The Real "XM177E2"
After the M16 series was introduced and adopted into the U.S. air force in late 1964, it was decided that a smaller version was desirable for flight crew protection and so, a submachine gun version was developed in the mid 60's, deemed the AR15, XM177, it featured a collapsible stock and a 10" barrel with a flash suppressor, but it lacked the forward assist that the M16A1 series featured, as the Air force technicians felt the feature was unnecessary due to improved cleaning and ammunition.
Later, the U.S. army adopted the XM177 "submachine gun" after making some adjustments to the basic air force design, due to reliability problems with the 10" barrel. Army technicians slightly lengthened the barrel to 11", improved the flash suppressor design (which slightly changes the sound of the guns report, due to the internal baffles in the" flash suppressors" design) Also, the lengthened flash suppressor along with it's special washer/ring that was added to the rear of the flash suppressor, which allowed grenades to be fired and adding the forward assist, due to the army's changes, the nomenclature was changed to XM177E2.
The Marushin XM177E2 (kit)
The Marushin XM177E2 was originally produced as a fully assembled modelgun, but possibly due to Marushin trying to keep the prices down, they started offering the XM177E2 and the M16A1 in the kit versions.
The original kits where not painted, and Marushin originally included a can of black paint, but thankfully, the later kits are all factory painted with a realistic looking black finish that is realistic and is pretty durable.
Thankfully, all of the trademarks are present and are faithfully reproduced.
The internals are all nicely reproduced too, with all of the parts being faithful to the original M16 series of weapons in design and execution.
All of the parts in the kit (with the notable exceptions of the stock, the forearm and the flash suppressor) are either Zinc or steel. In the earlier versions of the Marushin XM177E2 kit, (and the factory assembled versions) the flash suppressor was die cast zinc.
Once again, the instructions are in Japanese, unlike the days before 1988, where the collectors armory in association with Marushin (and other Japanese modelgun manufacturers) often would have included copies of the instructions translated into English in the kits.
However, the illustrations are excellent and to the point, as with the other Marushin model kits that I have had. In fact, I have Marushin factory assembled modelguns that included kit assembly instructions with them!
The assembly is slightly slow paced though, due to small and quite numerous parts (springs, E-clips, pins etc.) but the assembly is not truly difficult.
At first, the order of the bagged up parts in relation to the assembly steps was slightly confusing, due mostly, to the fact the bags are not numbered or labeled.
Be very careful when opening the small parts bags, as there are some very small springs and pins in them and it is very hard to replace any of these components! (unless, of course, you live in Japan.)
The butt stock assembly to lower receiver is and was , perhaps the worst and the most troublesome of all of the kit's assembly steps! Due, mostly, to the threads on the butt stock tube being "flat" while the lower receiver threads are sharp. This causes an interference fit problem with the tube refusing to thread into the lower receiver. This problem in my case, was fixed by using a small triangle shaped needle file, to re-cut the threads on the tube. This was a very time consuming operation, and it took me hours to obtain the right fit. Hopefully, the second XM177E2 kit that I have will be easier to assemble in this regard!
The supplied magazine is a 20 round Marushin manufactured, stamped steel magazine. Unfortunately, (at the moment) Marushin no longer produces the 30 round version and the magazines are different dimensionally than MGC and real AR15 (or M16) magazines so, finding a 30 round Marushin made magazine is difficult.
The construction of the 20 round magazine is typical of Marushin modelguns, with the body of the magazine being made of stamped heavy gauge sheet steel, spot welded and blued .
The follower in this case is cast out of Zinc and is shorter in length than a actual M16 magazine follower due to a spot welded in cartridge spacer/ramp, this spacer is necessary because of the cartridge length difference (no bullet) as the magazine has basically the same length as an actual AR15/ M16.
When the last shot has been fired, the follower is supposed to lift up the bolt-stop and hold open the bolt. However, since the front of the Marushin follower lacks a support leg, it can often tip downwards and slightly forward. It does this often enough to allow it to miss the bolt stop. Also, since the magazine spring is considerably weaker than a actual M16 magazine, it does not have enough pressure to properly activate the bolt stop.
The Marushin produced 30 round magazine is far different than the 20 round version as the magazines body is constructed out of aluminum .
The 30 round magazines feed lips are quite similar to the actual M16 magazines so it is hard to tell the difference between them!
The actual M16 magazine is slightly smaller than the Marushin magazine so interchange is somewhat difficult. (although, it has been done) Also, the magazine catch hole is larger and slightly taller in comparison.
I replaced the original Marushin black abs follower with a green- fiber reinforced, current production M16 follower that features an extra "leg" that stabilizes the follower for better operation.
The Marushin designed, M16 series cartridges consist of 3 parts, the base with female threads and the firing pin, the main body with male threads and the piston the basic cartridge is made out of brass with the exception of the firing pin which is made out of steel.
Properly loading the cartridge is the key to a good firing simulation as the modelgun relies on attention to reducing friction in all areas especially in the cartridge, as the piston must move freely when the cap body or the gasses impinge upon it allowing the caps full energy to act against the bolt or slide.
If the friction areas are not properly addressed, the action may work sluggishly or not at all, reducing the enjoyment of the firing simulation.
To properly load the Marushin cartridges, all of the cartridge parts must be clean especially the main body section as the cap and the piston slides on the inner walls of this part. Also, the firing pin in the cartridge base must be free of corrosion, rust, dirt and cap debris.
You will probably notice that the firing pin in the cartridge base, is considerably longer than any other Marushin firing pin, as this is intended to be a part of a solution to the gas leakage problem at the cartridge base. Earlier experiments to combat the gas leakage problem, came up with the "intense sheet" this was simply a thin rubber washer that you put in the base of the cartridge. This was intended to seal the threaded joint between the base and the main body also, an O-ring was tried to achieve this same result however, these solutions had their own problems.
The solution that Marushin developed was very well thought out, the firing pin was lengthened so a used cap body (open-ended side up) could be placed on the pin. This would serve as a gas seal that was centered in the cartridges main body by the pin, yet still allowed the cap to reach the firing pin. This idea is illustrated in the instructions provided in the kit.
After the components are clean and dry, using a light grease and a Q-tip, (Vaseline will probably work however, try to use grease with a somewhat higher melting temperature ) lightly cote the inside of the cartridges main body then, insert the piston into the main body (with the chamfered side facing away from the base) and then insert the cap with the red/blue phosphorus filler facing towards the base/firing pin and then, using the provided abs plastic tool (the short side on the tool is intended to set the caps to the proper depth and the long side of the loading tool is for pushing out the expended caps and the piston) push the cap down into the main body section to the proper depth.
After the caps depth has been adjusted, select some previously fired cap body's preferably, the ones with holes in their centers (caused by the detonator or firing pin) if the hole is not present select a punch of proper diameter (the center of the cap is thin in this area as it is, so it is quite easy to perforate the cap there) once the hole is made the cap body they are ready to be used as a gas seal. Depending on the diameter of the hole in the cap center, the cap body can be installed either in the cartridge main body, or the base section on the firing pin with the open section of the fired cap installed facing the un-fired cap. This part is the tricky one as the mouth of the fired cap is the diameter of the main body inner diameter (7mm) If the fired cap body has a small hole in it's center it is best to place it on the firing pin in the base, as you will just push the fired cap body further into the main body of the cartridge which will cause other problems. If the hole in the cap is fairly loose, it can be installed in the cartridge main body as the firing pin won't push it in further. If all goes well, you have completed one cartridge now, just 29 more to go!
The firing simulation:
I used the 30 round magazine in this video as it worked a little better than the 20 round version, plus it looks better and holds more cartridges. I prepared the cartridges using care to be sure that I put caps and pistons inside them! It is amazing that it is possible to forget to place caps into the cartridges, as I have done that before!
The caps that I used in the video are the older (and as far as I know, out of production) Marushin brand caps with the red phosphorus filler. They where packaged in the old style flat box. Although the caps that I used where probably 15 years old, they worked great and didn't cause any trouble.
The first rounds fired and ejected fine but after 15-18 rounds, the last shot hold-open feature for some reason operated and held the bolt open! (I think that the spring that the hold-open piece uses to prevent accidental engagement is weak) So, after a few seconds I discovered this and after I corrected the problem, I fired the remaining rounds in the magazine with no problem.
I fired a total of 35 rounds for the video. 30 rounds full-auto and 5 rounds semi-auto although, it fired the last 2 rounds full-auto.
My XM177E2 was assembled as it came out of the box with minor casting "flash" removal but no other work was done.
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