[RC20]

Just got done with the first firing session with the XCR.

My brother reloads the 5.56, so we were recovering the cases.

At the mouth of the case, they were badly dented, dented moderately at least 50%-60%. As it was shucking them good and no cycle issues, I dropped the adjustment down to 1. That helped, but did not stop it (fewer dented and not as bad, but still 40% at least).

Just read that S was the lowest setting and can try that still. Any ideas on this?

 

[Jack A Sol]

go thru the gun and check correct tightness of every bolt and nut. locktite all but the barrel nut. disassemble and check the gas block too. where is it denting it? in the mouth or side of body? some side of body denting is normal and shouldnt affect reloadability or function. Make sure that the ejection buffer is on properly too.

 

[RC20]

At the very fron lip of the mouth.

 

[aziator]

Make sure the gun is completely done with the break in period before adjusting the gas. Mine dents a little every now and then but nothing that stops me from reloading it.

 

[TerraShrewsbury]

mmmyeah... you'll want to keep that gas setting on 4 for the first 300 rds.

 

[RC20]

Not to be argumentative, but I am a mechanic/technician/engineer. I am not satisfied with just statements, but want to know the underlying reasons (or operating principles) of those, so I can determine if they apply to my specific situation, as opposed to general practice.

I saw the recommendation, but its cycling without any issues at all, and denting the brass (some badly enough its questionable for re-use.

Question is, if its firing fine, is there any reason not to back off on the gas setting to save the brass?

My understanding is that the full pressure is to ensure it cycles properly and needed full pressure to do so during the break-in period. We have thrown a wide variety of factory and reloads at it (60 rounds roughly) and no indication of failure to cycle at all.

Some was 20 year old stuff in pretty grim condition, and we were curious if it would handle it, which it did with no issues at all. Extremely solid.

 

[TerraShrewsbury]

You can fire it on whatever setting you feel necessary. Typically setting four is useful in providing the kick required to cycle hard enough to wear in all the new parts. If your rifle is working fine on 2 or 1, go to it. We only offer recommendations. It is, in the end, up to your discretion and whatever works best for you.

 

[Deltaview]

RC20, are you sure the dents were caused by the case hitting something in or on the rifle? I experienced a similar problem shooting on an indoor range. An XCR with the new gas system on setting 4 has a very forceful ejection. It will throw brass 25-30 feet. Mine was throwing the brass against a a wall on my rignt hard enough force to ding some of the case necks if it hit the wall just right. The top of the case neck is not that strong on fired brass and will dent easily.

 

[ny32182]

I get some dented case mouths as well on all gas settings, not nearly as many as you are stating though.

I would think it would have to be one hell of a smashed case mouth (dent going all the way down into the shoulder?) before the case would be unreloadable. Can you post some pics of the dents?

I'd guess that removing and replacing the ejector may change its position ever so slightly enough to change the exact angle on how the cases come out of the ejection port. That might help.

Also, you might try a different caliber ejection port buffer. I believe there is one guy here who runs a 6.8 buffer with 5.56 or vice versa to change the angle at which the brass is ejected. If it is indeed smashing mouths on the side of the receiver (ala FAL), I think what you are looking to do is change the geometry of the ejection somehow.

 

[Jack A Sol]

if your ejector is loose then if might be ejecting it a smidge early and denting the mouth

if other bolts are loose then it may be causing abnormal ejection as well.

understand now?

check and locktite your bolts. complete the breakin at gas level 4 unless it is ripping off rims or something. the XCR requires a break-in period during which it will have issues. a good thing to do might be to do a 3-4 mag "mag-dump" and heat the gun up real good. check your bolts first.

the XCR smooths up considerably the more you shoot it. if you cant afford to shoot it or just dont get out enough to do so, then you can expect the gun to be a disappointment to you. go back to the AR or AK and be happy. the XCR is a gun for people who like to shoot, can operate a gun and understand its maintenance and operation, and need a gun with capabilities beyond the AR or AK. It is not a gun for the conscript or safe queen operator. the most successful XCR owners shoot thier gun frequently and know how to run it.

The XCR is a new design. As such you as a first adopter have signed on to be part of the test pool. you may have issues that no-one else has had. as a community we will make this gun a solid dependable platform. we depend on your experience and input as much as you do ours. be patient and work with the design, we have a great company backing it.



jack

 

[va_plinker]

Gee Jack, you've guilted me into going out tomorrow to shoot some!

I've gotta stack of mags to empty!

 

[Jack A Sol]

Gee Jack, you've guilted me into going out tomorrow to shoot some!

I've gotta stack of mags to empty!

atta boy!! ;D

 

[gunner69]

Got to agree with Jack, check the Ejection Buffer first. I might get a dented mouth but it is rare. :2cents:

 

[WaltherP88]

In what field are you a mechanic/technician/engineer?

 

[tk]

RC,

I noticed this on a couple of the cases from mine, as well. But the dented ones are never in the big pile that is ejected 20 feet ahead at 2 o'clock; they were always the ones that bounced off a post at the range where I shoot.

tk

 

[RC20]

In what field are you a mechanic/technician/engineer?

Commercial/light industrial mechanical systems. More or less takes in Refrigeration, Boilers, Switchgear, Generators, fire pumps (diesel and electric), computer controlled systems that run the above unit, various fire suppression systems (water sprinkler and foam), glycol mix system, pumps and fan systems, conveyors (mostly control and motor end), fuel tanks, oil water separators and so on.

Some like the backup generators are rated as industrial type, as is some of the refrigeration, so there is some cross between heavy industrial and light industrial (if it works and is less expensive heavy would use it, or in our case, some equipment only comes in heavy and we use it)

 

[RC20]

RC,

I noticed this on a couple of the cases from mine, as well. But the dented ones are never in the big pile that is ejected 20 feet ahead at 2 o'clock; they were always the ones that bounced off a post at the range where I shoot.

tk

Wide open area in front of the shooting bench,

 

[RC20]

Got to agree with Jack, check the Ejection Buffer first. I might get a dented mouth but it is rare. :2cents:

All exterior parts were checked, screws checked, and all tight before first firing.

I took it down this weekend, and all is fine isnide, i.e. injector bolts

I did find brass had coated the end of the ejector port hex head screw , it has about 3/32 more thread than needed and extends into the receiver.

 

[RC20]

Latest on this issue:

I setup a square plastic bucket as a brass catcher, and we put another 40 rounds through it. With a bit of positioning, the bucket caught it all. Looks weird, but no affect on shooting as I am using a rest.

Setting was at S. Some minor dents on some, but nothing as bad as previous.

Keeping in mind we are firing full power hand loads (mostly, and what isn't is full power old stuff). No failures to cycle at all.

 

[Bohemus]

I suspect Delta View has got it nailed, in my case any way. Took the XCR out for the its first session this past Friday and noticed the same thing, the brass was dented to hell @ the mouth. Thought about it for a second or two and recognized that yeah the ejected brass was hitting the sound wall next to me with such force as to dent the crap out of them. The bane of living in the city: indoor ranges. Damn convenient they are though. All I can say is my weapon functioned flawlessly. Other than a guy whining about getting hit by a little copper jacket shrapnel it was a great time! Ye Ha!!!!!!