The rifle also came with three cheesy hand guards that I tried on, but didn't like. They made the grip area too fat, and they rattled a bit. I think I'll just use some ladder rail covers instead. While trying to remove the Troy covers, I accidentally broke the little retainer tabs. After getting them off the weapon, I pitched them. It was a nice thought, Ruger, but you should just send the weapon with the ladder rail covers instead.
front and rear iron sights (BUIS). These are expensive sights (about $100 apiece) and they are great. Of course, Ruger couldn't help but make it so the bad guy knows just what gun killed him by having their name engraved on the front of the sight mounts. Clay pigeons, steel targets, and soup cans beware! A Ruger is bearing down on you! Actually, I really like the HK style front hood. It helps me better align the sights than the flared out standard AR sight does. Adjustments should be easy enough. Ruger sends a Troy Industries sight adjustment tool with the gun. It's not an expensive tool, but it is a nice addition. No need to use a cartridge tip to adjust the front elevation. Apparently, you can adjust the windage on the rear BUIS as well. Overall, I'm a fan of these sights. They have a positive up "click" and they don't budge once in place. To fold them down, you simply push the detent on the side, which releases them. To fold up, you simply push them up with your thumb. Simple!
The bolt carrier group is also chrome-lined, which makes it as easy to clean as wiping the carbon off. Of course, Ruger ships their guns to the customer filthy as hell, so I went ahead and stripped it down to clean it. At first, I was confused. The bolt itself appeared to be missing an o-ring. So, I looked at the exploded parts diagram just to be sure. Nope, no o-ring listed on the bolt. Guess it doesn't need it. I have to remember that this bolt carrier is a one-piece design and no gas is getting back to the bolt carrier group anyway.
direct impingement (DI) gun will depend greatly on this.
One of the things I really like about the SR-556FB is that mile of rail in front of the receiver. That's about the perfect length for me. I can get my hand up there really far and not feel all scrunched up like I did with the carbine length rail on my old AR15. I'm going to cover the sharp edges of the picatinny rail and install a stubby VFG up near the front for hand indexing. I might give the Magpul AFG a chance, but I wasn't too impressed with it on a carbine gun. It might be better on a longer rail. One thing is for sure: my wife wants a VFG up there because she holds onto it.
Since I had the gun o the bench, and finished cleaning and inspection, I went ahead and installed my Streamlight Scorpion X light, which used to take up residence on my RRA using a V-TAC light mount. I'll see how it goes up there. The gas regulator blows the excess gas out up there, so I may move the light back depending on how dirty it gets. I also hear the gas block gets rather hot on these short stroke piston guns. We'll see how the polymer mount holds up there. If it melts, then I know I need to get a metal one.
As for optics, I think I want to put a scope on it. Yeah, I know. Put an Aimpoint or an Eotech on there. Um, well honestly, I want some magnification. I know I can get a magnifier for an aimpoint, but I can also put a Trijicon scope on there for less money and still get the same result. CQB capability might suffer, but I don't know. I seem to have no problem using my 4x scope on my Ruger 10/22 in the house.
So that's my initial impression. I know this entry was a little pic heavy, but I had a hard time finding any close up pictures online, so I hope that my contribution helps out anyone who wants to see some semi-okay pictures of the gun. I plan on getting some really high quality photographs when the weather gets better, but until then, you can deal with this. Enjoy!