Mil spec

[ugaarguy]

However, by that line of thinking, couldn't one up the ante with stronger barrel extension, or lessen the hardness of either bolt or extension?

Potentially, but it is worth the added R&D, the added steel cost, the accelerated wear on tooling to make such parts? The current bolts (C158 steel, properly heat treated, shot peened to relieve strees, and that pass the HPT / MPI) average over 10k rounds before failure. Considering that the M16 family of rifles have been thoroughly refined over their 51 years in service, I'm pretty confident that they've found the point of diminishing returns on bolt material and manufacturing process.

As you and several others have noted, the key is identifying the most critical or significant specs of the rifle.

 

[meanmrmustard]

Potentially, but it is worth the added R&D, the added steel cost, the accelerated wear on tooling to make such parts? The current bolts (C158 steel, properly heat treated, shot peened to relieve strees, and that pass the HPT / MPI) average over 10k rounds before failure. Considering that the M16 family of rifles have been thoroughly refined over their 51 years in service, I'm pretty confident that they've found the point of diminishing returns on bolt material and manufacturing process.

As you and several others have noted, the key is identifying the most critical or significant specs of the rifle.

If Joe Average had the money...maybe.

I don't, but I recognize quality and where I need meat and potatoes or where I can skimp.

Hence how I voted. Thank you for the info UG

 

[hatt]

9310 has better wear resistance, but is costlier .
Harder, yes.

Do 158C bolts "wear" out in any reasonable service life? All the bad ones I've seen were broken. Looks like a harder bolt would be even more prone to breaking.

 

[meanmrmustard]

Do 158C bolts "wear" out in any reasonable service life? All the bad ones I've seen were broken. Looks like a harder bolt would be even more prone to breaking.

The same could be said of the 4150 CMV barrels, being harder and more brittle than 4140. However, seen either of those fail?

I haven't. Not a kaboom anyway, but anything can wear. Just some faster than others.

So, how would 9310 be more prone to breakage?

 

[hatt]

By "being harder and more brittle?" A bolt and barrel are vastly different apps.

 

[meanmrmustard]

By "being harder and more brittle?" A bolt and barrel are vastly different apps.

Indeed, but both see tremendous pressure, friction and heat. So, the apps are different, but the environment they perform them in is quite similar.

 

[hatt]

Don't know how you're comparing a steel tube to a small complex machined moving part.

 

[ugaarguy]

Go back to what Hatt is saying. The bolt is bearing all that pressure on its face and the seven lugs. The bbl is bearing that same pressure across a much larger surface that's also uniform. Hence, brittleness in bolts is much more of a problem than brittleness in barrels. There's also the issue of the bbl needing to be of a proper alloy and heat treat to maintain the rifling. Keep in mind also that a SAW bbl is a totally different bbl from an M16 bbl.

 

[Slamfire]

I was active duty from 1985 to 2005, and yes I was a Nuke. So I'm a little familiar with the process, though one of my collateral duties was NOT as repair parts petty officer for my division.

I agree that "milspec" is an abused term. Typically rendered as "mil-(letter designation)-XXXXX", or the newer "MSXXXXX" format. Like "MS51958" is the milspec for "screw, machine pan-head, cross-recessed, corrosion-resisting steel, UNF-2A".

Hey, Chief, thanks for your service to our country. Submariner was an elite group and not a job I could have done as I would have gone nut case without a window!

Since you left life has gotten harder for all Government agencies in procuring good hardware. Smart people have created briefings predicting the end of all manufacturing in the US. Getting good bolts, nuts, screws is just one of these issues. The vast, if not all, is coming now from China. People in the loop tell me the fasteners are inferior to what you used to get from American vendors. The certifications that come with the fasteners are not worth the paper they are printed on. You can’t buy an electronic part that does not have Chinese components.

How will people feel when a product made 100% in China is labeled "Mil Spec"?

 

[meanmrmustard]

Go back to what Hatt is saying. The bolt is bearing all that pressure on its face and the seven lugs. The bbl is bearing that same pressure across a much larger surface that's also uniform. Hence, brittleness in bolts is much more of a problem than brittleness in barrels. There's also the issue of the bbl needing to be of a proper alloy and heat treat to maintain the rifling. Keep in mind also that a SAW bbl is a totally different bbl from an M16 bbl.

Doesn't the SAW operate at 850+ rounds a minute though?

 

[Mike1234567]

It has not been my experience that the government does not know what's in the TDP. While the government may not have developed it, they know what's in it because if the contractor does not deliver what was promised, that's one of the things the government will be scrutinizing to see if the TDP (among other documents) was followed. On the contracts I worked on, there were government inspectors onsite to ensure the government was getting what they were paying for. You may be selling them $600 toilet seats, but if it doesn't meet the specs or if proper procedures are not followed or the promised number are not delivered on time, they will fine you and yank the contract and give it to somebody else

You assume the government employees watching/policing incoming products know what they're doing or even care. I was civil service for nearly a quarter century and can assure you... that ain't always the case.

Specifying a very specific product that is only made by ONE manufacturer is nearly always a sign of palm-greasing behind back doors.

 

[ugaarguy]

Doesn't the SAW operate at 850+ rounds a minute though?

That's the cyclic rate, but the sustained rate is much lower. The point I was trying to make though is that a LMG bbl is an entirely different animal from a rifle bbl. The M249 (and most true machine guns) have quick change bbls to start with. When the bbl gets hot you swap to the spare and let the first bbl cool. Belt fed MGs don't have the accuracy requirements of rifles, and indeed rifle level accuracy is undesirable in a MG. Hence, with a MG bbl your priority is not precision. Your priorities are getting the most endurance for the lowest price. Even so, MG bbls get shot out and require replacement much more frequently than rifle bbls.

 

[hatt]

A bolt from different material may indeed be better. But that doesn't do me any good if I don't know how much better. I know kinda what to expect from a milspec bolt because of decades and billions of rounds fired and can plan accordingly. It also may not be as good. This is all academic, 99% of people are never going to shoot enought to wear out an AR. If you run your gun hard and depend on it in life and death situations replace the bolt/springs/etc every 5-7000 rounds and worry about other stuff.

 

[Warp]

A bolt from different material may indeed be better. But that doesn't do me any good if I don't know how much better. I know kinda what to expect from a milspec bolt because of decades and billions of rounds fired and can plan accordingly. It also may not be as good. This is all academic, 99% of people are never going to shoot enought to wear out an AR. If you run your gun hard and depend on it in life and death situations replace the bolt/springs/etc every 5-7000 rounds and worry about other stuff.

It also doesn't do any good if you don't know which other material may be better...and that "may be" means that it may not be.

We've gone full circle. The 'mil spec' is a known quantity that is pretty darn good.

 

[meanmrmustard]

It also doesn't do any good if you don't know which other material may be better...and that "may be" means that it may not be.

We've gone full circle. The 'mil spec' is a known quantity that is pretty darn good.

What's to say he doesn't know? The statement nay be general.

Good enough, better than good, and "pretty darn good" are also subjective.

I love polls!!!

 

[Warp]

What's to say he doesn't know? The statement nay be general.

Good enough, better than good, and "pretty darn good" are also subjective.

I love polls!!!

Would you please be so kind as to tell us what the best is, and why?

 

[meanmrmustard]

Would you please be so kind as to tell us what the best is, and why?

I know what works for me, but not you.

I don't pretend to know everything, but I dont try to convince myself or anyone else here with subjective statements.

If mil spec works for you, super. As of now, more folks polled could care less. Me too.

 

[Warp]

I know what works for me, but not you.

I don't pretend to know everything, but I dont try to convince myself or anyone else here with subjective statements.

If mil spec works for you, super.

What works for you?

How well does it work for you?

Quantitatively stated.

 

[meanmrmustard]

What works for you?

How well does it work for you?

Quantitatively stated.

Thank you for asking.

For my HD gun, BCM. Haven't had to "use it" other than training. So far so good.

My plinker, 8620 S&W. Works well.

Longrange? Doesn't matter so long as it headspaces.

And you?

 

[Warp]

Thank you for asking.

For my HD gun, BCM. Haven't had to "use it" other than training. So far so good.

My plinker, 8620 S&W. Works well.

Longrange? Doesn't matter so long as it headspaces.

And you?

So...mil spec Carpenter 158 for the bolt?

 

[meanmrmustard]

So...mil spec Carpenter 158 for the bolt?

In my bedside rifle, yes.

Got it as a B-day gift.

 

[hatt]

LOL, all the arguing about better bolt material and he uses mil spec for the go to gun.

 

[meanmrmustard]

LOL, all the arguing about better bolt material and he uses mil spec for the go to gun.

Would it have mattered if it were in any of the others?

Did you know my "go to" gun doesn't have a forward assist or dust cover? Or that the barrel is 4140!!! Oh my gosh!

I may as well not even use it during a BandE. May fail.

 

[RetiredUSNChief]

Hey, Chief, thanks for your service to our country. Submariner was an elite group and not a job I could have done as I would have gone nut case without a window!

Since you left life has gotten harder for all Government agencies in procuring good hardware. Smart people have created briefings predicting the end of all manufacturing in the US. Getting good bolts, nuts, screws is just one of these issues. The vast, if not all, is coming now from China. People in the loop tell me the fasteners are inferior to what you used to get from American vendors. The certifications that come with the fasteners are not worth the paper they are printed on. You can’t buy an electronic part that does not have Chinese components.

How will people feel when a product made 100% in China is labeled "Mil Spec"?

Thanks for the recognition.

I've retired from active duty, however I still work for the Department of the Navy as a nuclear engineer at one of their shipyards. So I'm much more involved with materiall appropriation, milspecs, and engineering evaluation/planning than I was before.

An interesting aspect of the military that deals directly with your concern, which ultimately is inferior quality material and equipment, is the fact that such things ARE addressed through the processes already in place in the Navy...and I assume also in the other branches as well. High maintenance and repairs, as well as component defects and failure rates, are tracked for a huge fraction (if not ultimately all) parts, components, and equipment. Not just in the nuclear world, either. The system does factor these concerns in for improvements, alternate sources, design changes, and so forth.

Where the material is made doesn't matter, so long as it meets specifications and works as it should.

 

[MistWolf]

You assume the government employees watching/policing incoming products know what they're doing or even care. I was civil service for nearly a quarter century and can assure you... that ain't always the case.

Specifying a very specific product that is only made by ONE manufacturer is nearly always a sign of palm-greasing behind back doors.

The Air Force Colonel that oversaw the C-17 program was a stickler and knew his business. He knew what McDonnell-Douglas was supposed to be delivering.

On another contract, the guys that oversaw the maintenance we performed on helicopters for the Army may not have known how to do maintenance, but they knew what documents we needed to follow and what those documents said.

Neither situation was perfect, but those guys knew what documents we needed to follow and they knew what those documents say. When something went wrong, they knew how to follow the paper trail to determine if procedures were followed or not. The AR TDP covers more than just specifying what steel the barrel is to be made of