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Posted: 11/6/2011 4:55:24 PM EDT
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After cleaning 1 of my ar's , I noticed small pitting/cracking around the firing pin hole . This ar was purchased complete & has less than 1000 rounds thru it , probably closer to 800 rounds. I've never seen this happen so soon in the round count before . Should I contact the manfacturer for warranty replacement or buy a new bolt ? Trying to get clear pics but not sure if thats possible w/ my camera .
Best pics I could get . The pitting is at the 5 , 10 , 11:30 o'clock position . 
edit for pics |
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Quoted:
After cleaning 1 of my ar's , I noticed small pitting/cracking around the firing pin hole . This ar was purchased complete & has less than 1000 rounds thru it , probably closer to 800 rounds. I've never seen this happen so soon in the round count before . Should I contact the manfacturer for warranty replacement or buy a new bolt ? Trying to get clear pics but not sure if thats possible w/ my camera . gas escaping from the primer pocket will pit the bolt face, not a problem unless the firing pin hole becomes pitted |
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An elongated firing pin hole is often a result of a pierced primer. It will often dimple the tip of the FP as well.
I've got one carbine with over 10,300 rounds through it with a badly elongated firing pin hole in the bolt face. It still works. Ran 196 rounds through it this afternoon. I'll replace the bolt when it throws a lug, no sooner. |
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Quoted:
Either a cast bolt  , or the worst machining I have ever seen on a bolt.
Pull the bolt out of the carrier, de-lube it, then post some new photo of it with a couple of different angles please. Also, where did this bolt come from? More pics . My camera sucks . Thanks for taking a look . I also noticed the lugs are thinner than on my other bolts . Also the carrier face isn't exactly smooth . 
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You're probably overly worried about this. I've got an 11.5" blaster that's seen upwards of 14k steel case, almost all of it FA. The firing pin is seriously cratered - you don't need any magnification to see it. Yet the upper runs 100% and that pin does not perf primers. I have no doubt it cratered somewhere along the line b/c of perforated primers (most likely tracer reloads I was using for a time). Also, I've got a number of high-mileage bolts with pits and craters across the face. They look alot worse than the ones depicted in the FAQ, yet they work perfectly. If it ain't broke don't fret.
Sam |
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My blaster upper's pin developed a central crater about two years ago. Nothing subtle about it, even my old eyes can see it without magnification. Overall protrusion is adequate to give 100% ignition, and I don't see perfs on empties now. I imagine I got into some stuff that was giving perfs; probably some of those tracer reloads that were in circulation at the time. Don't know for sure. Stopped using that stuff after a shell broke in the chamber.
Bolt face is hardly perfect, no better than the one pictured. Since then I've put around 5k Wolf through it with that pin and bolt. Upper still runs like a chain saw. Will replace the pin when I start to get FTFires or perfs. Pin and bolt owe me nothing at this point. Sam |
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Hard to tell with any of the pictures really.But I think I see what is being discussed.Looks like there is material flaked/chipped/cut away around the edge of the firing pin port of the bolt face giving a chamfer in the areas indicated in OP.
If this is the case it will likely show on the primers of spent rounds as well. Until clarification can be made with adequate pictures Im not exactly sure.But if the firing pin port is enlarging at the bolt face I think I would contact the manufacutere and let them make the call. |
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