Robinson XCR, 1-9 Twist, and 75-77 grain 5.56 rounds


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HorseSoldier
November 6, 2008, 04:17 PM
Thinking about adding an XCR to the collection, and was wondering if some owners and/or those familiar with the design could provide some information on how the XCR runs with heavier 5.56 bullets.

From what I see on Robinson's website, the XCR in 5.56 is only offered with a 1-9 twist rate. My two existing 5.56 rifles are both 1-7 twist, and I prefer running 77 grain ammo through those. Having to stock two different bullet weights in 5.56mm would be almost as much trouble as stocking two seperate calibers, so I'm thinking the potential purchase probably hinges on how well the XCR/1-9 twist combo does with 75-77 grain rounds.

I'm not necessarily looking for a quarter-MOA bench rest or uber-mallninja performance, but just wanted to verify the XCR delivers service rifle/patrol carbine acceptable sort of accuracy with heavier bullets.

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Slvr Surfr
November 6, 2008, 04:49 PM
I own one but I can't give you an answer as all of run through mine is 55gr ammo. Here is where I can point you to hopefully get your answers:

http://xcrforum.com/

everallm
November 6, 2008, 04:54 PM
Horsesoldier,

If I recall correctly, Robinson Arms did say that they tested 75gr in 1:8 and 1:9 barrels and saw minimal difference.

Mine is good to go with 75gr A-Max's but I have one of the first run 1:8 heavy barrel XCR's so don't want to prejudice the answer for the current barrek

Go to www.xcrforum.com and post the question there, owners will be able to give you real world experience

HorseSoldier
November 6, 2008, 05:03 PM
Thanks for pointing out the link. They've actually got a thread about the exact question I had and the 2-3 XCR shooters who've tried 77 SMKs and other heavy bullets report good results out to 100, and then some looser groups than an AR shooters past that. Nobody talking about keyholing, though, which was my main concern (having seen some M16A1s loaded with green-tip on a range once . . .).

ny32182
November 6, 2008, 05:12 PM
I could try 77's in mine, but have not so far... the reports I have seen from those that have state that the accuracy is not bad, but not as good as in a 1:7 barrel. That is pretty standard, and I doubt those results are going to change just because the barrel is sitting in an XCR reciever rather than in an AR.

Since I already have some 1:7 AR's, I don't mind that the XCR is a 1:9 for varieties sake... historically I have found that the 1:9's tend to shoot the lighter-than-77 stuff a little better for me anyway.

I have not done a lot of accuracy testing in my XCR, but plan to do so soon. I have loaded up some 69gr SMKs and 60gr VMAXs.

zx12rider
November 6, 2008, 05:16 PM
How do you guys like your XCR's? I was thinking about ordering a CT compliant one with fixed stock and perm brake. 16" barrel

Dr. Tad Hussein Winslow
November 6, 2008, 05:19 PM
Horsesoldier, could you please post a direct link to the thread in question you found addressing your exact question (on XCR forum)? Thanks.

zx12rider, so far, so good - love it. But haven't shot it much yet.

ny32182
November 6, 2008, 05:32 PM
Mine is all good so far:

http://img.photobucket.com/albums/v212/ny32182/DSC02707.jpg

Magpul covers and MIAD grip, Bobro short grip, Troy BUIS, TA11F w/LT100. Since that pic I have gone to the large MIAD backstrap which I have always preferred, and added a "gapper"... she's just about perfect in 5.56 config. I would like to get either the 6.8 or 6.5 parts for it sometime in the future as well.

These are some groups with ordinary Hornady 55gr FMJ and ~23gr H335:

http://img.photobucket.com/albums/v212/ny32182/DSC02717.jpg

Slvr Surfr
November 6, 2008, 06:04 PM
Love the rifel, hate the trigger. It has one of the worst out of box triggers I have ever felt. Sometimes its a one stage and others times a two stage. The rifle itself is well engineered, and rock solid. The trigger solution is cheap. I can send it off and it will come back with a smooth single stage trigger. Other than that I haven't gone to any carbine classes with it yet. I've only had around 300 rounds through mine, and not a single hiccup.

ny32182
November 6, 2008, 06:16 PM
I had the Springfield 4.5lb single stage job done on mine... well worth the $49.

There is also a factory match trigger in the pipeline from RA.

HorseSoldier
November 6, 2008, 06:32 PM
Horsesoldier, could you please post a direct link to the thread in question you found addressing your exact question (on XCR forum)? Thanks.

It's in the 5.56mm subsection: http://xcrforum.com/index.php/topic,1024.0.html

everallm
November 6, 2008, 06:44 PM
@ZX12rider,

Rob Arms posted today on XCR forum that they are crazy busy and have a bit of a backlog on rifles and components...... No real surprises there.

If you are really interested probably the best go to guy to order from who carries stock is Kermit Zahm

Kermit Zahm
Wild Thang Farms
3150 Fuller Rd
Emmett , Idaho 83617
frgprnz@outdrs.net
phone 208-869-1616
Fax # 208-365-4272
FFL 9-82-045-01-7D-35203

I live in NJ and have to get the same model as you guys in CT and he was excellent.

Slvr Surfr
November 6, 2008, 07:55 PM
I had the Springfield 4.5lb single stage job done on mine... well worth the $49.

That is what I was referring to as a cheap fix. I have read nothing but good things about his trigger job.

tacweapon
November 6, 2008, 08:11 PM
This is my Robinson Arms XCR

http://i296.photobucket.com/albums/mm196/tacweapon/XCR/100_1084.jpg

I do not mind the trigger but that said I do plan on seeing what there match trigger is like or getting a Bill Springfield trigger job

Here is what I was able to get using a 16 inch heavy barrel and 55gr Black Hills Ammo

http://i296.photobucket.com/albums/mm196/tacweapon/Targets/100_1102.jpg

That was taking a shot as soon as I had my target picture back on a 2x TruGlo optic so the shots were fairly rapid, if I had taken my time and or had a better optic I know I would have done better

I would imagine you would have about the same groupings with the heavier bullets, I have shot up to 68gr and the groups were about the same as what I get with the 55gr and 62gr

I hope this helps

Dr. Tad Hussein Winslow
November 7, 2008, 09:46 AM
tacweapon, nice group - that is a deadly weapon in your hands right there! That's good shootin for a 4 power scope (millet dms) at 100.

If you enjoyed reading about "Robinson XCR, 1-9 Twist, and 75-77 grain 5.56 rounds" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!