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Discussion Starter · #1 ·
What experiences have 6.8 shooters had in terms of particular ammunition and gas settings to run reliably on your XCR? How was your break in period?

I am about 400 SSA rounds into my 6.8 kit and it hasn't been the smooth break in I experienced with the 5.56. FTE's and stove pipes mainly with some light primer strikes mixed in as well. The ejection issues are gas related I'm sure and I can't go below 4 without it regularly getting hung up one way or the other. On setting four it isn't as often but has the same symptoms. I've inspected the gas valve by removing it and making sure all the passages are clear, lubed the bolt and carrier up nicely, C products and PRI mags, etc. I converted back to 5.56 again to see if my problems are limited to my 6.8 kit.

I certainly hope to have it running right soon and using the lower gas settings.
 

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I take it that everything was fine when you changes back to 5.56? To be honest I didn't have a break in period with 6.8. I figured that the gun was already broken in with 5.56 so I shot a mag or so on setting 4 then tuned it down to 3 as it was spitting them way to far on 4. I think with my SBR I shoot on 2 most of the time then turn it up to 3 when it starts to get really hot. I would say to check the gas block seating on the barrel and make sure that it is lined up properly. Other than that I can't think of anything off the top of my head.
 

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Discussion Starter · #3 ·
I haven't been to the range yet with 5.56 but am trying to go this afternoon. I have removed the gas block as well, checked the gas port in the barrel and made sure everything was fully seated after my last outing. It seems that everything with the gas block was fine when I've had the problems.

If I see similar problems in 5.56 I can forget about it being a gas block problem and look elsewhere. I can't imagine a piston would be bad but this seems gas related. I have also noticed very inconsistent ejection of the brass as well; some brass barely kicks out from the gun at all. The ejector is tight and in good condition.
 

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Just make sure you convert everything back to 5.56 before you shoot. The first time I went back from 6.8 to 5.56 I forgot the bolt. It fired fine but wouldn't eject for nothing. I figured it out my absent-mindedness after a few shots. I converted it at home a few days before going to the range to show a buddy and completely forgot about the bolt at that time.

Let us know what it does when you go to the range.
 

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Discussion Starter · #5 ·
Just make sure you convert everything back to 5.56 before you shoot. The first time I went back from 6.8 to 5.56 I forgot the bolt. It fired fine but wouldn't eject for nothing. I figured it out my absent-mindedness after a few shots. I converted it at home a few days before going to the range to show a buddy and completely forgot about the bolt at that time.

Let us know what it does when you go to the range.
Yes, I saw your earlier post about mixing things up so I am pretty careful when converting. I'll report back. I really like the 6.8 SPC controlled by the PWS FSC30 brake so I'm anxious to get the 6.8 running right. It really is a sweet soft shooter when it's managed to shoot on 2 & 3 and there is no question about the additional punch over 5.56.
 

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To answer your question, I'm 100 rounds in on my spanking new 6.8.  I was shooting the Rem. 115 gr OTM stuff.  I only had a light primer strike on the first round.  That was the only problem I had.  I'll stay on setting 4 for a few hundred more rounds and keep you posted on the results when I go to 3. I've got some SSA rounds to try out on my next trip to the range and will see if there are any noticeable differences.  I'm using PRI and Pro mags.
 

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The more I think about it it sounds like what my 11" 5.56 barrel does with my reloads. I never drilled out the gas port o my 5.56 when I cut it down. Until I do I have to shoot on setting 4 or else I get lots of FTE's and stovepipes (only when shooting my plinking reloads). When I shoot a little higher pressure ammo it does just fine and can even go down to setting 3. If I shoot a mag of factory stuff through it it does fne with my reloads on 4. Almost like it needs to get warmed up or something. I am wondering if maybe you got some underpowered ammo? We will know for sure once you shoot 5.56 and see how it runs.
 

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Discussion Starter · #8 ·
The more I think about it it sounds like what my 11" 5.56 barrel does with my reloads. I never drilled out the gas port o my 5.56 when I cut it down. Until I do I have to shoot on setting 4 or else I get lots of FTE's and stovepipes (only when shooting my plinking reloads). When I shoot a little higher pressure ammo it does just fine and can even go down to setting 3. If I shoot a mag of factory stuff through it it does fne with my reloads on 4. Almost like it needs to get warmed up or something. I am wondering if maybe you got some underpowered ammo? We will know for sure once you shoot 5.56 and see how it runs.
Well I ran without a hiccup on 150 rounds of Fiocchi 223 Remington. Went down from 4 to quickly running on 2 with no problems. No light primer strikes, ran like a champ.

I switched back to 6.8 and really lubed the bolt, carrier, ejector, upper, etc. I already loosened the gas block, checked all the ports and repositioned the gas block since I last shot 6.8 as well. I'm going to bring the gas dial button from my 5.56 block and switch that out if problems continue. I'm not sure beyond that what more I can do. I'll give it another outing before I cry Uncle RA.

I have been shooting SSA 110 gr. Pro Hunters and SSA 90 gr. Varmint loads in 6.8. They are commercial loads but don't feel at all underpowered.
 

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If you feel like it you could always switch the entire Gas block from one barrel to the other just having to remove the muzzle device.
 

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Are you talking about the plastic deflector? I leave my 6.8 one on all the time now, puts the 5.56 brass right at 3 oclock and 6.8 goes to 2 oclock.
 

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Discussion Starter · #14 ·
Sounds like you have an out-of-spec gas block, my dear. You should send your barrel in to me.
Terra - I am going to give it one more try as soon as I can get to the range and then I'll be in touch if the problems continue.

BTW - Weird thing is I can put the gas dial button from my 5.56 barrel in either of my gas blocks but the one that works in my 6.8 gas block will not lock into and release the detent in my 5.56 gas block. It will slide in but it will not allow the dial to be turned to select a setting.

Happy Holidays!!

Carl
 

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I think I just learned something new. I figured that for production costs all of the gas blocks would be the same. I figured that you guys would just drill the gas port in the barrel to the correct size for that caliber to work with the gas block. I wasn't aware that the gas blocks themselves were caliber specific. This is good to know.
 

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not the blocks... just the adjust dials. The port holes are bigger for the 6.8, and the 7.62 as well. None of the caliber dials are interchangeable.
 

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Discussion Starter · #18 ·
The dial settings are different.... I hope you're not using a 5.56 dial in your 6.8 block!
No I haven't. The thought crossed my mind a something to try to fix my problem because I wasn't aware they were different but I kept the dials in the proper barrel/gas block.
 

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not the blocks... just the adjust dials. The port holes are bigger for the 6.8, and the 7.62 as well. None of the caliber dials are interchangeable.
So all the gas blocks are the same, just the dials are different.

Weird thing is I can put the gas dial button from my 5.56 barrel in either of my gas blocks but the one that works in my 6.8 gas block will not lock into and release the detent in my 5.56 gas block. It will slide in but it will not allow the dial to be turned to select a setting.
What is the difference on the dials? If all the gas blocks are the same then i would think they all would take all the dials. What is in place that makes the 5.56 block not take a 6.8 dial? If I was home I wouldn't be asking this silly question. ;)
 

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Discussion Starter · #20 ·
Sounds like you have an out-of-spec gas block, my dear. You should send your barrel in to me.
Terra - I shot again and had similar problems so a package is headed your way. Should I send you my 6.8 bolt as well just in case you need to check to see if it's functioning properly?

Let me know.

Thanks,

Carl
 
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