I recently purchased this gun with the intent of converting it into a full metal M733. Though I was successful in completing this task, there were some oddities with The XM177 that made the task just a little more difficult.
This "mini review" is meant to address these oddities as well as some other questions that I was wondering about (and couldn't find a good answer to online). As I currently do not have access to a chronograph, I will not be including performance stats at this time (though I will try to add them if I get the chance.)
Overall appearance/Build QualityUpon receiving the package, the first thing that surprised me was the box itself. Not what was on it (I honestly don't think 99% of airsofters care about what the box looks like) but rather the size of it. The box is the same size as the box for my full length M15A4 rifle.
The gun is of the same quality construction as the other rifles in the CA M15 line, with a full metal receiver and the fiber reinforced polymer forearm grip and stock. The receiver is emblazoned with the same trademarks as the rest of the ArmaLite line, however, below the ArmaLite logo the receiver is engraved with "CARBINE XM177 E2" and below that "M15A1" The serial numbers on these rifles are very low, with mine being 180.
The receiver is painted a medium grey color instead of the standard black on most CA ArmaLites. The upper has a fixed carry handle with the A1 type rear sight (adjustable for windage only). Similar to the rest of the ArmaLite line, The XM177 has 2 separate sighting apertures to choose from, however for some strange reason they are both the same size (the normally smaller of the two apertures). The upper has a forward assist knob that is more of a triangular shape as opposed to the round one found on later models. The upper does not have a case deflector. Finally, the ejection port door has a semi-gloss black finish.
The lower is more or less like the rest of the ArmaLite line, however, the bolt release rattles more than it does on my A4 rifle. Also the grip is the old A1 style, without the bump between your middle and ring fingers.
The adjustable stock has 5 positions and is smaller than the one found on the rest of the CA carbines. It is made of similar material and operates in the same fashion.
Oddities/differences from other CA ArmaLitesApart from those already mentioned, there are a few other differences to be found in the XM177. These include:
1: The XM177 has a mock gas return tube running from the front sight to the receiver.
2: CA elected to glue on the flash/sound moderator instead of using a set screw like the other rifles.
3: The inner barrel on the XM177 goes into the flash/sound moderator, necessitating a new inner barrel if you wish to use a different flash hider.
4: For some reason, aftermarket magazines don't feed as well in the XM177 as in the rest of the ArmaLite line. (this can be fixed with some tape in the back of the magwell, however the mags won't drop free when the mag release is depressed)
5:
MOST IMPORTANTLY the forearm on the XM177 has a significantly smaller inner diameter than other ArmaLites. This means that standard M4 batteries will NOT fit in the XM177...special batteries like the ones in the link below are required.
http://www.wgcshop.com/pcart/shopper.php?itm=SYO-96-1100LR_srch_lr300
