Who Here Really Breaks Bolts?

[OutofBatt3ry]

10's of thousands of rounds....Never broke a bolt. My "no-namiest" BCG was a bolt from Brownell's on my first AR many moons ago. Gun is into the second barrel. Bolt looks good.

Just another data point.

[mooseman]

I saw one bolt break (lugs) from a pool weapon that was fired in full auto a lot and probably had 40k through it. The barrel was well worn out at that point, we were mostly seeing how far we could take it to break to prevent it from functioning without replacing parts once we got it in because this particular weapon looked like it was dropped from the International Space Station. There was barely any anodizing left in most spots with scratches where there was any, the entire gas tube was black, barrel was so worn it was rusting, we were getting about 8 MOA from a bench rest, and it looked like whoever had it thought that doing anything other than dumping CLP on it was illegal. We're talking epoxy levels of grime/dirt/old CLP. At least they kept it wet though, I'll give them credit for that. This thing was truly a testament to how reliable the AR-15/M-16/M-4 platform really is if you keep it lubed and mortar it once in a while because there is so much gunk preventing the movement of the BCG...

For what it's worth, we take 'broken' guns from the field in my agency and refinish them before sending them back into service. The caveat is we inspect them and test them before doing any of this to see exactly what needs to be done, as in do we just need to un**** something a moron did like crack a buttstock from using it as a hammer or some other tool, improperly installed pistol grips (i.e. no safety detent to be found). etc. or does it need to be refinished. Other reasons guns get sent back to us are 'it's all scratched up' (translation: we want the new BCM uppers that you guys are issuing now because A2 FSB are SOOOOO 2002), to the thing can't hold a zero anymore. I'll allow the zero problem, that's always been in well-worn barrels used by FIs in quals, but the rest is almost always end-user error.

If anyone is interested in the refinishing process I could go more into it but it's pretty boring LOL

[Pappabear]

Not yet, but I've only run top tier BCG's. Plus not so big on mag dumps as I learn very little and waste ammo. If I was shooting Uncle Sams ammo, maybe I could break one.

PB

[Labayu]

I've broken 1 bolt lug in 30+ years and it was probably a surplus Colt from the early 70s with untold amounts of abuse before I got it from a demil bin.

I will say that the broken lug sliver did jam the bolt in the extension and it took some seriously weird rifle flipping voodoo and a solid rod being tapped from against it while pulling the charging handle with the edge of a bench to get unstuck.

That upper was mere seconds from meeting the bandsaw after about 45 minutes of that crap.

[davidjinks]

[QUOTE=1168;3025833]TLDR is in the title.



[QUOTE=TMS951;3025678]Absolutely they intend to serialize AR bolts. Honestly quite genius as the bolt is really the Achilles heel of the weapon. They have now made an 80$ fix of a broken bolt replacement need to have an FFl transfer. *SNIP*

I’ve noticed in a couple threads here where people are concerned about bolt life. I’m not interested in debating average life or what the best brand is. I’m also uninterested in “I know a dude that said his cousin in the Unit broke a bolt once.” Just “yeah, I broke one a few years ago; it was a Colt, estimated round count was xx,xxx rounds; ammo used was 262”. Personal experience or direct observation only, please.

To be clear, I’m not mocking anyone’s concern over the potential to break a bolt. I’m just curious about others’ experiences.

I’ll start: Last time I broke a bolt was several years ago, M855, unknown round count, factory Colt M4a1.

I’ve never broken a bolt on my personally owned weapons. At work, that’s a different story. And yes, prior to a new recipe for the M855A1, it was destroying weapons and lowering life expectancy of parts and pieces (That’s all open source BTW).

[ace4059]

[QUOTE=1168;3025833]TLDR is in the title.



[QUOTE=TMS951;3025678]Absolutely they intend to serialize AR bolts. Honestly quite genius as the bolt is really the Achilles heel of the weapon. They have now made an 80$ fix of a broken bolt replacement need to have an FFl transfer. *SNIP*

I’ve noticed in a couple threads here where people are concerned about bolt life. I’m not interested in debating average life or what the best brand is. I’m also uninterested in “I know a dude that said his cousin in the Unit broke a bolt once.” Just “yeah, I broke one a few years ago; it was a Colt, estimated round count was xx,xxx rounds; ammo used was 262”. Personal experience or direct observation only, please.

To be clear, I’m not mocking anyone’s concern over the potential to break a bolt. I’m just curious about others’ experiences.

I’ll start: Last time I broke a bolt was several years ago, M855, unknown round count, factory Colt M4a1.

1168,
What sources do you have that say the government is going to require a FFL transfer for AR bolts?
First I’ve heard about this, but maybe I’m living under a rock.

[vicious_cb]

If you people are that concerned about serialized bolts then the only choice for an uber bolt are the ones using the steel used in Navy aircraft arresting hooks. Unfortunately there are only 2 mfgs who sell bolts like that with limited availability since that steel is only made in small batches and you're probably going to pay $300 per bolt these days.

[TMS951]

If you people are that concerned about serialized bolts then the only choice for an uber bolt are the ones using the steel used in Navy aircraft arresting hooks. Unfortunately there are only 2 mfgs who sell bolts like that with limited availability since that steel is only made in small batches and you're probably going to pay $300 per bolt these days.

Who makes bolts from this material and what is it called?

[lysander]

If you people are that concerned about serialized bolts then the only choice for an uber bolt are the ones using the steel used in Navy aircraft arresting hooks. Unfortunately there are only 2 mfgs who sell bolts like that with limited availability since that steel is only made in small batches and you're probably going to pay $300 per bolt these days.

Curious, but why do you think that vanadium modified 4330 steel would be better than Carpenter 158 or AISI 9310?

[vicious_cb]

Curious, but why do you think that vanadium modified 4330 steel would be better than Carpenter 158 or AISI 9310?

No clue what V 4330 steel is but this is stuff they make uber bolts out of:

https://questekeurope.eu/media/1163/...rdatasheet.pdf

If you contact the company they only make runs of this stuff twice a year which would explain the non-availability of the uber bolts.

QuesTek's Ferrium M54 alloy achieves SAE AMS 6516 specification

August 3, 2011:
SAE International has issued Aerospace Material Specification 6516 for Ferrium® M54™, an ultra-high-strength, high-toughness steel designed by QuesTek Innovations LLC that is also highly resistant to Stress Corrosion Cracking (SCC). SAE AMS 6516 covers the procurement of bars, forgings and forging stock of M54 as a double-vacuum-melted (i.e., VIM/VAR) aircraft-quality alloy, and defines chemistry, thermal processing, properties and other material requirements.

QuesTek designed and developed M54 to be a lower-cost, drop-in replacement for AerMet® 100 (AMS 6532) under Small Business Innovation Research (SBIR) Phase I and II projects sponsored by the U.S. Navy Naval Air Systems Command (NAVAIR). The rapid results of QuesTek's Materials by Design® approach to computationally design, develop and qualify new materials are illustrated in SAE's issuance of AMS 6516 less than 48 months after the specific material property design goals were set under the Phase I project. Under their license from QuesTek, Latrobe Specialty Steel Company began commercially producing and selling M54 less than 32 months after the material design goals were set.

The S-basis procurement minimums for M54 are: 240 ksi yield strength; 285 ksi tensile strength; and 100 ksi-–in fracture toughness. M54 has also demonstrated superior resistance to SCC than competing steels such AerMet 100 and 300M. For economy, M54 contains about 50 percent less cobalt than AerMet 100.

Applications for M54 can include aircraft landing gear, aircraft arresting tailhooks and components, power transmission driveshafts, jet engine shafts and shrouds, drilling equipment, actuators, fasteners, blast tolerant containers, ordnance, sporting goods and other demanding products.

Charlie Kuehmann, President and CEO of QuesTek, commented: "The issuance of SAE AMS 6516 represents an important industry milestone for aerospace applications of Ferrium M54, accelerating the adoption of M54 to reduce costs and improve performance. We thank NAVAIR for their support of M54, and thank SAE's committee and council members for their diligent efforts to issue specifications for new high-performance, engineered materials such as M54."[/I]