So what does Mil-Spec mean???

[Rider79]

PRVI is just fine.


If the bolt has a 5 coil spring in it, then no need for the o-ring.


C4

No need, as in it would just be overkill, or no need, as in it would cause problems?

[Caeser25]

The terms get over-used in all kinds of discussions. I was recently participating in a discussion on another forum about the function of 9mm AR magazines and one guy mentioned that the mags will work fine in a "milspec upper and lower". AFAIK there is no such thing when referring to the 9mm AR.

I was reading that one as well but don't post there so I couldn't reply.

[Gentoo]

I was reading the thread on TOS that prompted this bump a few things came up.

One was the idea that the controlling TDP spec was designed 40+ years ago, and current technology enables us to produce items that are not technically in the spec, but are superior. Is there any merit to this assertion? I would assume that the .gov would keep abreast of changes and modify the TDP accordingly, but I have no idea. This leads into the next point:

Another was that you can be in violation of the mil-spec yet produce a superior part. The implication was that if the spec called for material X and you used material Y, which was superior to material X, you would technically not be considered mil-spec, but the product would be better. This leads to some confusion as to what the specs mean - are the specific or minimum? In other words do they define a minimal level that must be obtained (i.e. at steel at least as good as 4150, but better is OK) or specific (only 4150 steel is acceptable).

The notion that MP testing only identifies surface defects was mentioned. I'm not sure I understand how this matters - a defect caught is a defect caught regardless. But suppose that is true, is there a way to check and see if there are subsurface defects?

Hope this makes sense... I've been up all night and am starting to crash but these thoughts are bouncing around in my head and I wanted to get them out.

[rob_s]

I was reading the thread on TOS that prompted this bump a few things came up.

One was the idea that the controlling TDP spec was designed 40+ years ago, and current technology enables us to produce items that are not technically in the spec, but are superior. Is there any merit to this assertion? I would assume that the .gov would keep abreast of changes and modify the TDP accordingly, but I have no idea. This leads into the next point:

Another was that you can be in violation of the mil-spec yet produce a superior part. The implication was that if the spec called for material X and you used material Y, which was superior to material X, you would technically not be considered mil-spec, but the product would be better. This leads to some confusion as to what the specs mean - are the specific or minimum? In other words do they define a minimal level that must be obtained (i.e. at steel at least as good as 4150, but better is OK) or specific (only 4150 steel is acceptable).

The notion that MP testing only identifies surface defects was mentioned. I'm not sure I understand how this matters - a defect caught is a defect caught regardless. But suppose that is true, is there a way to check and see if there are subsurface defects?

Hope this makes sense... I've been up all night and am starting to crash but these thoughts are bouncing around in my head and I wanted to get them out.

re-read my post re: building codes.

Better isn't better unless you can prove it.

[C4IGrant]

I was reading the thread on TOS that prompted this bump a few things came up.

One was the idea that the controlling TDP spec was designed 40+ years ago, and current technology enables us to produce items that are not technically in the spec, but are superior. Is there any merit to this assertion? I would assume that the .gov would keep abreast of changes and modify the TDP accordingly, but I have no idea. This leads into the next point:

The TDP is an evolving document and the Govt does in fact make changes to it. There are much better ways to make bolts (like the KAC IWS system for instance), but there are only a handfull of companies (maybe just one) have have actually improved the bolt.

Buying BCG's from .Mil part suppliers means that you get parts that will generally meet the TDP specs. What people fail to realize is that they parts cannot be above the mil-standard!

Another was that you can be in violation of the mil-spec yet produce a superior part. The implication was that if the spec called for material X and you used material Y, which was superior to material X, you would technically not be considered mil-spec, but the product would be better. This leads to some confusion as to what the specs mean - are the specific or minimum? In other words do they define a minimal level that must be obtained (i.e. at steel at least as good as 4150, but better is OK) or specific (only 4150 steel is acceptable).

Yes. You can ask for a waiver if you are offering a product that is above what the Govt calls for. So yes, technically you did not follow the TDP, but you have shown the Govt. they can have a better product for the same money.

The TDP is specific in its requirements. I would also view the mil-standard to be the MINIMUM allowable spec to be used (and work).

4150 steel does NOT meet the TDP specs (FYI). Only 4150-ORD, 4150-Sulp. and CMV meet the standard.

The notion that MP testing only identifies surface defects was mentioned. I'm not sure I understand how this matters - a defect caught is a defect caught regardless. But suppose that is true, is there a way to check and see if there are subsurface defects?

You are correct. A defect is a defect. Caught is caught and it is ALWAYS better to catch them than not catch them.

The only way to check inside the bolt is via XRAY. This is a better way to do it than HP/MP, but I do not believe that anyone does it.

Hope this makes sense... I've been up all night and am starting to crash but these thoughts are bouncing around in my head and I wanted to get them out.

Your post does make sense and hope that my answers help you.


C4

[AMMOTECH]

Currently, I am told that each and every bolt/barrel needs to be HP and MP'd.



C4

FN does every bolt and barrel. They get proofed then MPI.

.

[Yojimbo]

Another reason I prefer "Mil-Spec" or parts manufactured to the "TDP" standards is because at the very least you know it was made to some type of standards.

This doesn't mean things can't be "just as good as" but if the part is made to unknown standards or no standardsn then how do you really know?

I completely understand and know that that a part made to the "TDP" standards can still fail but I find comfort in knowing some type of QC has been used to help avoid premature failure.

It really bugs me when folks claim that their parts are "just as good as" but yet the part they're talking about hasn't even gone through the same QC as the part they claim it to be "just as good as"...

[C4IGrant]

Another reason I prefer "Mil-Spec" or parts manufactured to the "TDP" standards is because at the very least you know it was made to some type of standards.

This doesn't mean things can't be "just as good as" but if the part is made to unknown standards or no standardsn then how do you really know?

I completely understand and know that that a part made to the "TDP" standards can still fail but I find comfort in knowing some type of QC has been used to help avoid premature failure.

It really bugs me when folks claim that their parts are "just as good as" but yet the part they're talking about hasn't even gone through the same QC as the part they claim it to be "just as good as"...

Right you are! What should piss people off even more is when they are paying the EXACT same amount, but not getting the same level of quality.


C4