Ruger SR556C at 5,000 rounds. A Photo Essay

[UWone77]

No suppressed shooting?

I really enjoy your threads usbp379, you stay on top of your long term projects... unlike me. It's impressive your Ruger exhibits none of the carrier tilt I've seen in other Rugers. Those must have been earlier models.

[usbp379]

Thanks!

No suppressed shooting with this model since it has an integral flash hider that isn't compatible with my AAC can.

This rifle is an early model but I think it is one of their first with the redesigned bolt carrier. The first Ruger bolt carriers had a traditional GI profile and many of those early guns showed some pretty good scuffing in the buffer tube.

The later bolt carriers have a flared tail that helps support the back end where it meets the tube. Ruger also took the novel approach of removing some of the raised contact points that run along the sides of the carrier. They say this allows the carrier to "float" inside the upper and allows it to better align itself with the buffer tube.

[nobodyspecial]

I need to find out if my dads has the flared BCG. He doesn't have many rounds through his, though. Are the all integral flash hider?

[usbp379]

I need to find out if my dads has the flared BCG. He doesn't have many rounds through his, though. Are the all integral flash hider?

Only the SR-556C and CLA models have the intergral flash hiders but they're also the only models with the lighter fluted barrels.

[usbp379]

I am now at 8,500 rounds as of today's date and suffered my first parts failure. At about 8,400 rounds the dust cover detent failed. The nodule had been loose for a long time but the staking finally broke loose.

[DUX]

@usbp379: That is outstanding!

[usbp379]

I should have been done with this two years ago. Sorry it has taken me so long to get back around to this.

[Jerry R]

At about 8,400 rounds the dust cover detent failed. The nodule had been loose for a long time but the staking finally broke loose.

That's actually very interesting. I am "assuming" the dust cover was not closed after every round was fired. That means the round count for that particular part would not be 8,400; and probably significantly less. If you closed it after every magazine, and used 30 round magazines, it would only be 280 cycles. I would guess less than that. Do you have any WAG of how many times the dust cover was popped open by the BCG?

[usbp379]

I am in the habit of swiping the safety on and closing the dust cover when the gun comes off target. Depending on what I'm doing I might run some short drills where I'm only shooting one or two rounds and then closing the cover. Or sometimes I might shoot half or ¾ of the mag before closing the cover.

The scallop in the Ruger's bolt carrier is slightly shallower on the bottom than that of a GI carrier so the dust cover detent had a small peened spot that was getting whacked as the carrier came back and popped the cover open. That might have been what jarred the detent loose.

But it could have been a defective cover to start with. There was a thread on arfcom several years ago where guys were reporting failures of this style with DI guns and it looked like whoever the main supplier is sent out a batch of covers with inadequate staking.

[Former11B]

Edit: Really didn't see how old this comment was before replying. No need to even keep it around

[Jerry R]

Thanks usbp379 - that makes a lot more sense.

[usbp379]

Just hit 9,000 rounds as of this morning. Nothing different to report.

I did get the gas block hot enough to melt my VTAC sling though. Oops...

[Joelski]

You don't need no stinkin' dust cover on that thing! The only reason you would need one is to keep all the crud from running out and getting filth on whatever it touches!

PS: Nice report! I'd say if your results are representative of what SR owners are seeing in general from their rifles, the gun performs as well, if not better than the so-called top tier guys. Hell, it probably costs SCAR owners pretty close to 5K all together to see that kind of reliability/round count, by the time you replace all the broken stuff and buy ammo.

[usbp379]

Hopefully I'll have this project finished up within the next couple of weeks. I'm anxious to see how hard it'll be to get the gas system apart.

Plans are currently to strip and photograph the rifle in dirty condition. This will be followed by a thorough cleaning and some additional photos.

After parts are cleaned and oiled I'll install a new dust cover. I'll also change the firing pin, extractor and spring and probably put in a new buffer spring. Then I'll keep on a'shooting!

[DeviantLogic]

Thanks for continuing to journal the progress. It's a real testament to the SR556 platform.