I have a .264 LBC from Les Baer. I have had it for a couple years and had very good results with it for the first year, then I broke a lug off my bolt. Every since then I am breaking bolt after bolt, I am on my sixth one and I have even sent it back to Les Baer whom returned it with a new bolt at no cost to me. 28 rounds later, another broken bolt!! I am not running hot loads, this load was a 123gr. Amax behind 27.5gr XBR 8208, about 2420 on the crono. It still shoots great but only for about 30 rounds and then it breaks a bolt. It was head spaced by Les, I am using brand new brass, I checked and I'm not seating any where near the lands, I can't and still fit it in the magazine, and I am using 1.2gr les powder the I used with the original bolt which had many more rounds fired. I don't know what else to do.
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If you are breaking off the same lug there might be an issue with the barrel extension. Can you try a different carrier and cam pin with your new bolt. It might be that you are not getting a 100% lock up of bolt lugs to the extensions lugs. A new bolt should wear evenly on all lugs except the one across from the extractor. this one should make little or no contact. Are you resizing your brass correctly so the bolt can lock up freely. Take the upper off to do this test. Put your resized case in the chamber and push the carrier with your thumb to close the bolt so it's flush with the back of the upper. Now pull back on the charging handle to eject the case. If it pulls back with normal pressure then your cases are resized properly. If it pulls back very hard or locks up tight you have to set the case shoulder back so the bolt works freely. Your bolt may not lock up right if the cases are to long to chamber easily. This puts a lot of stress on the lugs as they might not get 100% contact.
Greyfox
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Nimrod Wrote:I have a .264 LBC from Les Baer. I have had it for a couple years and had very good results with it for the first year, then I broke a lug off my bolt. Every since then I am breaking bolt after bolt, I am on my sixth one and I have even sent it back to Les Baer whom returned it with a new bolt at no cost to me. 28 rounds later, another broken bolt!! I am not running hot loads, this load was a 123gr. Amax behind 27.5gr XBR 8208, about 2420 on the crono. It still shoots great but only for about 30 rounds and then it breaks a bolt. It was head spaced by Les, I am using brand new brass, I checked and I'm not seating any where near the lands, I can't and still fit it in the magazine, and I am using 1.2gr les powder the I used with the original bolt which had many more rounds fired. I don't know what else to do.
NR:
I bet you have more broken bolts than I do! Never broke one in any other AR type of rifle. Have broken six or seven since shooting the Grendel. However, only two of them were true Grendel Bolts sold by AA. Three were 7.62 X 39 bolts and two more were 5.56 bolts opened up to fit the Grendel. Surprisingly, the opened up 5.56 bolts lasted just as long as the true Grendel bolts. Not so with the 7.62 X 39 bolts. Their life span was pretty poor.
You will find that all the lugs are the same ones. Next to the extractor. Greyfox says there may be an issue with the barrel extension. Could be but that was the issue with only one of mine -- an 28" model sold by CSS when they were together with AA. The rest are simply because that part of the bolt is too thin to take as much abuse as something like a 5.56 or 6.8.
However, in my case this spanned four or five different uppers. In your case, only one upper. So, could be poor quality bolts and could be something like what Greyfox says.
Get hold of Les Bear again as something is seriously wrong.
LR1955
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Nimrod,
I'll direct you to my thread from last week.
http://www.65grendel.com/forum/showthrea...lt-problem
I built a 5.56 and a lug was interfering with the barrel extension (BE). Read how my procedure in installing the barrel caused this. But I could look down into the BE as I brought the BCG forward and I could see the bolt nick the BE. Yours might not be nicking the BE like mine did but there could be a little more interference than normal.
Do you have any sticking problems with charging or getting it into battery?
Mine was really tough to get into battery and to charge.
Notice in my thread that the feed ramps were just off. This should've tipped me off that there was an alignment issue between the BE and lugs of bolt.
But this sounds like too much interference with the BE.
Nimrod!
Are you affiliated with what used to be Nimrod rifles- The tack driving 10/22 with the bloop tube rifles? I've wanted one for years.
I purchased a high end bolt gun, Sako 75 SS, I did the degrease, sharpie the lug faces test to see if it was square. I found a small burr/gall on one bolt face, contacted Sako and it was promptly replaced it with a hand picked tack driver- through Stoeger.
Have you tried marking the rear of the bolt lugs and fire one round?
It could be telling.
No this is not me.
PinkVapor Wrote:Nimrod!
Are you affiliated with what used to be Nimrod rifles- The tack driving 10/22 with the bloop tube rifles? I've wanted one for years.
I purchased a high end bolt gun, Sako 75 SS, I did the degrease, sharpie the lug faces test to see if it was square. I found a small burr/gall on one bolt face, contacted Sako and it was promptly replaced it with a hand picked tack driver- through Stoeger.
Have you tried marking the rear of the bolt lugs and fire one round?
It could be telling.
I will try all the above advice. I don't have any sticking or feeding problems, no disernable problems other than braking bolts. I talked to Les and he told me I need to load down to a max of 2350 fps at the muzzle. He says his barrels are very tight, hinge higher pressures, so he is sending me another bolt and I am going to follow his advice, along with all yours to do my own quality control checks. Thanks for the replies.
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Is the upper receiver face square?
Drifter
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There is something wrong with that rifle. No rifle should be breaking bolts like that. My guess is that something isn't square, and the lugs are not locking correctly, but thats impossible to check without proper equipment.
LBC ammo is loaded significantly hotter than 2350, so I would try their ammo. If you are breaking bolts with their ammo, you have a real issue.
You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live. - John Galt
I don't know how to check to see it is square or not, I would hope it is since it is a Les Baer custom, I think I will order some of his ammo and run it to see if I have trouble, I agree that the factory ammo is hotter than 2350, but he said they are using different powders that produce less pressure. I don't understand that though as it would seem to me that pressure is what pushes the bullet down the barrel, more pressure more velocity it would seem to me. My original bolt had over 1,000 rnds of significantly hotter loads then 2350. Every since then it is bolt after bolt even while I continue to step back on my loads. As I said before I sent the rifle in last time to be checked out and Les cleared it and sent it back. I am at a loss and at 2350 out of my 20" barrel I can't very well take advantage of what the Grendel has to offer.
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Ask to speak with LB himself.
Drifter
Already have, that is what is cool about his outfit, when you have trouble it is him you talk to. All the info I have gotten from the company has been from him.
I spoke with the folks at AR15 performance about my issue. I am thinking that my rifle is about to be on its way to them, first to be checked out and second to be fitted with their Super Bolt. Any thoughts on going that direction?
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Nimrod Wrote:I spoke with the folks at AR15 performance about my issue. I am thinking that my rifle is about to be on its way to them, first to be checked out and second to be fitted with their Super Bolt. Any thoughts on going that direction?
I would think that Les Baer would like the chance to see your rifle, and recheck it in light of your continuing issues. I would also expect that he would want to correct the issue for you, without charging what you will pay AR15 Performance. My general rule is that the people who built it should fix it! Since you went 1000 rounds before breaking your first bolt, and since can't even get to 50 rounds, there are only a couple explanations:
1) Something has changed in the rifle.
2) The bolt quality has dropped.
1 and 2 are Les Baer issues.
3) Your ammo is signficantly hotter than you think it is. I'm assuming that you used the same recipe in the rifle before your first bolt broke, so this probably isn't the issue.
AR15 Performance does not show the 264 LBC bolt in stock, (out of stock, no backorder) and remember that their bolt is a .125 depth bolt. I believe that Les Baers are headspaced for Grendel bolts, which have a face depth of .136. So unless you are going the new barrel route, using an AR15 Superbolt isn't an option.
You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live. - John Galt
What are the differences between AA's regular and "hard use" bolts?
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bwaites,
There are 2 types of 264 LBC bolts with different depths. I just bought one and it is 0.134" deep. I measured it this week.
Is it possible that the wrong type LBC bolt is being used?
That is a basic question and I'm certain this is not the case if LB looked at it, you would think the head spacing was checked with the old and new bolt.
Just thought I'd ask or raise that possibility.
Surely the 0.002" difference in depth from the Grendel Bolt to the LBC bolt would cause these issues. Correct?
There should be enough tolerance in the headspacing to accomodate this.....I think.
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Nukes Wrote:What are the differences between AA's regular and "hard use" bolts?
Most significant difference is that the hard use bolt has a cutout in the lug opposite the extractor to allow more even distribution of thrust on the bolt.
You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live. - John Galt
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bwaites,
is the cutout on the corner of the lug?
I'm not seeing why that would distribute load on the bolt more evenly?
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Keep The Change Wrote:bwaites,
There are 2 types of 264 LBC bolts with different depths. I just bought one and it is 0.134" deep. I measured it this week.
Is it possible that the wrong type LBC bolt is being used?
That is a basic question and I'm certain this is not the case if LB looked at it, you would think the head spacing was checked with the old and new bolt.
Just thought I'd ask or raise that possibility.
Surely the 0.002" difference in depth from the Grendel Bolt to the LBC bolt would cause these issues. Correct?
There should be enough tolerance in the headspacing to accomodate this.....I think.
LBC itself uses the Grendel SAAMI standard bolt, unless something has changed. That is the the bolt with .136 face depth. (.134 is probably within the tolerance spec).
The .125 face depth bolts were a compromise that started when standard Grendel bolts were scarce. This whole "Type 1" vs. "Type 2" thing started because Black Hole Weaponry initially couldn't get .136 bolts and decided to chamber with the .125 face depth. When they started getting SAAMI bolts, they had to differentiate between the two, and started using the Type 1/2 nomenclature. The rim of the Grendel case is thicker than 5.56, and that extra depth allows a proper extractor geometry.
Some builders continue to use the .125 bolts, but thats because they can get them, not because they are optimal. I have no idea why ARPerformance chose to use that face depth, since there is a SAAMI standard, and someone is going to get hurt swapping bolts and not knowing. A .125 bolt won't close on a Grendel chamber, but a .136 will on a .125 chamber, and thats a lot of headspace difference.
You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live. - John Galt
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KeeptheChange --- Its in the back of the lug. You can see it if you go to AA's web site and look at the hard use bolt in comparison to the standard. It allows the lug to flex minutely, allowing more even distribution of the pressure.
You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live. - John Galt
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