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Posted: 9/25/2015 10:09:22 PM EDT
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Thinking about it, the headspace may be off since the extractor doesn't pick up the loaded round in the chamber. It only picks it up once it was slammed home and fires without a pull of the trigger.
Bad barrel?? Working on pics. ETA here are the pics For reasons listed above with slam firing, I am not inserting a live round with the bolt in the gun. Spent round from a 22 bolt 
Just the collar 
Loaded round with only the collar on 
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Some conversion kits and dedicated uppers will not cycle standard velocity or subsonic ammo without modifing the recoil spring or hammer spring.
The conversion bolt might be getting to much fore and aft movement. TACCOM3 sells a plug to place in front of the buffer to keep the conversion bolt from moving inside the upper. You can also tape a couple of quarters onto the end of the buffer to see if this helps. I have had very good functioning with Federal 36 grain bulk HP, WW 555 bulk packs and CCI Blazer ammo. Most of the early CMMG & Ciener style conversion bolts would not extract live ammo out of the chamber. Newer CMMG conversion bolts feature a modified extractor to pull live rounds out of the chamber. A lot of 22 rimfire extraction is caused by the rearward push when the round is fired. Even though a dedicated upper will not extract live or dummy ammo doesn't mean it won't function when firing live ammo. |
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This topic has me very curious. I built two completely different dedicated .22LR and have not had a problem with either one. Both did use a CMMG bolt and collar but different barrels, uppers, lowers and triggers. I did not use a TACCOM spacer in front of the buffer either. As soon as I get home from work (very soon I hope) I'm going to look at my bolt/collar set up to see if it looks like yours.
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Another issue which occurs for some users of conversion kits and dedicated uppers are notched hammers. It really depends on the individual lover and hammer whether this is an issue. Some notched hammers snag on the bottom rear of the conversion bolt below the firing pin. There may be visible wear marks where the hammer is catching on the under side of the bolt.
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Quoted:
Get a Taccom or CMMG barrel and collar. Spikes put out crap. It either ran or it didn't. Feed ramp has always been wrong. The barrel has too much work done to it. Don't waste your time and money tring to get it to run. It won't Dave N I thought a CMMG collar wouldn't work on a Spikes barrel. I bought the barrel under the guise of being NOS, for a lack of a better word, so if the barrel has been buggered before I got it I will return from where it came and try something else. |
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Quoted:
Get a Taccom or CMMG barrel and collar. Spikes put out crap. It either ran or it didn't. Feed ramp has always been wrong. The barrel has too much work done to it. Don't waste your time and money tring to get it to run. It won't Dave N Curious what you mean in saying that the barrel has too much work done on it. |
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The ramp looks excessive.....is that were the case is failing? That would be a case support issue and the barrel would be bad at that point. HOWEVER......
As a rule, if you are getting blow outs and or otherwise case failures......one of 2 things are bad. 1) the recoil spring is too weak.....easy fix, get one of ours. 2) the firing pin is capable of firing the round more than .06" out of battery......clean up the chamber....keep it clean and remove about .030" off the head of the firing pin.....basically, when you push the firing pin forwar, you'd like to see about .010 to .020 sticking out....or only about .025" of the tip of the firing pin sticking out the front (not out the bolt face.....out the headspace) TIm |
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Quoted:
Curious what you mean in saying that the barrel has too much work done on it. Quoted:
Quoted:
Get a Taccom or CMMG barrel and collar. Spikes put out crap. It either ran or it didn't. Feed ramp has always been wrong. The barrel has too much work done to it. Don't waste your time and money tring to get it to run. It won't Dave N Curious what you mean in saying that the barrel has too much work done on it. Someone, be it Spikes or whoever, has ground the barrel to meet the too short feed ramp, which is already at too much of an angle. It may run better with a shorter 36 gr. hollow point. But the case is still not supported enough on the bottom. And like Tim said, if crud builds up around the chamber, which will happen quickly using Remington, it can keep the round from fully seating, causing an out of battery discharge. Dave N |
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My CMMG factory dedicated .22 upper is picky about what I feed it.
When I took it out the first time, I was having feeding issues (not chambering all the way), which led to a few FTFs and one out-of-battery ignition. This was with Remington, if I remember correctly. Anyway, it seems that mine does prefer plated ammo, but last time I took it out it didn't hiccup with either Federal or CCI lead round nose. I would assemble a variety of ammo and see if the results are consistent. |
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