What is MilSpec - and should I care...

Leg said:
Are you on glue? Just think about that for a second.

Not all commercial tubes are slanted on the end either. Carbines did exist prior to the slanted M4 style buttstocks being introduced around 2002.

Mirk brings up a good point. Just because a tube is mil-spec diameter doesn't mean that it meets the rest of the specs laid out in the TDP.
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This is what I was referring too.

milspecthread-1.png


Is that accurate? I'm not 100% certain and would be quite happy to see it confirmed.

Good job on the smarta$$ comment; it's what makes this place great :rolleyes:
 
OK, I don't understand why the commercial tubes would have to be smaller OD. If the threads don't fully meet, what is the point of making a tube like that? Also, what is the reason for the slanted end on the commercial tube? Is it related to the extrusion process?

From what I understand, the mil-spec tubes are forged and bored as opposed to the commercial extrusions. However, some mil-spec tubes, such as made by VLTOR, are also extruded, so even though they have the proper OD, they are also not as strong as the forged tubes.
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The spec says 'hammer extruded' which means it can be traditionally 'stamped' in a die, or it can be extruded in an extruding machine (think play-doh fun factory).

Both types are solid as a raw blank and then get drilled out. It would be more labour intensive to weld an end cap on and then machine it to 'hide' it.

The reason that commercial generally have 'smaller' threads is because they are extruded (forged) to 1.17" the full length. So then they just turn or roll-form the thread and it's essentially a 'topped' thread.
With mil-spec, either they extrude (forge) the tubes to at least 1.1875" right off the bat and only machine down the back end with a special cutter, or they extrude them to 1.17" and roll-form the threads on (acceptable) which would push that section back up to 1.1875"

so even though they have the proper OD, they are also not as strong as the forged tubes.
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They are just as strong. Whether stamped in a die or pushed through an extruding die, both are acceptable as 'forged'



What I want to know is; is anyone measuring the minor diameter in their 'mil-spec' lowers to make sure it's not oversize? That affects thread engagement too.


Bottom line is that if you break your buffer tube, regardless of the type, you were doing something with it that you weren't supposed to be doing with it.
 
notsorichguy said:
Commercial tubes have a larger OD than mil spec tubes. Ever try to put a mil spec stock on a commercial tube...... It doesn't.
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Since we're discussing tubes, I really like the PWS tubes. The one-piece design eliminates the need for a castle nut, and it has a unique retainer plate that ensures it aligns properly and is locked completely in-place with a bolt. They have two integrated QD sling mounts, an extended bottom lip to reduce carrier tilt, a dead-blow feature to reduce felt recoil and is fluted to allow debris to be pushed out. It also has a drainage hole. A bit more expensive than a standard tube, but well worth the money IMHO. This is probably another example of where it isn't necessarily "mil-spec" and probably exceeds it.
 
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Is that accurate? I'm not 100% certain and would be quite happy to see it confirmed.
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Sort of, except for the part where the tube is thinner at the root of the thread. The threads will be cut/formed no deeper on the commercial than the mil-spec but the commercial threads will be 'topped' whereas the mil-spec are full profile.
 
*MALICE* said:
Sort of, except for the part where the tube is thinner at the root of the thread. The threads will be cut/formed no deeper on the commercial than the mil-spec but the commercial threads will be 'topped' whereas the mil-spec are full profile.
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Thanks for the additional info Malice.

Good thing it was just regular wood glue and not contact ciment ;)
 
Also, what is the reason for the slanted end on the commercial tube? Is it related to the extrusion process?
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This has nothing to do with the extrusion process. I believe (and I'm not 100% on this particular aspect) it's to match current production stocks that have a slanted back, as I think once upon a time the 'standard' stocks had a flat back which matched the mil-spec tubes.

Good thing it was just regular wood glue and not contact ciment
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Mixing both is fun for a boring Friday night ;)
 
In case anyone ever wondered, this is along the lines of the cutter used to cut the profile on mil-spec tubes that is not done on commercial tubes

images
 
300Spartans said:
OK, I don't understand why the commercial tubes would have to be smaller OD. If the threads don't fully meet, what is the point of making a tube like that? Also, what is the reason for the slanted end on the commercial tube? Is it related to the extrusion process?
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Not all Commercial tubes are slanted
- re the threading aspect: threading that way is cheaper and faster.

From what I understand, the mil-spec tubes are forged and bored as opposed to the commercial extrusions. However, some mil-spec tubes, such as made by VLTOR, are also extruded, so even though they have the proper OD, they are also not as strong as the forged tubes.
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They are solid impact extrusions that are bored. The bottom "pocket" should not have right angle cuts either, as this reduce the chance of cracking.

Some commercial tubes are hollow extrusions that are threaded/capped however.

The gist of what I am trying to point out on this is that their is no Standard for a non MilSpec item. The result of this is that an item can then either be above or below that Standard.
 
The gist of what I am trying to point out on this is that their is no Standard for a non MilSpec item. The result of this is that an item can then either be above or below that Standard.
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This is correct.

Some commercial tubes are hollow extrusions that are threaded/capped however.
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I still think this is a myth.
 
blaxsun said:
Since we're discussing tubes, I really like the PWS tubes. The one-piece design eliminates the need for a castle nut, and it has a unique retainer plate that ensures it aligns properly and is locked completely in-place with a bolt. They have two integrated QD sling mounts, an extended bottom lip to reduce carrier tilt, a dead-blow feature to reduce felt recoil and is fluted to allow debris to be pushed out. It also has a drainage hole. A bit more expensive than a standard tube, but well worth the money IMHO.
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Yeah, it's a minor PITA aligning a regular buffer tube so that it's straight, which the PWS stock eliminates. I have been tempted to create some kind of jig for aligning buffer tubes.
 
Ah Ha!
So KAC is not Mil-Spec...
Damm I baught a bag of bolts then?
Can it shoot 556 fine if it's maked 223?
 
And to push the hair-splitting some more, PWS also produces a MilSpec buffer tube that is CNC machined out of a solid billet of 7025 and not extruded or else. It's Hk416 Enhanced Buffer tube and runs about 2x the cost of their enhanced MilSpec model.
 
The sad part is that MILSPEC always = more money, but it does not always = better quality. A lot of companies will throw MILSPEC on their products because they meet the requirements of the actual MILSPEC in dimension and possibly finish, but they don't meet the manufacturing or testing requirements to actually be MILSPEC. In the commercial world it has simply become a marketing term to attract those who truly believe their #### will fall off if they don't use it.

Not to say you shouldn't seek out the best quality parts, but be sure you aren't being lured in by a word that may or may not indicate a better quality product.
 
Allen Gun Works said:
The sad part is that MILSPEC always = more money, but it does not always = better quality. A lot of companies will throw MILSPEC on their products because they meet the requirements of the actual MILSPEC in dimension and possibly finish, but they don't meet the manufacturing or testing requirements to actually be MILSPEC. In the commercial world it has simply become a marketing term to attract those who truly believe their #### will fall off if they don't use it.
Not to say you shouldn't seek out the best quality parts, but be sure you aren't being lured in by a word that may or may not indicate a better quality product.
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And this is exactly the point that many people often miss when discussing the term. The term MILSPEC has become almost meaningless because of the way it's been misused in recent years. Unfortunately too many times the term has been used by manufacturers and retailers to describe a product that is made to meet the "dimensional" standards setout by the MILSPEC but all too often those products do NOT meet the "material" standards required by the MILSPEC... nor do they usually meet the "testing" standards setout by the MILSPEC... and therefore the end result is NOT true MILSPEC.

If the material is of inferior quality, it really doesn't matter that the dimensions meet MILSPEC... you can have "junk" that is made to MILSPEC dimensions... it's still junk :(. Using lesser quality materials and eliminating or reducing testing protocols will allow a manufacturer to save money and sell cheaper... but it also produces a cheaper quality product. It is important to know exactly what a manufacturer means when they use the term "MILSPEC" in their advertising.

KAC produces MILSPEC products... the dimensions are correct... materials are correct... testing protocols are known to them (because of their military contracts) and they perform those tests. When Knights says that an item meets or exceeds the MILSPEC then you can be assured that it does (in all 3 areas: Dimension/Material/Testing). There are other companies that also produce MILSPEC product... but there are many companies that use the term MILSPEC but only actually refer to dimensional characteristics... little or no effort is actually made to comply with material specifications and/or testing criteria.

At least this is what I've seen over the years.

KevinB has more experience with this on a day to day basis than I do.

Having said this, if a product is made to correct dimensions and made from high quality materials (which at times can exceed an old or outdated MILSPEC), and if testing protocols are sufficient to insure reliability and quality... then it is quite possible to produce an item that is is not MILSPEC but is in fact superior. Just because something isn't MILSPEC doesn't mean it is not acceptable or even better.

I'm sure KevinB can confirm that KAC has developed a number of very high quality products that are NOT technically MILSPEC but are in fact better in many ways than the MILSPEC items they were designed and built to replace and/or compete against. There are other companies that also offer such non-MILSPEC items.

The first step is understanding the difference between "marketing-MILSPEC" claims and "military-MILSPEC" claims and knowing which one is being used to describe an item... that can often be difficult to find out.

Mark
 
Thanks for expanding on my point.

For anyone who doesn't understand the term, just google M4 or M16 MILSPEC and read one of the many documents that is floating around the interweb. Once you finish reading it, after falling asleep a couple of times, you will understand what is involved.
 
BenL said:
This is what I was referring too.



Is that accurate? I'm not 100% certain and would be quite happy to see it confirmed.

Good job on the smarta$$ comment; it's what makes this place great :rolleyes:
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You said that the thread pattern was different, which they are not, both are threaded 1-3/16"-16 tpi.

This post clarifies what you were referring to, but your original post was very misleading. You can think I'm an ass all you want but the first post was filled with misleading and incorrect info, something that happens all too often around here.

I do believe that mil-spec receiver extensions have only been made as 2 and 4 position, yet most aftermarket tubes regardless of manufacturing standards have 5 or 6. Can they truly be called mil-spec. A lot would argue that more positions are better, and I certainly can't argue with that, but it still strays from the TDP.
 
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