• Frank's Lesson's Contest

    We want to see your skills! Post a video between now and November 1st showing what you've learned from Frank's lessons and 3 people will be selected to win a free shirt. Good luck everyone!

    Create a channel Learn more
  • Having trouble using the site?

    Contact support

Garbage bolt?

TonyTheTiger

Like a Boss
Full Member
Minuteman
Feb 14, 2017
5,052
8,235
In the last 2 matches on a new FailZero bolt I've had 4 light strikes. Bolt presumably goes into battery, I hear the hammer drop, eject a live round and carry on. Two of those rounds were found and they had no firing pin dimple.

So I finally look into it and find more crap and brass shavings inside the FP channel than I've ever seen in any other bolt. Enough that the FP was hard to get out and wouldn't slide in freely. Thats when I noticed that the FP hole in the bolt face is oblong.
20191025_202838.jpg

Could the weird oval hole be letting in enough extra junk to slow my FP down? Thats my theory at the moment. Too bad these malfunctions seem to only happen in matches when I can't take the time to properly diagnose things. Very frustrating to say the least, the two malfunctions I got on video really show how it kills the flow.

 
  • Like
Reactions: acudaowner
Sounds like you most likely have the problem figured; send it back to FZ & see if they'll replace it or just buy a Toolcraft DLC bolt for around $50-$55 & move on. They make the DLC coated bolt in both Carpenter 158 & also 9310. Go directly to their website.

Might want to verify a new bolt's headspace to your barrel.............usually not a problem but still worth verifying.

MM
 
  • Like
Reactions: gconnoyer
TTT, I say you are correct with your theory on the larger FP hole. Seen it before with another known brand name. Also, using a brand of ammo that is known for softer brass only adds to the problem.

Two options, as MM said, replace it and hopefully they send you a new one if you go that route. Otherwise, need to clean out the bolt often keeping it free of shavings.
 
  • Like
Reactions: Greg Langelius *
Firing pin is an old Blackheart titanium that I noticed is getting pretty rough where it goes through the cam pin. It's probably getting retired. Cam pin was a FailZero.
 
Yea, those Failzero bolts have a bad reputation. There's a FB group I'm part of that had a long spat of FZ bolt failures every week. Bizzare malfunctions or some shit is the group name. It's just a PSA and Anderson shitshow otherwise, not sure if I would put other FZ products in that bracket but their bolts definitely sucked dick for a minute there.

I like(d) the LMT dual extractor bolt, Enhanced or whatever they call it— it's expensive though. I've seen one fault, but IIRC it was just an extractor spring. Can't go wrong with JP, either.
 
One of the problems with NiB coated bolts. The bolts are made to normal mil-spec and then coated, the coating makes all of the holes smaller. Sometimes the coating hangs on the edge like a drop of water and gets 4-5 times thicker.

As for the firing pin hole, drilling that long hole with a long bit is like trying to drill with a piece of spaghetti.
 
  • Haha
Reactions: Kamerad
Yea, those Failzero bolts have a bad reputation. There's a FB group I'm part of that had a long spat of FZ bolt failures every week. Bizzare malfunctions or some shit is the group name. It's just a PSA and Anderson shitshow otherwise, not sure if I would put other FZ products in that bracket but their bolts definitely sucked dick for a minute there.

I like(d) the LMT dual extractor bolt, Enhanced or whatever they call it— it's expensive though. I've seen one fault, but IIRC it was just an extractor spring. Can't go wrong with JP, either.
Good to know. I'll throw it in the backup parts box and probably never use it again.
 
One of the problems with NiB coated bolts. The bolts are made to normal mil-spec and then coated, the coating makes all of the holes smaller. Sometimes the coating hangs on the edge like a drop of water and gets 4-5 times thicker.

As for the firing pin hole, drilling that long hole with a long bit is like trying to drill with a piece of spaghetti.
And if you look at the picture closely you'll see the NIB flaked off between the FP hole and the extractor. This is the fourth NIB bolt I've had, the first one was from Barnes Precision and has been great for years. The other 3 have been kinda shitty.
 
  • Like
Reactions: bfoosh006
All NiB is not created equal. If you want to stay with NiB, then WMD probably has the best; they are fairly high tech on their surface treatment material & have an advanced version of NiB-X.

But DLC is way slicker & harder than NiB by a goodly margin; Toolcraft & JP are both using it along with a few others here & there.(I use it in automotive applications)

You shoot probably more than most of the rest of us, & that's the direction I'd go for sure. Toolcraft is very reasonably priced & I recently used one of their full DCL coated BCG & bolt....................you can feel the slickness difference. Cleanup on the bolt is easier IMO, too.

I've also been using chrome bolts & carriers from Young Mfg. & Young is a top shelf manufacturer who will stand behind their product & chrome is very slick & hard. And Young also make lightweight carriers.

MM
 
I don't have any interest in staying with NIB, I just keep accumulating them somehow. I think that BPM bolt I mentioned above was sourced from WMD if I remember correctly, maybe thats why its not junk. I do have another rifle with a lightweight DLC Toolcraft BCG that I'm pleased with so far, it's definitely holding up better than NIB.
 
I do have another rifle with a lightweight DLC Toolcraft BCG that I'm pleased with so far, it's definitely holding up better than NIB.

Didn't know TC was making a lightweight DLC carrier as I've not seen them anywhere..............that's why I'm using the Young light carrier.

Where did you get the TC lightweight DLC carrier? (Although they make parts for a lot of name brand sellers).

MM
 
Interesting I have ran a dozen of fail zero complete bcg with zero problems yet. but that can and does happen feces occurs (shit happens) with anything. I've seen mil spec stuff fail and others why? Maybe a bad one maybe some other causes, factors etc. If you send it back to FZ I would be curious to see what they say.
 
Off to double check my Fail Zero bolts... and yeah, that oblong ( almost looks figure 8'ish to me ) FP hole is gonna give grief.

I keep thinking about how un-supported that part of the primer would be.

And I wonder what the channel looks like behind it.
 
  • Like
Reactions: TonyTheTiger
I can't help but notice the irony in the "Fail Zero" bolts doing nothing but failing.

OP, does your BF have some material removed from it, or is that just carbon or some other crap? With that pic, it almost looks like gas erosion from the rim of a primer(s).
 
Firing pin is an old Blackheart titanium that I noticed is getting pretty rough where it goes through the cam pin. It's probably getting retired. Cam pin was a FailZero.

Titanium firing pin? There are very few companies I would trust to make a Ti firing pin. Problem I've had with Ti pins is that they gall on the tip, and will form a cup, then start piercing primers.

There's a certain point where you've gone over the edge with Gucci parts in an AR, and Ti pins is one of those areas I'll never mess around with. Reliability is #1. True Mil-Std pins work.

I've had imitation AR15 firing pins do the same thing, where I thought they were spec, but were not. Formed a cup on the tip that was only visible with magnification.
 
Titanium firing pin? There are very few companies I would trust to make a Ti firing pin. Problem I've had with Ti pins is that they gall on the tip, and will form a cup, then start piercing primers.

There's a certain point where you've gone over the edge with Gucci parts in an AR, and Ti pins is one of those areas I'll never mess around with. Reliability is #1. True Mil-Std pins work.

I've had imitation AR15 firing pins do the same thing, where I thought they were spec, but were not. Formed a cup on the tip that was only visible with magnification.
The tip actually looks great, its the rest of it thats seen better days. If I had to guess I'd say its got between 16-19k on it. I got it because when I first went to a low mass system I was getting slam fires/doubles pretty often. The Ti pin cured it. I've since changed all the components multiple times and just put a mil spec back in with no doubles in the last 250 rounds fired after I started this thread.
 
OP, does your BF have some material removed from it, or is that just carbon or some other crap? With that pic, it almost looks like gas erosion from the rim of a primer(s).
No material removed, are you talking about the discoloration at about 10 o'clock from the FP hole in the pic? Because thats flaked off NIB.
 
No material removed, are you talking about the discoloration at about 10 o'clock from the FP hole in the pic? Because thats flaked off NIB.

Yes, that's what I was typing about. I'm sure you've had some popped primers that did the FP hole damage and caused that flaking. Obviously, most folks don't catch such things for multiple reasons, but the primary reason is that they just aren't examining spent cases.

That sucks dude. I hope you can get into a better quality bolt. I always recommend JP, but I have seen dudes having success with Young's HP bolts too. IF ToolCraft is making HP bolts, I'd consider one from them as well.
 
Yes, that's what I was typing about. I'm sure you've had some popped primers that did the FP hole damage and caused that flaking. Obviously, most folks don't catch such things for multiple reasons, but the primary reason is that they just aren't examining spent cases.

That sucks dude. I hope you can get into a better quality bolt. I always recommend JP, but I have seen dudes having success with Young's HP bolts too. IF ToolCraft is making HP bolts, I'd consider one from them as well.
I have a few spare bolts lying around, I swapped one in and its been good for now. I'd still like to get a good one like a JP just because I'm having a hard time remembering where all these bolts came from or how many rounds are on them. For all I know they all need a rebuild...
 
Anyone use the Young HMB bolt? The cam pin hole not going all the way through seems like a logical way to manufacture a bolt.

Yes, I have a couple. One in a standard carrier & one in a lightweight carrier, both are Young carriers.

Not really a lot of rounds through them yet, but so far so good. Young is my preferred bolt & bcg, going with another one as I'm putting together parts for a new upper.

Bolts are waited listed right now, so if you want to try one, get on the list for the next batch. Really nice people to deal with too, as a bonus.

MM
 
  • Like
Reactions: TonyTheTiger
Well, 5-600 rounds on the backup bolt with no malfunctions and the FP channel is still clean. While not a long term test yet, I think I've solved the problem.
 
@TonyTheTiger off-topic but whats your favorite match pistol(s)? Post up in the handguns pic thread if ya haven't
I'm sure its buried in the big handguns thread somewhere, in the 3 gun thread somewhere also.
I'm partial to my old CZ Tac Sport. 1.4lb trigger, 23 round mags and all the accuracy I can handle keep me satisfied. All my buddies have moved up to 2011's, and they're nice, but I've become attached to it and don't feel a need to try anything else. Except maybe the new Dan Wesson X..
Gun porn, just because.
20190319_175147.jpg

_4B_1372-(ZF-2970-20976-1-007).jpg
2019_06_23_NVTG2019_7255-(ZF-4676-93328-1-001).jpg
 

Attachments

  • ZF-2970-20976-1(1).zip
    7.4 MB · Views: 83
  • Like
Reactions: deersniper