"Beware the Rats of MIM."

[chead]

Hollow cast? Wow. That's pathetic.

Seriously, that's terrible.

[milotrain]

RRA with national match trigger $130
RRA with single stage trigger $68

Working the price on an LPK is bleeding the stone. You spend an inordinate amount of your own time figuring out a way to save $9.99

[wash]

As far as I know, there is no way to "hollow cast" things like that.

You wouldn't do it intentionally any way.

A simple QC check for that would be to weigh parts and reject parts that are light.

I've never had a problem with DPMS except for crummy trigger pull but that's a sample size of about 3...

[Pete1979]

Same thing happened to the slide stop on my Springfield 1911 about two weeks ago, just a defective part. The only problem is on the AR. that roll pin is a PITA to work with...

[Sonic_mike]

does the stag lpk have any mim parts?

[MrExel17]

Good to know thanks for the info!

[Steelheader]

Same thing happened to the slide stop on my Springfield 1911 about two weeks ago, just a defective part. The only problem is on the AR. that roll pin is a PITA to work with...

That's why I ordered one of these:

Bolt Catch Pin Punch

[wash]

You'll notice the bolt hold open did not break at the roll pin hole.

This is clearly a manufacturing defect rather than a design issue.

And if you have a T25 security TORX bit and a magnetic tip screwdriver handle, you can do exactly what a special roll pin starter punch would do. It's cheaper and you can find it at the local hardware store too.

[arsilva32]

hey i like that Bolt Catch Pin Punch, i'm always worried that i'll slip and scratch the krap out of my receiver.

[Steelheader]

hey i like that Bolt Catch Pin Punch, i'm always worried that i'll slip and scratch the krap out of my receiver.

That's why I bought one. I used to use the needlenose vise grip method, but no matter how well I taped the jaws, they always would mar the pin housing. With the tool and a quality non-marring hammer, I'm GTG.

[joefrank64k]

As far as I know, there is no way to "hollow cast" things like that.

You wouldn't do it intentionally any way.

A simple QC check for that would be to weigh parts and reject parts that are light.

I've never had a problem with DPMS except for crummy trigger pull but that's a sample size of about 3...

Agreed...that's a QC issue for sure, not some intrinsic problem with MIM. The metal powder didn't fill the mold all the way before it was fired. Like you said, weighing the parts would spot that defect easily. MIM allows for amazingly complex small parts that can be sold for less than machined. As long as QC is followed, MIM parts are fine.

[lelandEOD]

It's not hollow, just a bubble like someone pointed out. Just poor QC.