MPI Tested

[Neeglik]

Did a search and couldn't find any info on MPI tested bolts and barrels, sooooo...

What is it?

What does it do??

Do I want it???

Thanks!

[TacDoc]

All I know: its good and LMT does it, yes you want it. Probably someone here may ilustrate the tech details about MPI.

[clynch]

MPI stands for Magnetic Particle Inspection. It is a type of NDT process (Non-Destructive Testing) to check for flaws, cracks, etc in metal/conductive parts.

Basically, the part to be inspected is magnetized, and exposed to magnetic particles (either suspended in air or liquid), which are attracted to any cracks or fishures in the part. Any "reading" (high concentration of particle attraction) beyond nominal or acceptable limits and the part is usually disposed of. This may sound sort of vague, due to the fact that different parts have different acceptable standards, and different companies have different criteria for acceptance.

For example, there are small cracks that form at the base of the lugs on an M16 bolt after it is proof fired. The degree and location of these cracks is compared to the government inspection standard / quality assurance provision, which in turn determines whether the part is acceptable. Assuming the part is correctly proofed and then final-finished (phosphate), it is marked "MPI" to signify acceptance.

Hope this helps,
Clint

[C4IGrant]

It is something you want in both your barrel and your bolts. To my knowledge, LMT, Colt and special ordered CMT (Stag Arms) are MPI tested.

For barrels, LMT, Colt and BCM are HPT and MPI tested. There maybe others, but I can't think of any.

The thing to be careful of is that some companies MPI a couple barrels out of a batch, but go ahead and mark every barrel as being MPI tested (bad juju in my book).

The other big burning question is what are these companies exit criteria for a flawed barrel or bolt? I think some companies allow minor flaws in their products.

The only company I can say for sure that has a zero flaw acceptance policy is BCM.



C4

[Leaveammoforme]

MPI stands for Magnetic Particle Inspection. It is a type of NDT process (Non-Destructive Testing) to check for flaws, cracks, etc in metal/conductive parts.

Basically, the part to be inspected is magnetized, and exposed to magnetic particles (either suspended in air or liquid), which are attracted to any cracks or fishures in the part. Any "reading" (high concentration of particle attraction) beyond nominal or acceptable limits and the part is usually disposed of. This may sound sort of vague, due to the fact that different parts have different acceptable standards, and different companies have different criteria for acceptance.

For example, there are small cracks that form at the base of the lugs on an M16 bolt after it is proof fired. The degree and location of these cracks is compared to the government inspection standard / quality assurance provision, which in turn determines whether the part is acceptable. Assuming the part is correctly proofed and then final-finished (phosphate), it is marked "MPI" to signify acceptance.

Hope this helps,
Clint

Interesting.

I win by the way.

[Ryno12]

I win by the way.

For the necropost of the century?

[GH41]

For the necropost of the century?

I agree but if he didn't do it IG would have canned the thread!

[Iraqgunz]

Pretty much. Or at a minimum the decade.

For the necropost of the century?

[strambo]

I can't keep up with who does what, we need a chart!

[samuse]

You can MPI any ferritic metal anytime you want. I've been MPI certified since 1998. I should start an MPI service for M4C.

I would even do a liquid penetrant for no extra charge!