself kit-built ARs, there are concerns that if the bolt carrier is of inferior production the screws can back out, which may cause the weapon to jam very soundly. This is generally not an issue with factory-built rifles like the BEAR, where assembly jigs and precision tools are used.



The dustcover is slightly modified to function with the BEAR wiper system, which is fitted with springs that push the wiper outwards and fill the ejection port, effectively sealing it to significantly reduce the infiltration of debris.


The gas system can be adjusted by turning the regulator valve located in the forward part of the gas block. The gas regulator value is available with either two or four positions of adjustment. The four-position valve is more military oriented. It can be opened or closed down for suppressors or running a very dirty weapon. The in-between positions are for best function depending on ammunition type.



The gas system can be adjusted by turning the regulator valve located in the forward part of the gas block, which is available with either two or four positions of adjustment.


There are many flavors of operating systems for the modern rifle. The original AR-15 design is the direct-impingement system, where gas is vented from the barrel via a tube and directed against the key to force the bolt rearward. Direct impingement is simple and very lightweight.
Its principal disadvantages are that the gases and the associated debris are vented inside the upper and lower receiver, as the heat of the gases reduces the life of some metal components and critical lubricant is dried out.

With the short-stroke piston system, a piston rod is a separate component. When gases are exhausted from the barrel they strike the face of the piston rod. The rod is pushed violently towards the bolt. The striking of the bolt carrier by the piston rod starts the bolt backwards. The advantages of the short stroke systems are that it is lightweight and it is cleaner as gases do not enter the receiver. However, a potential disadvantage is related to the mechanical forces acting on the bolt carrier. The movement of the bolt carrier can “tilt” and may be the cause for premature wear and damage to the bolt and upper receiver.

The AK-47 is a familiar example of the long-stroke system. The gas piston is attached to the bolt carrier and extends far in front of the bolt and the face of the extended piston receives the blast of gas directly. It is a very simple and rugged system; however it is also heavier, both in terms of weight and as the mass relates to momentum and the functional effects on the shooting characteristics of the rifle.

Close inspection of the dustcover reveals that the detent is located at the rear of the narrow flap, unlike the Mil-Spec flap with the catch in the center of the long side. It is there because of Adcor’s unique port dust wiper, made of engineered polymer and attached to the side of the Adcor bolt. The wiper is fitted with springs that push the wiper outwards and fill the ejection port, effectively sealing it. When the bolt moves, the wiper is slightly depressed, and during the bolt’s cycle the wiper remains in contact with the interior surface of the upper. This keeps dust and sand from infiltrating into the upper receiver around the bolt. Adcor’s wiper is intended to significantly reduce the infiltration of debris.



The weapon’s versatility is further evident in the fact that the Adcor charging handle can easily be swapped out and placed on the opposite side for ambidextrous capability.


At the rear of the upper receiver is the standard charging handle. However, Adcor’s extended bolt rod has another trick up its sleeve—another charging handle and forward assist handle. If you are familiar with the Heckler & Koch series of rifles (G-3/HK91, HK93, HK53, MP-5) then you are aware that their charging handles are located alongside the barrel forward of the receiver. As the bolt piston rod is attached to the bolt carrier, Adcor took advantage of this and attached a second charging handle to the rod.

Using the charging handle to cycle the bolt no longer requires shooters to more radically shift their shooting position in order to operate the traditionally charging handle. Since the Adcor charging handle does not reciprocate, the shooters are able to place their hand on the forend without concern of injury. The Adcor charging handle is used to charge or clear the action. It can also be used to lock the bolt open; however, that still requires manipulation of the standard bolt catch.

Adcor does not stop there, the charging handle can easily be swapped out and placed on the opposite side. Adcor leaves the traditional AR upper receiver’s charging handle so that shooters can easily operate whatever system with which they are comfortable.



While the rear of the upper receiver has a standard charging handle, Adcor’s extended bolt rod carries a non-reciprocating forward charging handle, no longer requiring the operator to radically shift shooting position in order to charge the weapon.


The BEAR upper offers everything the military could want. A simple change to existing rifles and the military would be well served with this enhanced rifle. The same upper or even complete rifle is also available to the civilian shooter, complete with the same level of features and convenience. If you as a shooter have grown beyond the standard AR, then the Adcor BEAR may be your best choice.

By Jerry L. Cannon, Images by Sean Utley


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Posted by echigoyaworks  at 21:36Rifles

2012年04月20日

ETA Devastator 12 Ga


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Elite Tactical Advantage’s highly capable and revolutionary tactical shotgun!



The ETA Devastator is truly revolutionary for the 11-87 design, incorporating a folding stock and radical rail system to this popular platform. Seen here equipped with a Burris FastFire II Red Dot and Insight Tech-Gear M6X Laser/Light.


Having long been a fan of the shotgun platform, I’ve taken the opportunity to test a variety of scatterguns throughout my career. Starting life as a dyed-in-the-wool pump shotgun guy, the move to semi-automatics was made in earnest about 10 years ago. As they became truly reliable, all the downsides just seemed to disappear. Clearly there are some operators out there that are as “fast as the auto” with their pump gun, but not me.



The ability to have it cycle as fast as the trigger is pressed can be advantageous on an entry or at close range. With the correct ammunition they also seem to add some credence to the pseudo-science of the “one shot stops.” All of the discussions as to the terminal ballistic performance of rifles, pistols and submachineguns just make most shotgun guys chuckle. The number of cases where the suspect was double-tapped with buckshot at close range and failed to stop are just about non-existent. With the advances in ammunition it only gets better. Buckshot patterns that are under 5 inches at 25 yards are common, so the need to change ammunition is reasonably limited. With all the rifles that go through these hands, the semi-auto 12 gauge is still my go-to-gun. A short-barreled semi-auto with a small red dot, pistol grip, and side saddle is within reach to this day.



The folding stock allows operators to bring serious firepower for covert assignments as well as fighting from a patrol vehicle.


One of the first short barreled semi-auto shotguns deployed for entry on our LE team was an 11-87 made by Scattergun Technologies. It was one of the last ones made prior to the sale of the company to Wilson Combat. Once it was tuned up to use the ammunition we used most, it ran fine, as long as we used that ammunition. Running low-brass practice ammunition could be a bit of a problem as compared to the duty ammunition. Eventually, we benched them and followed the popular move to submachineguns.

By Dave Bahde, Images by Steve Woods



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Posted by echigoyaworks  at 18:26Shotguns

2012年04月20日

TM Scar Gearbox Disassembly

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Following are step by step photos of how to disassemble your Tokyo Marui Scar gearbox. This is the second part, the first part is the takedown which is blogged here:

http://echigoyaworks.militaryblog.jp/e289188.html

The gearbox shown here.


First we need to remove the recoil assembly. First we need to remove these 3 screws to remove the fornt part of the recoil assembly.


After removing, slide recoil guide out and then remove the recoil block on top of the gearbox as shown in the direction.


Now to open the gearbox, remove these 4 screws using a torx driver.


After removing them, there is still one more screw hidden. First pull the wires out and rotate the wire cover as shown.


Now you have access to this screw which is holding the bolt-stop assembly, remove it. Make sure to remember how it was installed.



Then this is the last screw that holds the gearbox together.


And it is done, gearbox revealed as shown.



Reassembly tips.

This notch on the recoil guide will held by the screw that goes in here.


Reassemble first the left side of the recoil guide to put it back in place before inserting the recoil guide.


Then insert the two recoil springs and the buffer in the back.



And that's it. If you have questions send me an email.



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Posted by echigoyaworks  at 12:24DIYs

2012年04月20日

M26 MASS Shotgun

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M26 MASS shotgun Issued to members of 101st Airborne Infantry Division



The 502nd Parachute Infantry Regiment (a.k.a. 2nd BCT/101st Airborne Infantry Division) is the first unit to field the M26 Modular Accessory Shotgun System. According to a story on ClarksvilleOnline.com, Strike Brigade’s engineers and military police with H&H were trained up over three days by members of Picatinny Arsenal’s PM Soldier Weapons after a ceremony held Feb. 7, 2012, at Ft. Campbell, Kentucky.

The MASS is designed to aid in faster transitions from the shotgun to the rifle during breaching operations, but has other applications including less-than-lethal rounds. It mounts beneath the barrel of an M4 and can be attached to a stock and used as a standalone shotgun. It is a 12-gauge system and has a five round magazine.

By Rob Curtis, miitarytimes


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Posted by echigoyaworks  at 09:02Shotguns