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Posted: 8/6/2012 2:03:11 PM EDT
| First of all I am new to the sight, and hope I am posting this in the correct forum. I have made several mistakes and am will to take any and all lashings that I deserve. Problem #1 should have found this sight first before purchase. Problem #2 purchased a blackthorne piston upper. ( probally should have stayed with di's) Main problem #3 Fail to eject. Here is what I have checked. Cleaned and luded everything many times. Changed up mags and ammo 855 and 193 work bettter but stilll have problems. Has never had a steel case in it only brass. Put a HD extractor sping in. extactor is clean and sharp. Sometimes when it jams I cane get the case out by clearing weapon other times I need a cleaning rod. The exrrator pulls hard on the case and will pull some brass off when it slips off . case is just stuck that hard. Once in a while I can run a full mag no problem then reload same mag with same ammo and one round at a time cluster. Could this be a buffer problem? Buffer does not have a H on it. is a CAA 6 position stock with standard pring and buffer. If I spay some gun oil into the chamber this helps alittle. Any help would be great. If I can't get it figured out soon it is getting scrapped. thanks ahead of time. |
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I would polish the chamber with 0000 steel wool. It shouldn't be that hard to extract the spent casings. My polishing method is to grab a 9mm brush and wrap some steel wool around it. Then chuck the cleaning rod into a drill and run it for a few minutes. The inside of your chamber needs to be smooth. ETA: Let me caveat this a bit. Inspect the chamber before performing this operation, if you notice any ridges then it needs done. If its mirror smooth it doesn't, but it sounds like its not smooth. You also want to go slow when polishing, your looking for a polish your not trying to remove a bunch of metal. Move the brush back and forth to try and keep the polishing even so your not just working one area. I've only had to do this once to a rifle and it had rust in the chamber. (I bought it that way, it wasn't due to my negligence)
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I would also add an O ring, PM me your address and I can mail you one. ETA: I like the O rings - if the bolt is going to cycle I want it to rip the case out of the chamber. If the case doesn't come out I want it to grip hard enough that it takes part of the rim off.
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| I have taken a bore brush and spun it in the chamber with solvent, but have not polished the chamber. also want to add this has been a problem i have been working on for awhile there is atleast 300 rounds down the pipe. would have thought it would start to looosen it self up. Here is one other odd part I want to add to this problem. There is no marking on the barrel was told it was 5.56 when questioned and 1 to 9. I have never seen a barrel that was not stamped. Could it not be finished completly? Thanks for the offer on the o ring but I have access to o rings and will look for one tomorrow, might have a bin full and not know it. |
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Quoted:
couple possibilities you may have a ruff chamber or overgassing problem For got to respond to this. If this was a di yep i would agree to gas problem. I thought I would try a piston with some guys really liking them so much. I don't know if everything responds the same do to the piston system. If it was a di I wold also start swaping parts with one of my other rifes that run good till i found the problem. something else i found out about piston systems ( nothing fits from another rifle) Sweeet Not. |
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piston systems still use gas to drive the piston and usually have an adjustable gas block.
i had a very ruff chamber polished it out with some emery cloth on a dowel in a drill took off too much material but it works better now and the brass doesn't look like the head will separate |
| just put the upper back together. Took the advise of polishing the chamber with steel wool. Thats what i had on hand. Stilll don't like the fact there are no stampings on barrel, but will fire this again at lunch tomorrow. Checked everything over again and all looks good. extactor is so tight should pulll the rim off. If the case sticks now I try a barrel. I also will take a differant buffer with and test with. Have a mag of 855 and one of horady. see what happens. |
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What do the stuck casings look like, are there any marks on them to indicated a rough chamber or flaws where the casing might be sticking? By spinning a chamber brush in it, you may have caused grooves, so hopefully this did not occur. Have you tried any .223 ammunition, as the M855 and M193 are 5.56? Have you checked the headpace? Have you tried a heavier buffer, action spring (buffer spring), or combination of them to slow the timing cycle down?
CY6 Greg Sullivan "Sully" SLR15 Rifles TheDefensiveEdge.com (763) 712-0123 |
| well polishing the chamber didnt help, buffer and spring didnt help. fireing one round at a time and bolt locks. oring in ejector didnt help. But when I unscrewed the piston selector 1 full round to where the detent was not doing anything other than a referance point I was able to run 1 mag through clean. Turned it back and jam jam jam. Turned back to loose and finished mag with no problems. Thought maybr it was pushing the piston rearward and slightly holding the bolt open, but was not the case. Took out end of gas block and removed piston made a stainless alignment tool to make sure gasport in barrel and block are lined up. I could see it just enter the barrel with a light down at the bolt end. Thinking it is more a gasblock/piston problem. Will see tomorrow after alignment if it is better. |
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Quoted:
First of all I am new to the sight, and hope I am posting this in the correct forum. I have made several mistakes and am will to take any and all lashings that I deserve. Problem #1 should have found this sight first before purchase. Problem #2 purchased a blackthorne piston upper. ( probally should have stayed with di's) Main problem #3 Fail to eject. Here is what I have checked. Cleaned and luded everything many times. Changed up mags and ammo 855 and 193 work bettter but stilll have problems. Has never had a steel case in it only brass. Put a HD extractor sping in. extactor is clean and sharp. Sometimes when it jams I cane get the case out by clearing weapon other times I need a cleaning rod. The exrrator pulls hard on the case and will pull some brass off when it slips off . case is just stuck that hard. Once in a while I can run a full mag no problem then reload same mag with same ammo and one round at a time cluster. Could this be a buffer problem? Buffer does not have a H on it. is a CAA 6 position stock with standard pring and buffer. If I spay some gun oil into the chamber this helps alittle. Any help would be great. If I can't get it figured out soon it is getting scrapped. thanks ahead of time. If the extractor is pulling some brass off with it, you need to slow the cycle rate to accomodate for case expansion. Put a heavier buffer on it and this should correct the issue....but don't use any steel cased ammo once you change the buffer. |
| well things are looking better. Fired the first mag no problems second mag 5 rnds and cluster. All is set in correct position Still had one rnd that needed a clening rod to push out. Think it jammed 5 times on second mag. I'll try a fine tuning it a bit more, but getting tired of this. |
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Quoted:
well things are looking better. Fired the first mag no problems second mag 5 rnds and cluster. All is set in correct position Still had one rnd that needed a clening rod to push out. Think it jammed 5 times on second mag. I'll try a fine tuning it a bit more, but getting tired of this. What type of buffer are you using? |
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Quoted:
What do the stuck casings look like, are there any marks on them to indicated a rough chamber or flaws where the casing might be sticking? By spinning a chamber brush in it, you may have caused grooves, so hopefully this did not occur. Have you tried any .223 ammunition, as the M855 and M193 are 5.56? Have you checked the headpace? Have you tried a heavier buffer, action spring (buffer spring), or combination of them to slow the timing cycle down? CY6 Greg Sullivan "Sully" SLR15 Rifles TheDefensiveEdge.com (763) 712-0123 I would definitely check the headspace. I do this on every new rifle. |
| well its been a few more weeks of BS!!!!!!!!! with this upper. But after a ar cleaning party i had, some buddies and I ran across somthing very interesting. When comparing bolts even though they were di and i had a piston ( which i believe the bolts are the same just no gas rings) The extractor claw was thin and did not drop as far into the bolt face as all the other we compared to. I pulled the extractor off my stag and went to the range. peeled off 3 mags no problem. There is only a few thousanths differance but this was enough to cause a problem. I am heading out next weekend again if there is no problems then I think it is solved. |
| That is the problme with blackthorne. Something is always out of spec with each kit they send. I have built a few and have had to change parts here and there. The last big issue I had was the fact that there mag release wasn't even the correct size. I literally had to dremel it down and custom fit it. And the others have been BCG or trigger issues. I can fix them but Id rather not take the time to sit and figure it out each time. Thats why I go name brand now as well. |
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Quoted:
well polishing the chamber didnt help, buffer and spring didnt help. fireing one round at a time and bolt locks. oring in ejector didnt help. But when I unscrewed the piston selector 1 full round to where the detent was not doing anything other than a referance point I was able to run 1 mag through clean. Turned it back and jam jam jam. Turned back to loose and finished mag with no problems. Thought maybr it was pushing the piston rearward and slightly holding the bolt open, but was not the case. Took out end of gas block and removed piston made a stainless alignment tool to make sure gasport in barrel and block are lined up. I could see it just enter the barrel with a light down at the bolt end. Thinking it is more a gasblock/piston problem. Will see tomorrow after alignment if it is better. According to the web site their piston is adjustable and has three positions to select. 1 is for normal , 2 is for dirty and 3 is cut off. Is this what you have ? |
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