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Robinson XCR barrel length change?

Discussion in 'Rifle Country' started by Dr. Tad Hussein Winslow, Oct 17, 2008.

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  1. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    XCRs *were* 18.6" or thereabouts. Finally got my XCR yesterday and lo and behold, it's 16" (5.56mm) (didn't measure when buying). Not sure if I'm happy or disappointed. A little disappointed; I had wanted the 18.5". This change just happened in the last 2 or 3 months, apparently. It's definitely light and handy, but I had thought the 18.5 to be a perfect compromise between 16 and 20. Hmmmm. Anyone with an 18.5 want to trade for this 16"? - ha!

    Well, good news is, barrels are quick-change, so I could get another bbl if I want....

    Pics to follow - and yes, I'm very very pleased here about the situation in general - this is my Obama rifle. :)
     
  2. Marcus L.

    Marcus L. Member

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    That's news to me. I bought my XCR in early 2006 and it came with the standard 16" light barrel with a 1 in 9 twist. The 16" barrel has always been the standard. I've never heard of the XCR being offered in anything other than 16" unless you specifically order one with a longer option. If you did order one from Robinson Arms in 18.5", then email them your receit and they should fix the error. If you made the order through a gun dealer, you might have a headache getting them to correct their error as they might tell you something like "we couldn't get one with that option".

    As far as the 16" barrel goes, I'd only be concerned with it if you plan on shooting targets beyond 150 meters with military FMJ ammo. Use a good OTM or JSP load and you can expect good fragmentation/expansion up to 300" yards with a 16" barrel. M193 and M855 are not very dependable combat loads in comparison to cheap JSP, OTM, or hollow points. Even Wolf JSP ammo out of a 16" barrel would probably be a better choice than M193/M855 out of a 20" barrel if you are concerned about terminal effects. Here's a little read on the problems with using M193 and M855 which often do not fragment reliably even from a 20" barrel:

    http://www.dtic.mil/ndia/2008Intl/Roberts.pdf

    Top of the line loads are the Hornday 75gr OTM which is ideal for home defense or outdoor work. Federal Tactical Bonded 62gr JSP is the best overall combat load(very expensive though) as it shoots through barriers with ease and expands nicely. If you are concerned about accuracy, stick a Vortex Flashhider on your XCR and you'll see your groups improve.
     
  3. tacweapon

    tacweapon Member

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    Mine is the standard 16" but I know that the 18.6 is offered If you ordered it directly from Robinson Arms I am sure they would fix it for you and I would bet that even if you ordered it from a dealer they would take care of you

    Contact Terra Shrewsburry ( Robinson Arms Customer Service Representative )
    at
    terra.robarm@gmail.com

    She has taken care of me and a lot of other people with XCR and the M96 and the VEPR

    Also go to http://xcrforum.com/
    Its a forum for the XCR and Robinson Arms
     
  4. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    Oh, ok, I had misunderstood - I thought the standard was the 18.6" - but now I see that they have both. Cool. The 16" actually may be more accurate - thanks for all the ammo advice and RobArm customer service information; very helpful! :)
     
  5. Marcus L.

    Marcus L. Member

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    You chose very wisely for your "Obama Rifle". The XCR is one heck of a well designed rifle and it's a shame that I can't have one in full auto. It's just one of those weapons you never want to sell.....bury it in the backyard if the gun grabbers come knocking. I've shot a lot of the competition like the Sig 556, FN SCAR, and handled the MagPul Masada and I still consider the XCR to be the best overall design. Sure it doesn't have the mall ninja plastic stock with cup holder, but I can add one later if I should want to. What's important is how well it allows you to rapidly put accurate shots on target, doesn't malfuction on you in bad environments, and is intuitive to operate. I gave mine a 1000rd training day in the dusty 110 degree Arizona heat and it kept going like the Engergizer Bunny. I kept the bolt assembly greased for long firing sessions, but I think it would have done fine with only oil.

    I think you will be plenty happy with the 16" barrel as you can get in and out of tight places easier. In most countries where barrel lengths are not a legal issue, the 16" is the middle ground barrel length and the most versitile. Some loads are more accurate than others, however I do recommend you get rid of the birdcage flashhider that comes on it and get yourself a Smith Enterprises Vortex flashhider. No visible flash at night, and it improves accuracy. The only downside is that if you are shooting prone, it will churn up a little dust.
     
  6. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    Here's a pic....put on an ERGO brand grip and a Sightron S2, 1.5-6x42mm with Warne Maxima QD rings. It'll have to do until I can afford an ACOG.

    Gonna shoot this gun tomorrow morning.
     

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  7. Marcus L.

    Marcus L. Member

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    I like the ERGO grip on mine as well:
    [​IMG][​IMG]

    Tactical sling with rail mount, Yankee Hill A2 adjusting sights, Trijicon night sights, Vortex Flashhider, the ERGO grip. That's all I need for a combat carbine. I might put my flip-up sights back on there and add an Aimpoint T-1 sight, but I haven't decided on that just yet.
     
  8. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    Marcus that looks real nice! :) Questions: Where do you get the vortex flash hider and what make/model of sling and where to buy the sling? Thanks!

    I'm thinking of putting fold down sights on there as a backup to the scope, where I could just remove scope.

    Also, which rail covers do you have? How much and where to order?

    Also how does yours shoot from a cold barrel (2 MOA?), and as a matter of physics, how can a flash hider improve accuracy? :confused:

    Also, how's your trigger? Mine is so-so, on the bad side (it's no 556), but certainly not as bad as most AR15s.

    P.S. I came *this close* to getting the model with that same folding stock as you have there, but at the last minute changed my mind and got the model you see above for $30 more, which has the VLTOR folding *and* adjustable stock (with the "sidesaddle" battery compartments). It's pretty bulky when it folds being the downside, but the upsides are: adjustable, and more comfortable cheek weld. Is there a way to open up this VLTOR stock and put stuff inside, since there's no spring in an XCR? I don't see one.

    Also, should I switch out this scope for a cheap Millett DMS-1, or save up for an ACOG, do you think, or leave the Sightron on there as is? Wanting an all-purpose rifle (fun range gun, SHTF, and some hunting/varminting). I believe I'll stick with the 16" bbl for now, instead of trying to get RobArm to swap me for an 18.6, and maybe someday order a 20" semi-heavy bbl. Note: There were TWO models available at this gun shop with 16" bbls - one heavy and one light - this is the light one I got.

    Also, what kind of grease to use? Is there any cheap Walmart type grease that will work adequately for a marathon torture session such as you describe, Marcus?
     
  9. Marcus L.

    Marcus L. Member

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    The Vortex is made by Smith Enterprise:

    http://www.smithenterprise.com/
    http://www.smithenterprise.com/products06.html

    It looks like you have the light barrel on your XCR, so you want the G6A2 model (part #1001V) for 5.56. I think I remember ordering mine from Rainier Arms:

    http://www.rainierarms.com/?page=shop/manufacturer&manufacturer=22

    There are two theories as to how it improves accuracy. One, its fibrating forks stablize gas expansion when the bullet leaves the barrel making the explosion more consistant. The other theory is that since you don't have to torque it down very tight, it allows for more consistant vibrations in the last inch of barrel. Since the forks are helical against the thread attachment direction, the gases from shooting cause the the flashhider to put twisting force against the threads to keep it tighened as you shoot. All I know is, it definately works. I've put them on three different rifles and did my own testing and in each case accuracy improved.

    Most good M4s shoot about 2 MOA, and I would say my XCR does that. I'm not a precision shooter, but my groupings are tighter at the qualification range with the XCR.

    The trigger is a two stage trigger which means you have the initial pull and it stops, then a second pull which finishes the stroke. It's a good combat trigger design because when you are under stress, the second stroke is activated from a position of tension. So, the activation is more predictable and less jerked for long shots. With a single stage trigger your finger goes from relaxed to activation, which can result in more jerk under stress. A two stage trigger kinda compensates for the "oh s**t" factor so that your shots to suffer as much. RA does make a single stage trigger if you want one though.

    My sling is a pretty high end one. It's a modular setup from Blue Force Gear:

    http://www.blueforcegear.com

    I honestly don't remember which model mine is. You can get a H&K clip to attach to the rear ring on the receiver, but I've found that it sometimes gets in the way of the charging handle. So, I just attached one end to the MI rail sling mount, and the other end I fixed to the stock by slipping it between the butt pad and the stock. Works great. Any modular tactical sling for the M4 should work for you, but you'll want to order a rail mount slight attachement. I got mine from Midwest Industries:

    http://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_id=80

    You can also get rail covers from them. Mine are ERGOs that came from RA when I bought the XCR.

    I can't give you a whole lot of advice on scopes. I don't use them that often except for hunting rigs on bolt guns. I tend to tailor my assault type rifles for quick target aquisition at close and medium ranges. The ACOG is a damn fine scope from what I've read and it might be worth it. If it were my choice, I would get a Aimpoint red dot sight for better shooting at ranges under 100m.

    As for lube, a good general purpose lube is Militec-1 for rubbing surfaces of firearms. However, you want grease which is more long term for rotating bolts and the heat buildup you get in an assault rifle receiver. I use TW-25B grease for areas like that.

    http://www.milcomm.com/weapons_lubricants.html

    I'm sure Walmart has some similar products, but I haven't looked lately. You want gun oil for light areas of friction, and gun grease for internal parts that go through a lot of wear. You want to be careful though, as oil and especially grease attract dust. In dusty environments I suppliment oil for a dry-on lube like Tuf-Glide which does not attract dust.......however, it doesn't take the place of grease. Anywhere where you notice parts rubbing, you want oil or grease on there. Since the bolt rotates inside the bolt assembly and rubs all the way around, you want grease on those areas.
     
    Last edited: Oct 18, 2008
  10. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    Thanks very very much! I've got a *small* supply of militec-1 which will get me through tomorrow. I may buy some rail covers today. Awesome advice; thanks!
     
  11. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    Update - only had time for 60 rounds - shot real nicely; no jams; didn't have time to test accuracy, but it appears to have just so-so accuracy at first blush (with milsurp ammo); more later.

    I'm amazed at the simplicity of the bolt, bolt carrier, and op rod assemblies - how they just simply plug into each other like a puzzle, with no screws to take out or anything, for a pretty detailed field strip. This gun is purt' near the ultimate in ease of cleaning!
     
  12. Marcus L.

    Marcus L. Member

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    Ammo quality really effects accuracy. Plus, accuracy improves after breakin. My light barrel is very accurate with premium ammo like Hornady TAP and Blackhills OTM. If you are going for match grade accuracy with cheaper ammo you can always buy a heavy barrel for it.

    Who says you need to clean it? :D Naw, it's good to keep it clean until you've put 300-500 rounds through it to break it in good. Keep it well lubed during the break in process as well so that parts can get worn properly. With an Obama administration, this might be the last assault rifle you'll ever own so take care of it.
     
  13. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    Thanks again, Marcus.

    Also, here are some more pics with sling and some green rail covers added:

    [​IMG]

    [​IMG]
     
  14. Marcus L.

    Marcus L. Member

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    Looks good! :D I am debating if I want to get a 6.8 SPC conversion for it while I still can.......but I've got other guns to purchase before I do that. ;)
     
  15. ny32182

    ny32182 Member

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    PS, looking good!

    My advice would just be to follow the factory directions for break in, and you should be in good shape.

    Also, it probably wouldn't hurt to make sure the barrel bolt is tight from the factory, and keep an eye on the ejector bolts; though I would not disturb those unless they come lose. Adjust the stock as you like, and off you go.

    The ACOG is a fine option; I have a TA11F on mine:

    [​IMG]

    So far, other than factory ammo I have only shot 55gr Hornady FMJ through it. Best looking load so far was a 12 round group w/ 22.6gr H335, at 2.158" max spread; 1.647 deducting one flyer.

    I am hoping to get a chance to shoot some better bullets in it this weekend. I have some 69gr SMKs and 60gr Vmax ready to load up.
     
  16. ny32182

    ny32182 Member

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    Also, I had my trigger done by Bill Springfield. He converted it to a single stage with a clean consistent break at ~4.5lb. I like it better than factory; YMMV. It is about as light as I would want it on a rifle of this type. Robarm is working on a factory "match trigger" as well, and I will probably get that as well just to see what its all about. Last I heard they were hoping to release the trigger by Christmas, I think.
     
  17. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    Thanks again guys - what setting # do you keep your adjustable gas system screw set on? I think it's on 4 from the factory/store.

    Next range trip I'm trying Black Hills 68 gr JHPs.

    I too am debating whether to get a another bbl - either a heavy 20" 5.56 or a mid-weight 18.6" in 6.5 grendel....... If a gun ban is forthcoming from BHO, then that will obviously make the company suffer and everything could dry up - they ain't gonna keep makin barrels if they can't sell the rifles, now are they?

    In hindsight, I should have gotten the shorter rail covers...

    Nice rig, ny32182! :D
     
  18. ny32182

    ny32182 Member

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    You want to run the first 300 rounds on #4, then scale it back some. If you have the newer gas system, most people will find that it runs reliably on #2 with most ammo.
     
  19. Marcus L.

    Marcus L. Member

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    What setting you use varies with the climate and how powerful the ammo is. The lower your gas setting the less pounding it puts on the parts. I've found that #3 fires just about anything I can put through it, but sometimes cheap Wolf ammo needs #4. With more powerful stuff like M193 or M855 I can get away with using #1 or #2 depending on the climate. A good indicator as to what setting you should use for your ammo is how far brass is spit out. You want it to eject to about 6-8ft. If it's just barely spitting out, you need a higher number gas setting to ensure reliable function.
     
  20. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    So #2 allows MORE gas in, for a dirtier rifle / more thrust, than #4? That's a bit counter-intuitive....

    Oh wait nevermind, it's just the opposite - Marcus, you posted and answered my question while I was posting. :)

    Then why run on #4 for the first 300 rounds? Isn't that a bit much for a clean rifle?

    So is it true that if you set the gas setting on a level that has *just* enough to cycle you, that the actual felt recoil is less?

    P.S. At the range, these two ol boys (actually young guys in their 20s) who showed up with 2 AKs, 1 AR, and 1 Sig 556, were really interested in checking out the XCR - I got the feelin that they were wishing they had spent their Sig 556 money on the XCR instead. I know I am - I was tempted by the 556.
     
  21. Marcus L.

    Marcus L. Member

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    There is going to be more friction with all the moving parts of the rifle until it is broken in. So, if you run it with more gas bleeding in to function the action(#4), then it will ensure that it runs well and the parts are smoothed out nicely.

    It is true though, you feel less recoil the lower the gas number setting that you use. However, you want to ensure that your XCR ejects with enough authority to call it reliable under dirty circumstances.
     
  22. tacweapon

    tacweapon Member

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    I have had about 4500-6000 rounds of 5.56 through my XCR and I can run Silver Bear or Wolf on setting 2 with out any problem and I could probably go down to setting 1 but I have not tried it

    Heres Mine

    [​IMG]

    [​IMG]

    I have the heavy barrel but I plan on switching it out for a light barrel
    I have also got rid of the Millet DMS-1 that was on it in that picture since I could not get a good sight picture with my weak eye

    I would follow Robinson Arms instructions for break-in and not skip any steps and then go down to the lowest gas setting you can and still have your spent casings eject about 6-8 feet
     
  23. Dr. Tad Hussein Winslow

    Dr. Tad Hussein Winslow member

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    I'll check on that, but the manual says to make sure that you do not overtighten it or it could ruin the receiver.

    Wow, very nice tacweapon! Thanks for all the advice!



    I assume that the XCR is like most rifles in that you don't want to get oil/grease into the firing pin channel, right? What all should I lube besides the whole rod/bolt/carrier assemblies, and the trigger?

    Very nice. I'm interested in a trigger job such as you had done by Mr. Springfield.

    Very next thing though is going to be that Vortex flash hider.
     
  24. Marcus L.

    Marcus L. Member

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    Getting oil in the firing pin channel is a problem because if you get dust in there your firing pin may not work. Oil attracts dust and dust creates a great deal of friction and your firing pin may not detonate primers. It doesn't seem to be a problem with getting oil on the primers. I've seen several tests where cartridges were soaked with oil or WD-40 for about a week and they all fired with no problems. Keep your firing pin channel dry, or use a special dry lube like Sentry Solutions Tuf-Glide like I do.
     
  25. ny32182

    ny32182 Member

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    Hmm... well, while I'm sure anything can possibly be overtorqued, with the barrel bolt you definitely want to err on the side of tightness. I believe the spec is 250 in/lbs. Unfortunately I have not acquired a good torque wrench yet.. in the mean time, I use an "L" shaped wrench with the long side being about 6" I guess. I torque my barrel bolt about as hard as I can by hand witht that wrench.
     
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