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Posted: 10/25/2013 6:36:56 PM EDT
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i bought a complete CMMG upper assembly with stainless bolt a few months ago and have had a lot of fun with it as it shoots awesome and accurate and NEVER an FTE or FTL
but a week ago i took it apart to clean and the firing pin spring was broke in half. i tried emailing CMMG twice but never got a response so i took it back to Scheels where i got it and they exchanged the complete kit so i was happy as i was just wanting a new spring but i took the new bolt out today for a spin and omg what a major PITA! i shot 6 mags and each one would have at least two or three FTE's and i could not believe it with how the old bolt ran so smooth! i would think it has to be something with the extractor?? but does anyone have any idea what could be causing this? in the meantime i think im going to go back to see if they still have my old bolt and trade back and order a new spring if i cant figure this one out? |
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i had both of those but didnt install them on my last bolt and like i said it ran way smooth and from shot 1 it never failed.
im going to take the bolt apart to clean and see if anything is tight or what? also, i was using the same winchester ammo i used on the other bolt. |
| Check the cut in the extractor and also check for fore and aft movement of the conversion in the receiver. TAACOM sells a pressure plug plus up graded extractors, firing pin and spring. Until 22 rimfire ammo disappeared on store shelves I used fire a couple thousand rounds a month. An extra extractor and firing pin are handy to have around. You can also try polishing the chamber which will help on extraction. |
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i just cleaned my AR and took the bolt apart and the extractor is a POS! the end almost comes to a point, its so whittled away on the end where it should be flat.
there were a few burs where it runs along the slide part so i hit those with a file. i do have the taccom reliability kit but didnt install it yet as i didnt need it on the last bolt really since it was shooting so smooth. one thing i dont understand about the kit is why the firing pins are so different? length is the main thing and it comes with some small round shims? havent read instructions yet but no clue what they would be for? and dont know why new firing pin wouldnt come with a new spring?? |
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All the issues you mention have come up before. Do some research and you will find a lot of discussion on these topics.
I have run many CMMG .22 AR uppers and conversions and not had any problems. Oh, I did wear out a recoil spring and rod but that took about 10,000 rounds. Also, as with any .22 firearm always try different ammo to see if the problem is consistent or if it only occurs with certain types/brands of ammo. Do not over look the effects of your lower. Some hammers and hammer springs can impact the operation of the upper. Its a blow-back design and the power level of the ammo coupled to the resistance of the parts can impact operations. Also, these so-called "mil-spec" lowers we buy are far from being as consistent as their makers would want you to believe. I have had many lowers over the years and can attest to how different they can be. The right combination of parts can make or break a firearm. Sometimes you have to put a bit of effort into getting everything just right. Once you do however you end up with a beautifully functioning machine. Now, all that said, reading a few sentences of a post and trying to give someone a miracle cure is difficult for all but the most gifted. The process of solving problems involves a logical, step-by-step process of determining where the root cause is. Yes, it takes some time but the reward is one learns a lot about how things work along the way and this knowledge can really come in useful in the future. For some of us half the fun of this hobby is learning the "secrets" of what makes things work, and how to fix what doesn't. BTW all my CMMG .22 stuff runs like well oiled Swiss watches. I love them. |
| i got the problem fixed, i took the extractor out and put in my new one to test this morning but when i was pulling the bolt back it was hanging up on the slide part so what it ended being was the extractor pin was to long and rubbing on the rail so i ground a bit of it off and put it all back together and went out a few hours ago and blew through 4 mags as fast as i could go and not one single problem so im a very happy camper once again! |
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Quoted:
i got the problem fixed, i took the extractor out and put in my new one to test this morning but when i was pulling the bolt back it was hanging up on the slide part so what it ended being was the extractor pin was to long and rubbing on the rail so i ground a bit of it off and put it all back together and went out a few hours ago and blew through 4 mags as fast as i could go and not one single problem so im a very happy camper once again! Good job!! Its the simple things that can trip us up sometimes....we just overlook them at first. Enjoy your .22, they are just too much fun. |
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Good job!! Its the simple things that can trip us up sometimes....we just overlook them at first. Enjoy your .22, they are just too much fun. i agree with you there, i originally bought the convertor to use in my .223 upper but it just wasnt as accurate as i hoped for so i bought another upper receiver and a dedicated CMMG .22 barrel and its amazing what a nail driver this setup is now! i have never had so much fun with a .22 rifle! |
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i took my M4 out again today and put about 500 rounds through it and not one single problem!
its running smooth as silk and i couldnt be happier after i shortened that extractor pin, its just to bad the pin looks like crap now after my grind job. i only had a monster vice grip and a course grinding wheel so i might order another pin and hopefully it will be the right length? im really surprised with CMMG customer service being so crappy! been over a week since i sent two emails and never heard back at all?? anyway, like i said im very happy how the convertor is running so thats the main thing! |
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i took my M4 out again today and put about 500 rounds through it and not one single problem! its running smooth as silk and i couldnt be happier after i shortened that extractor pin, its just to bad the pin looks like crap now after my grind job. i only had a monster vice grip and a course grinding wheel so i might order another pin and hopefully it will be the right length? im really surprised with CMMG customer service being so crappy! been over a week since i sent two emails and never heard back at all?? anyway, like i said im very happy how the convertor is running so thats the main thing! You could try posting in the CMMG section. http://www.ar15.com/forums/f_2/145_CMMG_Inc.html |
| I suggest leaving the thread here. Reading about the pin being too long is good for others to know in case they too have issues with a CMMG conversion unit. It's the little things like this that people with issues never think to look. Of course too long of a pin is something CMMG needs to deal with as well so others don't have the same issue. Out of spec parts! |
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nathan from cmmg got back in touch with me today and he is sending out a couple items under warranty so i ordered a few extra things to keep in my ar tool kit since i didnt have to pay shipping.
he was a good guy to deal with and it will be nice when my goodies arrive in case anything happens again i will be ready. |
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Quoted:
i took my M4 out again today and put about 500 rounds through it and not one single problem! its running smooth as silk and i couldnt be happier after i shortened that extractor pin, its just to bad the pin looks like crap now after my grind job. i only had a monster vice grip and a course grinding wheel so i might order another pin and hopefully it will be the right length? im really surprised with CMMG customer service being so crappy! been over a week since i sent two emails and never heard back at all?? anyway, like i said im very happy how the convertor is running so thats the main thing! Curious...where did you get the 500 rds of .22 to blow  ??? Just ribbing you
Glad you got it figured out! |
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went shooting a few weeks ago again and while cleaning the bolt i had another broken spring, not sure why its doing that but i contacted CMMG and they quickly sent me out a couple new springs. im very happy they are on top of warranty replacements but i would like to find out why they are breaking in the first place?
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