How come Ron manages to get 60,000+ rounds out of Colt M4 bolts, yet by all accounts M4 bolts don't last past 10,000 rounds?

Hey, I've got a really stupid idea!
How about everybody with a personal agenda and axe to grind posts about how they are offended by somebody else's stupid opinion about some brand of gun!
That's sure to get this thread blocked, despite the fact that the OP and 99% of posters have managed to be supportive.
JFC.  Rent a room.

Apologies if this has been asked and answered, but any FN commercial ARs on the line?

The only FN on the line that is currently in service AND being sold commercially for us is the semi-auto M249. We haven't purchased any of the FN M4/AR15 rifles at this yet as we still have plenty of other M4's on the line.

V/R
Ron  

Right on, thanks man. Appreciate the thread!

Pretty please, Ron?
I'm starting to think he doesn't like Steyr AUG guys...
That or he likes 'em too and doesn't want to drive the price up with information of how long they last.

What he said...  I don't know how he gets that much use out of those bolts, but I have suspicions.  I'm pretty sure that Ron's armorers don't replace bolts until they actually fail, rather than replacing them when they have certain characteristics, such as pits on the bolt face.  That's part of a quarterly check in the current TM, so I believe that there are tons of "unserviceable" bolts being replaced that Ron's guys would keep on the line.

Just a hunch, but I bet it's in the right ballpark.

Incredible read. Thanks for sharing.

I think your on the right track.  Another question, what ammo is he using?

Edit: On page 01 Ron stated that he was currently using Wolf Gold, but that Magtech and Privi had been used before.

On page 01 it is also stated that most bolts seem to see issues around 20,000. There may be some bolts running to 60,000, but I don't have time to run through the last 23 pages to point them out. An average of 20,000 rounds before issue is still pretty damn good.

That would be a very logical explanation.  

We only replace them when the the shear/crack a lug. Other than that, they stay on the line.

V/R
Ron

For at least the last year and a half or even two years we've only used Wolf Gold .223. I love this stuff as it burns super clean and seems like standard M193-type load but it's listed as .223. It's fair to say we've put over 2 million rounds of the Wolf Gold down range and the mag loaders have said they've never had a round that was loaded with bullet upside down or a backwards primer. I can't say that about the other ammo we've used.

V/R
Ron

I continue to be amazed at the wealth of information on this forum and Ron's work/contribution to the value here is extremely appreciated.  Thank you to you and your team!  Very nice work!

But waitahold it.  

The issue we hear all the time isn't that AR bolts are replaced due to schedule at "10,000" rounds or some such, but that they FAIL {as in busted lugs} at some figure around 10,000.

Ron's experience indicates AR bolts last a LOT longer than many "experts" {especially those of military origin} suggest they do.

Now...........................................

Is it possible that claims of earlier failure of AR bolts are accurate, but caused by exclusive or nearly exclusive use of military ammo that may be running at higher average pressures?  Because a lot of civvy ammo runs at lower-than-spec speed and likely pressure as well.

We might expect there to be a greater incidence of wear and failure if a rifle is subjected to an exclusive high round-count diet of 55+k psi of M855 vs 45k or 48k of some civvy-made stuff.

I'd love to know what the actual average working pressure of Wolf Gold is.  I'm guessing that Wolf 55 grain isn't running at 3250 fps or anywhere near it and neither are the pressures commensurate with milspec ammo that is.  Somebody with a chronograph should be able to help us with the muzzle speed.

That makes perfect sense in your situation.  For combat weapons, not so much - thus the TM's inspections and replacement when failure is "impending."

Thanks for the confirmation, Ron.

I am on the boat right now and it will take about 3 days to download all 24 pages so if this has been hit already, I apologize but have any of the MWS/OBR/SR25s .308 types been thru the same shooting schedule as the other guns?

GI armorers replace bolts that display specific features indicating failure is imminent.  Pitted bolt faces, stress indications at bolt lug roots, etc., are such features.  In a COMBAT weapon, having a bolt fail is NOT AN OPTION, while Ron's guns are purely for entertainment, in a situation where nobody's shooting back.

The "experts" call for bolts to be replaced before they fail, so that they do not fail in a critical situation that will cost lives.  THAT is the big difference.  Ron describes the Wolf Gold as seeming to be pretty much M193 ammo, so it's almost certain that his guns run full power, full pressure ammunition.  His experience is not translatable to combat weapons, though it DOES translate to civvies shooting range toys (or even competition guns).

He also, doesn't seem to be shooting super high pressure stuff like M855 and M855A1....

Commercial ammo generally doesn't average above 58,000 psi, MIL-SPEC M855 ammo can peak at 64,70 psi, M855A1, allows for maximum pressures up to 66,000 psi.

Thanks again Ron for all the feedback.

My thoughts exactly.

Seems like a good working idea.  Also, there is a bell curve to most of life events; I suspect some bolts in a run, of a particular metal, of a brand, yada yada, will fail at different points along the curve.  Some few prematurely, some positively geriatric, and others somewhere where you might imagine they would just wear out.

Things wear out and break, lube is good, heat is bad, and water is the universal solvent.  Rust never sleeps.

Really good learning experience in this thread. Thank You.

Current lots of M855A1 have something like 54,500 psi or something along those lines.

If wolf gold is akin to M193 then you're still looking at 52,000 PSI.

One of the hardest parts of hiring GI armorers is trying to "ween" them off from GI mentality. My staff were armorers when still active service so they always wanted to replace anything and everything with the slightest bit of wear. If a weapon jammed, it's almost like they were programmed to blame with the bolt carrier group and replace it. If I had Uncle Sugar's budget it wouldn't be such a big deal but that's a luxury we definitely don't have. They would say the exact same thing about the 10,000 round mark of replacing the bolt but I would tell them.. "show me the wear and why it needs to be replaced". Their responses were almost exact with "well, the TM says we need to replace it".

When we first started, we almost went under because of finances. My first three armorers had all just recently got out of the service. Two were from the Army and one from the Air Force. The Army guys knew ground guns inside and out and my Air Force guy knew (he always used AF designations for weapons) the M-134, M240, M2HB and M3. I would catch them dead-lining M249 and M240 barrels, M4 bolt carrier groups (just replace the whole group) and even trying to replace the barrels on the M-134 (NOT cheap or easily found when your email doesn't end with .gov or .mil). The barrels for the M-134 "minigun" gauged like new and had no noticeable wear but my armorer Trimble (I really do miss you kid) almost lost it when I told him we weren't replacing the barrels at the required interval. He said the same thing about our bolts AND if one had an issue, they ALL had to be replaced. That is one example of my guys not being able to transition to civilian life easily. If you're reading this Trimble, you looked you were going to have a nervous break-down when we said that the the parts are staying in the weapon. Those same barrels and bolts (which we changed one bolt group at a time NOT in accordance with mil-spec maintenance) continued to run and run... and run.

We didn't have the money to buy new parts, by new guns, do payroll, pay utilities, buy ammo, etc and my armorers learned really quick the difference between working for Uncle Sugar with a big wallet or me, who was not even able to pay myself when we opened.

I send my armorers and assistant armorers to get trained on the various weapon systems and that includes Barrett, Sig, Colt, Glock, Berretta and even the M-134 (there are others but I can't think of them right now). My armorer Trimble knew the M-134 like the back of his hand but was moving away for college. He trained each armorer on the weapon system but my concern is that if there was ever a catastrophic accident with the M-134 and I didn't have anybody certified on it, it could open me up to liability that would extend beyond insurance coverage. There is a company that certifies armorers (not DillonAero) on various weapon platforms to include the M-134. Our instructor was a former 160th SOAR guy and he did explain quite a few things to my guys but it was pretty funny for him to tell us that our weapon shouldn't be running because of how many rounds we had through it. Our barrels should have been replaced years ago, our bolts shouldn't be working, the feeder/delinker should have been replaced by a certain amount of rounds, etc. By the end of his third day, it was funny to hear him tell us how the TM's didn't apply to our range and everything he was taught while in about replacing bolts, barrels, feeder/delinkers functioned perfectly.

That being said, I completely understand why there's a difference between keeping a weapon mission-ready as opposed to range-ready. My RSO's will come back with a weapon and say "it's not picking up a round", "it's light-striking", "fail to feed/extract", etc and that's not a luxury that most who depend on that weapon for their life has.

Lastly, that bolt that lasted that long the Colt was an EXCEPTION, not the rule. We've lost other Colt bolts all in the same time frame as the Daniel Defense, LMT and even the PSA.

V/R
Ron

edited: because I don't type quite like I hear it in my head ;-)

Thanks for all the info Ron, I really appreciate it.

+1, Ron. Great info. Please keep it coming.

I will never gain the knowledge gained from this thread based on my own volume of shooting.
Great source of info.

Thank you Ron, for your continued contributions.

Outstanding info.

thank you!

You and me both!

Great points, Ron.  Your customers are out there to have fun and make a whole lot of noise.  A GI armorer's "customers" need to be able to stake their lives on their weapons.  There is a HUGE difference between the two.

Thanks again!

My experience has been that 10k is in no way a recommended or real world service life, so I'm not sure who's accounts these are.

Everything I know about M4 bolts is 20k+.

He also says above that the bolt that lasted 60,000 was the exception to the rule, and that the Colt bolts don't last any longer than the others they use.

This is the best reference thread since the similar M4/M16/AR15 parts breakage thread. That thread was basically multiple users and trainers stating what was likely to break, this is one users experience with multiple manufacturers weapons. While slightly different perspectives, both are awesome.

Thanks for taking the time to provide this invaluable resource Ron/HD.

Great info . Good to hear what a lot of folks already know. Colt parts is what everybody else is judged against . I've seen them all fail at one time or another. Just throw a couple spares in the Parts center  and most will be good to go for along time. WD

I am moving out to Las Vegas next month and I will definitely be visiting your range. Shooting full auto isn't the most exciting thing for me after years in the military as a machine gunner, but a trip will likely be my go-to when I have my non military friends in town to visit.

tagged

I don't disagree at all that 60k is very high - I'm challenging the idea that 10k seems to be an "accepted" number for bolt life.

Let me put this in perspective based on my experience;  I've been involved in numerous weapons trials for Governments both overseas and here in the US in both 7.62x39 and 5.56 and the party doesn't get started until 15k at a minimum.  If a major component of the weapon system breaks before 15k, pack your shit and go home, you're done - and largely those rounds are shot in 2-3 days.  I've literally never seen it happen.

Agree with everybody's comments re: this legendarythread.jpg

Interesting. Thanks for the info.

I see 10k as more the super conservative safe bet for bolt life. For example let's pretend 90% of bolts last to 30k rounds, 5% fail at 20k, 4% fail between 10k and 20k, and 1% fail under 10k.  If you have a rifle you're betting your life on, it's probably good practice to replace bolts at 10k rounds.  On the other hand, if you run a commercial shooting range where an occasional malfunction is more a nuisance than a life threatening incident, and you're knocking out 10k rounds a month, you'd be foolish to replace them at 10k rounds.  

My statistics are made up, but I think it's fair to say the farther you get in round count, the more likely it is one of your parts will fail.  10k is a conservative, easy to remember replacement schedule.  Maybe the actual optimal number mathematically is 12,842 rounds.  Nobody's going to remember that.  A bolt costs $50, the extra 2,842 rounds of ammo itself costs probably $900.  The 10,000 rounds you shoot between each bolt costs probably $3000.  Unless you're not concerned with the consequences of a bolt failure, just buck up and spend the $50.  

Granted, maybe that's originally where the bolt life discussion started, and now it's morphed into people thinking they all fail on round 10,001.  That is clearly false.  It's also possible that the military found that 20,000 was the right number, and a few civilians decided they wanted a 2.0 factor of safety on that estimate.  Further muddling the waters is that the civilian market has varying qualities of bolts, so it makes sense that there'd be a different estimate for someone who's using all colt MPI/HPT bolts vs someone using whatever is in the latest $600 commercial AR.

TLDR:  A commercial shooting range can look at the average bolt life and base their replacement schedule on that.  Someone betting their life on a single specimen needs to look at the worst case scenario (within reason) for bolt life and base their replacement schedule on that.

Ron, this thread is epic...I keep coming back to it, and keep being impressed.  Thank you for sharing your experience with us...it's especially been helpful for someone like me, who doesn't have the money for Colt this and Colt that, but still wants something that will work and that I can feel good about.  Hearing that other companies do actually make products that hold up to similar/same usage patterns as Colt (like PSA, for one) has helped me feel comfortable about getting in the AR game for what I can afford and feel like I'm not throwing my money away.  Very much appreciated, sir!

 


 Colt isn't your high end AR's . Id say mid tier. You cab spend a whole lot more on other brands than Colt .    I think you should be safe with PSA . The Problems that most people have with  PSA , they took the rifles back and replaced  / corrected them.  Have Just got a PSA rifle and it has tolerance issues. Bolt  / carrier machined out of spec. PSA said they will take care of me. If your with in driving distances just go to one of there stores and hand pick and inspect before you buy. I think ones in SC and maybe in GA  now.   You need an AR . Merry Christmas  WarDawg


  P.S.  I  just noticed you are in Oregon....The dive might be a little long... Hey road trip !!!!!!

disagree on Colt and especially mid tier, not even sure how you can say that with a straight face and especially since your first qualifier was price.  Not the forum for the comparison so if you'd like, let's bring it to the forum and have a nice discussion

Merry Christmas everyone  :)

Ron, I visited your range a couple of weeks ago, it was great, Andrew (?) could not have done better.  I forgot to shoot the wolf piston upper, guess I need to go back.  Does it use a regular M16 bolt?

Thanks again, thought I might drag this excellent thread back on topic.

Gary what the heck have you been drinking .It it's Maker mark I'll have some . He posted Colt's cost vs other makes. There are several makes that are priced way above Colt . Colt would be Mid tier in cost comparison for complete rifles.I don't know why you think Colt is bottom tier.  PSA makes good AR's . PSA has been very good on anything wrong. Thanks for the Christmas card,  and Merry Christmas  .

Road trip for ARs!  Best road trip ever!  Thanks WarDawg...definitely more expensive out there, but even Colt pricing is out of my budget...right now ;-)

PSA FN uppers, PSA BCGs, and BA QPQ barrels for right now.  BCM and Colt down the road!

Very informative thread it has kept me busy reading during this slow week at work.

Thanks Ron, your place will be one I will make sure to visit if I go to Vegas.

Ron, How do HK weapons hold up on your range, specifically the roller locked 90's series variants but also their pistols, i havent had time to dig through the entire thread.