AR15.Com Archives
 Is the way in which the barrel is attached to an XCR really that fragile?
ds3_09  [Member]
2/8/2010 4:22:47 PM EST
I read this alot in discussions about this rifle. People who have something against it often bring this up.

I have one on it's way to me. I'm just curious if this is really an issue or just over played?
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ShogunOfHarlem  [Team Member]
2/8/2010 4:59:24 PM EST
It's not that it's fragile. It just might back out after shooting a lot (if not torqued properly).
yarbsea  [Member]
2/9/2010 6:11:29 AM EST
It might back out?

As simple as a FSB's taper pins might walk out of an improperly mounted ar-15 FSB!

Gimmi a break people - you can't claim a product has a downfall if it is IMPROPERLY maintained. Torque as required and it is a non-issue...retarded at best guys!
ShogunOfHarlem  [Team Member]
2/9/2010 6:28:48 AM EST
My SHTF fantasies don't involve me lugging around a torque wrench.

With AR FSB pins, you tap em in and forget about them. When shooting my XCR, I am constantly checking the barrel bolt. I am at 3100 rounds since I last torqued my bolt, so my confidence is still building with it. But it's something extra that you don't need to think about with an AR.
CarlAMG1  [Member]
2/9/2010 8:52:00 AM EST
Originally Posted By ShogunOfHarlem:
My SHTF fantasies don't involve me lugging around a torque wrench.

With AR FSB pins, you tap em in and forget about them. When shooting my XCR, I am constantly checking the barrel bolt. I am at 3100 rounds since I last torqued my bolt, so my confidence is still building with it. But it's something extra that you don't need to think about with an AR.



You don't need to carry a torque wrench to tighten the barrel. I have a 6.8 caliber conversion and switch barrels more than most ever would. I haven't had the barrel loosening on me. Get the proper size Allen wrench, tighten until snug, muscle out another quarter turn and you're set. This is such an overblown issue.



ShogunOfHarlem  [Team Member]
2/9/2010 9:28:09 AM EST
Originally Posted By CarlAMG1:
Originally Posted By ShogunOfHarlem:
My SHTF fantasies don't involve me lugging around a torque wrench.

With AR FSB pins, you tap em in and forget about them. When shooting my XCR, I am constantly checking the barrel bolt. I am at 3100 rounds since I last torqued my bolt, so my confidence is still building with it. But it's something extra that you don't need to think about with an AR.



You don't need to carry a torque wrench to tighten the barrel. I have a 6.8 caliber conversion and switch barrels more than most ever would. I haven't had the barrel loosening on me. Get the proper size Allen wrench, tighten until snug, muscle out another quarter turn and you're set. This is such an overblown issue.





I've used the method to tighten the barrel bolt without a torque wrench, just using a regular allen wrench on my first XCR. The barrel bolt would back out after a couple hundred rounds consistently. I eventually just used Red loctite on it which solved that.

I don't think the barrel retaining bolt possibly coming loose under hard use is something that should be taken lightly or brushed off. I think it's a design flaw that turns people off to the XCR. I've heard talk that Robarms has thought about doing something with the bolt, but nothing solid. Hopefully they do, as it would only make for a better weapon.

We didn't get the new trigger because people thought that the old one was suitable.
bolster  [Team Member]
2/9/2010 10:44:34 AM EST
I still haven't had either of mine shoot loose. Not saying it can't happen, but I think it's something that rarely happens.

The one person who did shoot it loose and posted about it didn't torque the gun after buying it "new" from a shop. I say "new" because the gas tube was dinged up where it meets the gasblock when he bought it, and the only way for it to have happened would be to have shot it with the barrel loose. I don't believe it left the factory that way.

If Robinson comes out with an upgrade that can be retrofitted to existing guns and completely locks the bolt, I would probably buy it because you can't ever be too safe. As it is now, I'm not really concerned.
CarlAMG1  [Member]
2/9/2010 10:56:41 AM EST
Originally Posted By ShogunOfHarlem:
Originally Posted By CarlAMG1:
Originally Posted By ShogunOfHarlem:
My SHTF fantasies don't involve me lugging around a torque wrench.

With AR FSB pins, you tap em in and forget about them. When shooting my XCR, I am constantly checking the barrel bolt. I am at 3100 rounds since I last torqued my bolt, so my confidence is still building with it. But it's something extra that you don't need to think about with an AR.



You don't need to carry a torque wrench to tighten the barrel. I have a 6.8 caliber conversion and switch barrels more than most ever would. I haven't had the barrel loosening on me. Get the proper size Allen wrench, tighten until snug, muscle out another quarter turn and you're set. This is such an overblown issue.





I've used the method to tighten the barrel bolt without a torque wrench, just using a regular allen wrench on my first XCR. The barrel bolt would back out after a couple hundred rounds consistently. I eventually just used Red loctite on it which solved that.

I don't think the barrel retaining bolt possibly coming loose under hard use is something that should be taken lightly or brushed off. I think it's a design flaw that turns people off to the XCR. I've heard talk that Robarms has thought about doing something with the bolt, but nothing solid. Hopefully they do, as it would only make for a better weapon.

We didn't get the new trigger because people thought that the old one was suitable.


I think it's interesting that some people seem to have this problem and others, including many who change the barrel regularly, do not. I've had my XCR for over three years and this was never an issue with either of my barrels. The comment about needing to carry a torque wrench is ridiculous. I don't know about a design flaw but if it's solved with some loctite fine then loctite away. It's an unnecessary step for my rifle.

Not sure on the comment on the trigger. We did get a new trigger because people, including me, weren't happy with the original. I had a Bill Springfield job before converting to the enhanced trigger.

ds3_09  [Member]
2/9/2010 12:01:18 PM EST
What I had read was that having one bolt is insufficient/weak. Like say drop the gun on the end of the barrel it might not fair well. I've never handled and XCR so I am just asking.
ShogunOfHarlem  [Team Member]
2/9/2010 1:07:18 PM EST
Originally Posted By ds3_09:
What I had read was that having one bolt is insufficient/weak. Like say drop the gun on the end of the barrel it might not fair well. I've never handled and XCR so I am just asking.


I've never heard of anyone ever actually breaking the bolt. It's pretty beefy, and I think it would take a lot more than a 4-5 foot drop.
TheOtherDave  [Member]
2/9/2010 1:19:06 PM EST
Originally Posted By CarlAMG1:
Originally Posted By ShogunOfHarlem:
My SHTF fantasies don't involve me lugging around a torque wrench.

With AR FSB pins, you tap em in and forget about them. When shooting my XCR, I am constantly checking the barrel bolt. I am at 3100 rounds since I last torqued my bolt, so my confidence is still building with it. But it's something extra that you don't need to think about with an AR.



You don't need to carry a torque wrench to tighten the barrel. I have a 6.8 caliber conversion and switch barrels more than most ever would. I haven't had the barrel loosening on me. Get the proper size Allen wrench, tighten until snug, muscle out another quarter turn and you're set. This is such an overblown issue.





Good God it is.... I just snug it good and tight, it's not like you need to gorrilla the damned thing on there!
diversmith  [Team Member]
2/9/2010 2:20:40 PM EST
Damn....what a bunch of Nancys

If you take it apart, clean the threads and put a small dab of red loctite on there and tighten according to the manual's directions. It really isn't that hard people
slanted  [Team Member]
2/9/2010 3:33:46 PM EST
No issues here either. Just saying...
ds3_09  [Member]
2/9/2010 4:20:44 PM EST
Well I can't hardly wait for mine. I got it for $1350 shipped unfired. I am the second owner though. It is the newest version.

I have a PRI flip up front sight, matech rear sight, tango down battelgrip, and troy battle rail covers. It's the perfect compliment to my STG-E4 and my LMT 10.5.

I don't think I plan to get any other .223 rifles. The ACR and SCAR are simply to much for a production rifle.
ShogunOfHarlem  [Team Member]
2/9/2010 4:22:50 PM EST
Originally Posted By ds3_09:
Well I can't hardly wait for mine. I got it for $1350 shipped unfired. I am the second owner though. It is the newest version.

I have a PRI flip up front sight, matech rear sight, tango down battelgrip, and troy battle rail covers. It's the perfect compliment to my STG-E4 and my LMT 10.5.

I don't think I plan to get any other .223 rifles. The ACR and SCAR are simply to much for a production rifle.


That's a pretty sweet deal for an unfired one. Post pics when you get it.
LoadedDrum  [Team Member]
2/9/2010 6:23:47 PM EST
Originally Posted By ds3_09:
What I had read was that having one bolt is insufficient/weak. Like say drop the gun on the end of the barrel it might not fair well. I've never handled and XCR so I am just asking.


AR barrels are attached with just one nut.
ds3_09  [Member]
2/9/2010 6:28:59 PM EST
Originally Posted By LoadedDrum:
Originally Posted By ds3_09:
What I had read was that having one bolt is insufficient/weak. Like say drop the gun on the end of the barrel it might not fair well. I've never handled and XCR so I am just asking.


AR barrels are attached with just one nut.


That's a whole different ball game. The barrel nut on an AR is a substantially different design.

I'm looking forward to my XCR. I have read of concern over the barrel attachment region and that it is the XCR's weakness. My XCR will mostly be shot from a bench on sunny afternoons. I'm really not all that concerned I just wanted to ask if it was a valid concern. I have never personally inspected an XCR or the bolt that holds the barrel in.
aimpointed  [Member]
2/9/2010 6:59:32 PM EST
Never a problem with mine, and I swapped out a 16" for a 12" barrel
HK51Fan  [Member]
2/9/2010 7:08:59 PM EST
I have a 5.56 rifle with the 7.62 conversion. i've switched them back and forth with no problems.
Martens  [Member]
2/9/2010 7:42:25 PM EST
I've had more barrels come loose on my AR than any of my XCR's (1 on the AR and 0 on the XCR's).

BR870  [Team Member]
2/10/2010 8:20:09 AM EST

Originally Posted By ShogunOfHarlem:
Originally Posted By ds3_09:
Well I can't hardly wait for mine. I got it for $1350 shipped unfired. I am the second owner though. It is the newest version.

I have a PRI flip up front sight, matech rear sight, tango down battelgrip, and troy battle rail covers. It's the perfect compliment to my STG-E4 and my LMT 10.5.

I don't think I plan to get any other .223 rifles. The ACR and SCAR are simply to much for a production rifle.


That's a pretty sweet deal for an unfired one. Post pics when you get it.

He bought it from me. I got it a few months ago, and just never got around to firing it. Originally I had put it up for sale to fund an ACR, but we all know what happened there. Afterwards I sorta shifted focus over to an AUG A3.

Even though I never fired it, it seemed solidly built.
XCRmonger  [Team Member]
2/10/2010 1:21:21 PM EST
Originally Posted By ShogunOfHarlem:
My SHTF fantasies don't involve me lugging around a torque wrench.

With AR FSB pins, you tap em in and forget about them. When shooting my XCR, I am constantly checking the barrel bolt. I am at 3100 rounds since I last torqued my bolt, so my confidence is still building with it. But it's something extra that you don't need to think about with an AR.


a torque wrench, while nice, is not really necessary. You can hand tighten + an additional quarter turn and it's the same.
JohnnyMcEldoo  [Member]
2/10/2010 1:22:36 PM EST
The male threads on the upper receiver on an AR that the barrel nut screws on to is a significantly weaker mounting design than the XCR in terms of mass and support.

The XCR is by no means the be all end all but its pretty damn good for the price.
ds3_09  [Member]
2/10/2010 1:58:28 PM EST
Well I hope it doesn't seem like I was trying to bad mouth XCR's. I will post pics eventually.
LoadedDrum  [Team Member]
2/10/2010 3:47:19 PM EST
Originally Posted By ds3_09:
Originally Posted By LoadedDrum:
Originally Posted By ds3_09:
What I had read was that having one bolt is insufficient/weak. Like say drop the gun on the end of the barrel it might not fair well. I've never handled and XCR so I am just asking.


AR barrels are attached with just one nut.


That's a whole different ball game. The barrel nut on an AR is a substantially different design.

I'm looking forward to my XCR. I have read of concern over the barrel attachment region and that it is the XCR's weakness. My XCR will mostly be shot from a bench on sunny afternoons. I'm really not all that concerned I just wanted to ask if it was a valid concern. I have never personally inspected an XCR or the bolt that holds the barrel in.


I should have left the out. Sorry, I was just in a snippy mood, no disrespect intended.

The barrel attachment is certainly not weak, and I just cannot stand the people who think the SCAR barrel attachment method is better because of its six bolts. If the barrel attachment wasn't also the rail that a grenade launcher was mounted to they would not need so many. LMT uses two smaller bolts on the MRP. RA uses one larger bolt on the XCR. The same function is achieved sucessfully in both cases.
SeanK1ng  [Member]
2/12/2010 5:49:09 PM EST
Originally Posted By ShogunOfHarlem:
Originally Posted By CarlAMG1:
Originally Posted By ShogunOfHarlem:
My SHTF fantasies don't involve me lugging around a torque wrench.

With AR FSB pins, you tap em in and forget about them. When shooting my XCR, I am constantly checking the barrel bolt. I am at 3100 rounds since I last torqued my bolt, so my confidence is still building with it. But it's something extra that you don't need to think about with an AR.



You don't need to carry a torque wrench to tighten the barrel. I have a 6.8 caliber conversion and switch barrels more than most ever would. I haven't had the barrel loosening on me. Get the proper size Allen wrench, tighten until snug, muscle out another quarter turn and you're set. This is such an overblown issue.





I've used the method to tighten the barrel bolt without a torque wrench, just using a regular allen wrench on my first XCR. The barrel bolt would back out after a couple hundred rounds consistently.


Then you simply weren't tightening it enough to 'stretch' the bolt and achieve the proper clamping force. This isn't rocket science guys.....if you torque it to 20 ft. lbs or 240 in-lbs....you should never have a problem. If you want to simply crank the shit out it with a standard allen.....seems to work fine for me.


JME,
Sean
LoadedDrum  [Team Member]
2/13/2010 6:36:36 AM EST
Originally Posted By SeanK1ng:
Originally Posted By ShogunOfHarlem:
Originally Posted By CarlAMG1:
Originally Posted By ShogunOfHarlem:
My SHTF fantasies don't involve me lugging around a torque wrench.

With AR FSB pins, you tap em in and forget about them. When shooting my XCR, I am constantly checking the barrel bolt. I am at 3100 rounds since I last torqued my bolt, so my confidence is still building with it. But it's something extra that you don't need to think about with an AR.



You don't need to carry a torque wrench to tighten the barrel. I have a 6.8 caliber conversion and switch barrels more than most ever would. I haven't had the barrel loosening on me. Get the proper size Allen wrench, tighten until snug, muscle out another quarter turn and you're set. This is such an overblown issue.





I've used the method to tighten the barrel bolt without a torque wrench, just using a regular allen wrench on my first XCR. The barrel bolt would back out after a couple hundred rounds consistently.


Then you simply weren't tightening it enough to 'stretch' the bolt and achieve the proper clamping force. This isn't rocket science guys.....if you torque it to 20 ft. lbs or 240 in-lbs....you should never have a problem. If you want to simply crank the shit out it with a standard allen.....seems to work fine for me.


JME,
Sean


This.

MadDogDan  [Member]
2/13/2010 7:34:41 AM EST
ds3_09:

You keep saying "I read" this or that. Well guess what, most of what you have read about the barrel bolt attachment area comes from people who "do not own" an XCR and just don't like the design. I have had mine for about 5 years now and swap barrels quite often. I don't use a torque wrench and have never had a problem but I do use a drop or two of loctite. It is stupid not to use loctite on most bolts on "any" firearm unless it is a part that will not function or become damaged with loctite. Someone mentioned tightening the barrel bolt down to 20 ft/lbs. I just built a new AR upper using a Vltor VIS upper and Noveske Diplomat barrel in 6.8 SPC. Guess what, the manufacturer says to torque the barrel nut down to 40 ft/lbs. Any armorer knows that "every" upper or rifle manufacturer has torque specs for the barrel attachment system. Why should the XCR be any different?

That crap about dropping the barel from heights can sheer off the barrel bolt is laughable. Just like the AR15 design the XCR barrel is inserted until the extension comes to rest against the upper's shoulder. It can't move any farther at that point. The extension index hole is lined up perfectly with the barrel bolt. There is absolutely no way you can sheer that bolt by dropping the rifle on the muzzle without destroying the upper first.

I also heard an urban legend that says your XCR barrel bolt can back out and the barrel will fly down range. I decided to test that myth with my old barrel (first barrel that I later changed out for an 11") by "completely removing" the barrel bolt and trying to do a mag dump. After 4 rounds the barrel shifted far enough (about 1/8") so that the bolt would not lock completely in battery. THAT WAS IT, NO FLYING BARREL, NO KABOOM.

You people really have to stop listening to rantings on the net and do some hands on research,
MadDog
ds3_09  [Member]
2/13/2010 4:04:12 PM EST
I've just read a few negative remarks about the barrel attachment apparatus. I figured it was overblown or made up. I just wanted arfcoms general consensus. If I was overly concerned I would not have purchased one. I will take posession of mine tomorrow.
B44T  [Team Member]
2/13/2010 8:00:30 PM EST
Originally Posted By diversmith:
Damn....what a bunch of Nancys

If you take it apart, clean the threads and put a small dab of red loctite on there and tighten according to the manual's directions. It really isn't that hard people


Please NO DO NOT USE THE RED STUFF. Use the blue.
I have been lucky and seen many others get lucky with the red (permanent) LocTite because the threads were oily.
If the threads are de greased when you tighten your RED LocTite-ed fastener,,,,It just became impossible to remove with out a torch.

I speak from experience gained the hard way on this.


Edit To Add;

There are Industrial red, yellow and blue LocTites that you may have seen on some things like BUIS and butt stock screws. They are rubbery. Think of them as a kind of factory applied Nylock. They are not the same stuff as #272 red that is common at auto and hardware store.
ds3_09  [Member]
2/14/2010 12:05:06 PM EST
OK I got the rifle. It seems very nice and solidly built. I love the monolithic rail. There is a little more play between the upper and lower than the AR15's I have personally owned but it's not bad. I've handled AR's with MUCH more play.

The screw for the tango down battlegrip would not thread into the receiver. It felt like it was about to cross thread so I stopped. I just used the screw that came with the A2 grip on it. I didn't want to strip anything so I didn't mess with it for long.

The only thing that kinda worries me is I bought some troy rail covers and they are quite loose even when fully locked. I pulled out my LMT 10.5 with a Daniels Defense quad rail and slapped the rail covers on it. They are not loose at all on the LMT. I guess I may return the troy covers and try something else.

It really feels nice and looks awesome. I don't see why it isn't more popular. It has a lot going for it.

Is there a sling mount on the rear of the receiver? On page 3 it says sling attachment and points to the rear of the the receiver. I see an oval hole. Is there supposed to be a mount for this? I wouldn't want to attach a sling to a stock that folds. I would much rather it attach to the receiver.
ds3_09  [Member]
2/14/2010 12:23:13 PM EST
I may try some tango down rail covers. They have always been tighter than shit when I have had them.
bolster  [Team Member]
2/14/2010 1:08:07 PM EST
Originally Posted By ds3_09:

Is there a sling mount on the rear of the receiver? On page 3 it says sling attachment and points to the rear of the the receiver. I see an oval hole. Is there supposed to be a mount for this? I wouldn't want to attach a sling to a stock that folds. I would much rather it attach to the receiver.


If this is a newer XCR, there is a point for a QD sling swivel on the bottom of the stock adapter (rifle side of the hinge).
ds3_09  [Member]
2/14/2010 4:57:23 PM EST
It has ladder covers on it for now. I'm not really a fan of ladder covers though.

BR870  [Team Member]
2/14/2010 5:14:01 PM EST

Originally Posted By ds3_09:
It has ladder covers on it for now. I'm not really a fan of ladder covers though.
http://i551.photobucket.com/albums/ii480/DrillNFill_09/059.jpg
http://i551.photobucket.com/albums/ii480/DrillNFill_09/064.jpg

She looks different... Must be the irons and TD grip.

Hope you enjoy it.
Standard  [Member]
2/14/2010 8:02:00 PM EST
Nice pics! Mine comes in in a couple of days
SeanK1ng  [Member]
2/15/2010 6:15:35 AM EST
Originally Posted By ds3_09:
OK I got the rifle. It seems very nice and solidly built. I love the monolithic rail. There is a little more play between the upper and lower than the AR15's I have personally owned but it's not bad. I've handled AR's with MUCH more play.

The screw for the tango down battlegrip would not thread into the receiver. It felt like it was about to cross thread so I stopped. I just used the screw that came with the A2 grip on it. I didn't want to strip anything so I didn't mess with it for long.

The only thing that kinda worries me is I bought some troy rail covers and they are quite loose even when fully locked. I pulled out my LMT 10.5 with a Daniels Defense quad rail and slapped the rail covers on it. They are not loose at all on the LMT. I guess I may return the troy covers and try something else.

It really feels nice and looks awesome. I don't see why it isn't more popular. It has a lot going for it.

Is there a sling mount on the rear of the receiver? On page 3 it says sling attachment and points to the rear of the the receiver. I see an oval hole. Is there supposed to be a mount for this? I wouldn't want to attach a sling to a stock that folds. I would much rather it attach to the receiver.



This is the style of sling mount that goes in the hole on the rifle side of the hinge on the stock:

You can pay $13 each for a Troy or MI.....or KZ has 1 for about $7 at http://www.botachtactical.com/kzqdslsw.html

Hope that helps (though some will say Botach sucks.....I've ordered around 10 times with no issues....but I always check to make sure they have it in stock before ordering).

Sean


ds3_09  [Member]
2/15/2010 7:01:38 AM EST
Originally Posted By SeanK1ng:
Originally Posted By ds3_09:
OK I got the rifle. It seems very nice and solidly built. I love the monolithic rail. There is a little more play between the upper and lower than the AR15's I have personally owned but it's not bad. I've handled AR's with MUCH more play.

The screw for the tango down battlegrip would not thread into the receiver. It felt like it was about to cross thread so I stopped. I just used the screw that came with the A2 grip on it. I didn't want to strip anything so I didn't mess with it for long.

The only thing that kinda worries me is I bought some troy rail covers and they are quite loose even when fully locked. I pulled out my LMT 10.5 with a Daniels Defense quad rail and slapped the rail covers on it. They are not loose at all on the LMT. I guess I may return the troy covers and try something else.

It really feels nice and looks awesome. I don't see why it isn't more popular. It has a lot going for it.

Is there a sling mount on the rear of the receiver? On page 3 it says sling attachment and points to the rear of the the receiver. I see an oval hole. Is there supposed to be a mount for this? I wouldn't want to attach a sling to a stock that folds. I would much rather it attach to the receiver.



This is the style of sling mount that goes in the hole on the rifle side of the hinge on the stock: http://ep.yimg.com/ca/I/botach_2093_71774504

You can pay $13 each for a Troy or MI.....or KZ has 1 for about $7 at http://www.botachtactical.com/kzqdslsw.html

Hope that helps (though some will say Botach sucks.....I've ordered around 10 times with no issues....but I always check to make sure they have it in stock before ordering).

Sean




Yes I saw it after the first guy said it. Thanks . It is a nice gun.
ds3_09  [Member]
2/16/2010 2:00:13 PM EST
Ok I compared the XCR screw and the tango down screw and it is obvious they are different thread patterns. I guess I assumed the XCR had the same thread pattern since it is an A2 grip.

I shot a little over a hundred rds through it yesterday without issue. On setting 4 it was launching brass so I turned it down to 3. I didn't have a single issue. It's a solid rifle. I ordered some more accessories and a TA01 for it.
MadDogDan  [Member]
2/16/2010 7:05:53 PM EST
ds3_09: I just installed a set of Troy rail covers on a Vltor VIS monolythic railed upper and they were loose and rattled. I took them off, flipped them over so the under side of the covers were showing, and used a heat gun to soften the underside a little. When the plastic is somewhat soft you can push with your fingers and flatten the underside of the covers a little. Let them cool down and reinstall. They will be very tight and you can't tell that they have been modified or fitted to a specific rail in any way. Since they are made of hard plastic they will retain their new shape for ever.

Hope this helps for you Troy lovers,
MadDog
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