Marushin Ruger Mk1 Bull Barrel

I always liked the look of these and ever since I got a chance to fire a real one when I was over in the states some time back I wanted an Airsoft version. Compared to the other handguns I fired this was amazingly easy to handle, pointed very naturally and the low recoil made for extremely accurate rapid fire. While a pretty anemic round compared to centre fire cartridges I figure that a couple or three .22 long rifle rounds would take the fight out of most people and a shot to the head would likely ruin your day.

That said, I finally managed to blag a stainless bull barrel version off one of the forums; a Marushin which has all the right trades and looks pretty cool. The gun is essentially full plastic but the sights are metal with target type front sight and an adjustable rear sight. I didn't get a manual with the gun but it's simple enough to figure out and a quick google supplied said manual and take-down guide.

Overall the gun looks good; I like the bull barrel and the trades are pretty good - despite the 'MADE IN JAPAN BY MARUSHIN' bit. The fit of the external plastic parts are pretty good and the fact that the receiver, barrel and cocking lever/thingy are separate actual adds to the realism. The metal rear sight had a lot of play but some strategically place aluminium tape has firmed it up and, although the blade can still be moved slightly back and forth, it's orders of magnitude better. The trigger pull is long and heavy as is expected of a non-blowback gun but not unduly so. There's a bit of slack before the trigger engages and a very slight roughness just before it releases the hammer. No big deal and I'm sure I can improve it. 

However, give the gun a shake and it rattles. Not quite like a set of maracas but not far off :) Only kidding but it's annoying enough to me that something needs to be done and, since these are moving parts, aluminium tape is unlikely to cut it. Do bear in mind though that for most people it's absolutely fine; I annoy easily. Out of the box the gun perform flawlessly and I can't fault the overall quality.

Taking the gun apart to it's main components is straight forward and dismantling it further is pretty easy as well. It breaks down to six main parts; the bull barrel, the slide, the inner barrel assembly, the cocking lever, the main spring housing and the grip. The grip contains three sub-assemblies which from back to front are the hammer and safety, the trigger mechanism and the loading lever. The gun works by simultaneously cocking the hammer and pulling back the inner barrel assembly to load a bb when the trigger is pulled. There is no hammer sear and the hammer is released simply by pulling the trigger all the way back. The safety works  by engaging a notch in the trigger bar preventing the trigger form being pulled. I'm not sure if the hammer is locked when on safe but since it's completely internal it is unlikely to be able to activate the magazine release valve without the power of the mainspring behind it. Putting it back together from completely stripped is slightly more challenging but three hands are not required and it goes back together with little trouble.

Obviously, the whole point in taking it apart was to iron out the niggles and improve what is already a decent bit of kit. My main task was to polish all the moving bits that came in contact with other bits - moving or otherwise. Having done that it was pretty clear that the hammer tolerance was generous and the main cause of the rattling but due to the way it's designed no improvements came to mind. The trigger take-up slack was dealt with by inserting a small square copper shim where the trigger meets the loading lever mechanism and a standard 0.1mm gearbox shim sorted most of the side to side movement - which to be fair was minimal but that's just me. It improved the trigger no end with a smoother pull, and no sign of the slight roughness just a crisp release. However, it did have the effect of not returning far enough to to engage for the next shot which was a bit of a pisser. Much head scratching later I was about to dismantle it to remove the shim when I decided to see if inserting the magazine would make any difference. It did. The gun worked flawlessly. Essentially, when the magazine is in the trigger bar is prevented from dropping the fraction of a millimetre that prevented the trigger reset.

I haven't chronoed it yet but from all the indications I've come across is that it runs hot. I'll see what it does on Ultra gas and drop to 144 if it's still over 350fps. Overall, I'm quite delighted with this while the silver finish isn't exactly skirmish friendly I can see me using it anyway.

The photos this time aren't mine and the qudos goes to k.a. on the Zero-In forum that I bought it off of.