Posted: 8/3/2017 10:44:23 PM EDT
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I shoot my Costa quite a bit. I've got about 6000 rounds through it. First firearm I've ever shot this much. About a month or so back I noticed I wasnt hitting what I was aiming..more so than normal...and after posting and following some advise, gave the barrel a good deep clean with Sweets and things got back to normal. Today however I had another new experience. While cleaning up after running 10 mags, I noticed the Cerakote on the edge of the defector was worn down to bare aluminum. I was moving while I was shooting, so no pile of brass. After a bit of research, it looks like the consensus is that I'm under gassed. I don't run a suppressor and port selector is set accordingly. I guess like anything after use things start happening, even to a Costa.....I run only good factory ammo...today it was Hornady 62gr TAP.
Last time my solution came from here. I asked a while back for a Grendel barrel for my Costa and it looks like my request was heard in the form of an upper kit.... but I'm not done with my 5.56. Is it time to tear down the gas block, re-seat it, and maybe replace the gas tube?...or should I start somewhere else? |
| I wonder if during all that cleaning that stripped the copper, if it didn't loosen up some gunk that again hardened inside the PST? I know SLR provides a side plate on their gas blocks so that it can be removed for cleaning. There must be a need for regular maintenance. Last time I tore down my OBR upper for a thorough cleaning I left the PST alone. I think LaRue recommends not removing it. So, you may have to get creative on how to clean it. Maybe spray some solution down the gas tube and use compressed air after it's taken effect? |
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Gas rings?
Ejector spring pressure? Extractor claw and spring pressure? Gas tube tip in the upper? Run some solvent through the gas tube and let it run down through the gas block, gas hole, and out the muzzle onto a paper towel or white paper. Look for debris/copper/etc. I doubt it's clogged. |
| So, the rifle is running fine, but you had wear on the deflector? It was ejecting at 3-4 o'clock and now it's not? 6,000rds is a pretty good run for some parts. Have you ever stripped the bolt and cleaned it? Can you check the extractor and ejector? I'm not leaning towards the spring as I believe Sprinco's are rated to something like 1,000,000 cycles. |
| I tear it down each time I shoot. It got copper fouled from I guess not using good copper solvent, not from not cleaning. Nothing is visible that would indicate a problem other than the wear on the deflectorthat happened very quickly. I'll get some pics up in a bit. It my favorite rifle but maybe it's a sign to retire the 556 in favor of the Grendel kit that is coming.......just kidding...kinda.... |
the gas rings could be worn
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Quoted:
Passed the gas ring test above. Here is a pic.....am I being too anal, as everything seemed to be checking out....except for the strikes...which in hi res blown up, really don't look like many...? https://www.AR15.Com/media/mediaFiles/332320/IMG_0993_JPG-274939.jpg |
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I'm at the 9,200(ish) mark on this Costa.
Attached File Attached File Attached File |
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I don't think, but unsure.
It's the factory bolt that came with rifle.Attached File Here it is cleaned up. 90% of my round count has been wolf gold if that matters. I've not lost any accuracy with it. Have not babied it...actually chucked it at the target during last class 
LT stuff is tough as nails. |
| I did shoot new ammo for the first time, which might be the issue, but I didn't introduce any other factors that I can imagine that haven't been experienced in the past few years. I've never put this many rounds through a rifle and I never had experienced the issue before. I did have some copper fouling that I only discovered when my groups started opening up, so seeing the strikes that were non existent before made me wonder.......but I'm not going to be concerned anymore as long as it keeps cycling. |