why would bolt break?

[babaganoush]

Mine is fine, bought around April. It's been used only with reloads that are at or below max pressures, and unsuppressed. Some of your statements indicate your frustration, and I understand. I just don't see where you can make such a broad brushed generalization about LBC bolts ("Nothing we can do will keep them from breaking") based on so little information.

[cory]

Mine is fine, bought around April. It's been used only with reloads that are at or below max pressures, and unsuppressed. Some of your statements indicate your frustration, and I understand. I just don't see where you can make such a broad brushed generalization about LBC bolts ("Nothing we can do will keep them from breaking") based on so little information.

If you've followed this thread from the beginning there's several LBC bolts that have broke recently. This isn't an isolated incident.

[bigbear_98]

If you've followed this thread from the beginning there's several LBC bolts that have broke recently. This isn't an isolated incident.

Yes. Not every bolt will be bad but they do have some bad batches. As for sources, I talked to a lot of local smiths and machinists. They wouldn't give me their sources. I'm not bad mouthing lbc. I am suprised that they said "can't be run suppressed". They should tell you that before you purchase, but not really frustrated with them outside of that. I just want to get to the bottom of the problem. I was told don't stress about it, buy a different bolt and try to return the one I haven't used yet.

[babaganoush]

If you've followed this thread from the beginning there's several LBC bolts that have broke recently. This isn't an isolated incident.

Well, actually, I have followed this thread from the beginning. By my count, exactly two people have mentioned having a broken LBC bolt. The OP, Dammitman, first mentioned at post #3. Bigbear_98, mentioned his at post #111. The rest of the discussion where LBC bolts are mentioned, is back and forth Q&A, mixed with speculation. Considering how many times this particular bolt has been mentioned, one might come away with the impression that "several" may be involved, but there were, in fact, only two.

In my book, two does not equate to "several". Not looking for an argument, Cory. Just letting you know how I see it.

Yes. Not every bolt will be bad but they do have some bad batches. As for sources, I talked to a lot of local smiths and machinists. They wouldn't give me their sources. I'm not bad mouthing lbc. I am suprised that they said "can't be run suppressed". They should tell you that before you purchase, but not really frustrated with them outside of that. I just want to get to the bottom of the problem. I was told don't stress about it, buy a different bolt and try to return the one I haven't used yet.

Again, we're going from two reported incidents to entire "bad batches". I don't see any dots being connected, here. BB - You're citing unnamed sources, who won't tell you who their sources are, and posting on this board as if it were confirmed fact. This, under even the lightest scrutiny, amounts to a rumor, and nothing more.

It's too easy to get revved up over this kind of stuff, and it does nobody any favors when one makes mountains out of molehills.

[bigbear_98]

Well, actually, I have followed this thread from the beginning. By my count, exactly two people have mentioned having a broken LBC bolt. The OP, Dammitman, first mentioned at post #3. Bigbear_98, mentioned his at post #111. The rest of the discussion where LBC bolts are mentioned, is back and forth Q&A, mixed with speculation. Considering how many times this particular bolt has been mentioned, one might come away with the impression that "several" may be involved, but there were, in fact, only two.

In my book, two does not equate to "several". Not looking for an argument, Cory. Just letting you know how I see it.



Again, we're going from two reported incidents to entire "bad batches". I don't see any dots being connected, here. BB - You're citing unnamed sources, who won't tell you who their sources are, and posting on this board as if it were confirmed fact. This, under even the lightest scrutiny, amounts to a rumor, and nothing more.

It's too easy to get revved up over this kind of stuff, and it does nobody any favors when one makes mountains out of molehills.

That's fair. I'm just sharing the information I gathered. Do with it what you want.

[cory]

Well, actually, I have followed this thread from the beginning. By my count, exactly two people have mentioned having a broken LBC bolt. The OP, Dammitman, first mentioned at post #3. Bigbear_98, mentioned his at post #111. The rest of the discussion where LBC bolts are mentioned, is back and forth Q&A, mixed with speculation. Considering how many times this particular bolt has been mentioned, one might come away with the impression that "several" may be involved, but there were, in fact, only two.

If I remember correctly the OP after breaking an LBC bolt, bought a new one and broke that one too.

[NugginFutz]

I see baba's point - I think he's just trying to help us stick with the facts, and avoid any hyperbole.

bigbear - thanks for your insights, and for sharing your experience. Very informative.

[babaganoush]

If I remember correctly the OP after breaking an LBC bolt, bought a new one and broke that one too.

On a re-read, I agree with you, and stand corrected. I missed the post where he reported a second bolt breaking. This, of course, changes the numbers, somewhat. I am still not convinced there is an epidemic here, and would like to hear more from the OP on his test results with the different upper.

[dammitman]

i am working on it. i have not been able to perform controlled tests yet and although i think i know whats happened, i really have to get the time to be sure i figure out for sure. i dont see this happening till into the new year. holidays seem extra busy these days.

[noone]

I have had two broken bolts with Grendels. After the second break, I contacted Harrison at Ar15performance to inquire for solutions. My Alexander Arms rifle didn't have any issue breaking bolts. The other rifles had different upper recievers, and I was told that many AR15 uppers don't aren't manufactured truly "square" where the barrel extension goes into the upper receiver. When a barrel extension is tightened onto an out of square upper, uneven pressure is put onto the barrel extension, then onth the bolt's lugs. The fix is the square the face of the upper reciever where the barrel extension fits.

After having this work done on two uppers, I have fired thousands of rounds, and not had any more broken bolts. To be sure, my two incidents do not make a statistically significant sample, and only provide anectdotal evidence. But I'm happy that ever since I had the upper receivers squared up, I have not had any more broken bolts.

[bigbear_98]

I have had two broken bolts with Grendels. After the second break, I contacted Harrison at Ar15performance to inquire for solutions. My Alexander Arms rifle didn't have any issue breaking bolts. The other rifles had different upper recievers, and I was told that many AR15 uppers don't aren't manufactured truly "square" where the barrel extension goes into the upper receiver. When a barrel extension is tightened onto an out of square upper, uneven pressure is put onto the barrel extension, then onth the bolt's lugs. The fix is the square the face of the upper reciever where the barrel extension fits.

After having this work done on two uppers, I have fired thousands of rounds, and not had any more broken bolts. To be sure, my two incidents do not make a statistically significant sample, and only provide anectdotal evidence. But I'm happy that ever since I had the upper receivers squared up, I have not had any more broken bolts.

Just as a note, I had/have squared my receivers with the tool from midway per the accurate ar15 thread. Both of the rifles I just built are on aero precision uppers and were true.

[bigbear_98]

Alright men. I have 340 suppressed rounds on my Maxim bolt. When I cleaned it the other day, it doesn't look like anything is wrong with it. A little finish wear, but looks good to go. All of the finish wear is consistent and nothing showing uneveness in the receiver (which I expected since I trued the face). All 387 shots fired is factory Hornady SST 123 grain from two lots. Remember the LBC bolt broke after 45 rounds.

[Tedward]

Alright men. I have 340 suppressed rounds on my Maxim bolt. When I cleaned it the other day, it doesn't look like anything is wrong with it. A little finish wear, but looks good to go. All of the finish wear is consistent and nothing showing uneveness in the receiver (which I expected since I trued the face). All 387 shots fired is factory Hornady SST 123 grain from two lots. Remember the LBC bolt broke after 45 rounds.

So it sounds like he did a good job making them then. I have had great success too and if you notice on his bolts, the edges came eaised or rounded off, not sharp square corners.

Keep pounding on it, I think it can take the use and even abuse.

Glad to hear everything worked out.

[woohoo]

Paul,
Why are these Grendel bolts still breaking. You think it has anything to do with hoop strength or is it just how thin the material is around the recess of the bolt? I wonder why Stoner designed the 5.56 bolt to be the size it is and why everyone else is putting bigger cartridges in the same size bolt. You would think they would have increased the size of the bolt in the same proportion that the bolt face was increased. If they had the bolts wouldn't be breaking. I have to assume with the actual breakages reported over the years the rim of the Grendel may be a little to big for a 5.56 bolt.

[cory]

Paul,
Why are these Grendel bolts still breaking. You think it has anything to do with hoop strength or is it just how thin the material is around the recess of the bolt? I wonder why Stoner designed the 5.56 bolt to be the size it is and why everyone else is putting bigger cartridges in the same size bolt. You would think they would have increased the size of the bolt in the same proportion that the bolt face was increased. If they had the bolts wouldn't be breaking. I have to assume with the actual breakages reported over the years the rim of the Grendel may be a little to big for a 5.56 bolt.

Me thinks, someone has trouble reading this thread and others. :?