PSA 9MM UPPER

[TMD]

So how do you finish that thing? I've got an SBRd lower sitting around, but I don't want to cram a mag block in the lower with a hammer, I'd like something I can switch back and forth.

Like sig said, there are drop in (or drop up) mag blocks. The bottom insert mag blocks from hahn, spikes and others are kept in place by set screws and are easily removable. They also provide bho. Top inserts do not. I run the spikes without issues.

The biggest issue is that not all ar15 hammers work in a 9mm. My blackout has a giessele trigger/hammer. Won't work with the 9mm. That for me was enough reason to get a second (and soon third) sbr.

The hammer problem stems from the bolt carrier used. If your bolt is ramped then any standard hammer will work. Non ramped cut bolt carrier needs a notched hammer.

[Sithlord]

So how do you finish that thing? I've got an SBRd lower sitting around, but I don't want to cram a mag block in the lower with a hammer, I'd like something I can switch back and forth.

Like sig said, there are drop in (or drop up) mag blocks. The bottom insert mag blocks from hahn, spikes and others are kept in place by set screws and are easily removable. They also provide bho. Top inserts do not. I run the spikes without issues.

The biggest issue is that not all ar15 hammers work in a 9mm. My blackout has a giessele trigger/hammer. Won't work with the 9mm. That for me was enough reason to get a second (and soon third) sbr.

The hammer problem stems from the bolt carrier used. If your bolt is ramped then any standard hammer will work. Non ramped cut bolt carrier needs a notched hammer.

My bolt carrier IS ramped. The Geissele SD3G hammer (and many other Geissele hammers) simply do not work - they are not 'standard'. As I understand it, the hammer rides on the bolt carrier and never resets the disconnect spring.

It resets when manually pulling the charging handle. But WILL NOT reset when firing. I've also tried a CMMG drop in FCG (the one that came with the slide fire). It DID NOT WORK. But, throw in an ALG ACT, no issues, runs like a swiss watch.

[TMD]

Good to know. I've tried mine with a standard cheapo mil spec, a RRA two stage and a POF. Worked with all three. I have heard before more than once that the Geissele don't like them.

[A-Game]

I went ahead and grabbed one!! I'm going to go with the Colt mags, and bought the mag block that they sell as well.

I'm going to preface this with "I do not own a Glock"

With the prevalence of 33 round Glock mags I thought you would have gone that route instead of Colt.

Is there something I'm missing about Colt Mags vs Glock?

[VENT625]

I went ahead and grabbed one!! I'm going to go with the Colt mags, and bought the mag block that they sell as well.

I'm going to preface this with "I do not own a Glock"

With the prevalence of 33 round Glock mags I thought you would have gone that route instead of Colt.

Is there something I'm missing about Colt Mags vs Glock?

No preference at all. They sold the Colt block as well as the upper, thought making one purchase would be easier. I'll see how they work out.

[mbogo]

I ordered one of those last week. PSA is always slow to ship and uses slow shipping methods, so I still don't have it.

I ordered an RRA 9mm buffer, a Pro-Mag magwell block, and some Uzi 32rd. steel mags. I am going to run it with a dedicated, Slide-fire equipped lower

If I can locate a 1/2-36 piston for my Osprey, I'll install that as well for some real fun.

mbogo

[golfindia]

I went ahead and grabbed one!! I'm going to go with the Colt mags, and bought the mag block that they sell as well.

I'm going to preface this with "I do not own a Glock"

With the prevalence of 33 round Glock mags I thought you would have gone that route instead of Colt.

Is there something I'm missing about Colt Mags vs Glock?

You have to cut a relief in the bolt carrier to clear the glock ejector. Has anyone done this themself? I know ADCO and others perfrm this service, but it looks like it wouldn't be too tough to do at home on a mill.......

Several places are now offering 80% glock mag lowers, if I could figure out how to do a bolt i already have it would be a cool project.

9mm ARs are a blast to shoot.....

[VENT625]

I ordered one of those last week. PSA is always slow to ship and uses slow shipping methods, so I still don't have it.

I ordered an RRA 9mm buffer, a Pro-Mag magwell block, and some Uzi 32rd. steel mags. I am going to run it with a dedicated, Slide-fire equipped lower

If I can locate a 1/2-36 piston for my Osprey, I'll install that as well for some real fun.

mbogo

Yeah I ordered an upper (blem) earlier this year, took about 2+ weeks if I remember right. I'm not in a hurry.

[Sithlord]

I went ahead and grabbed one!! I'm going to go with the Colt mags, and bought the mag block that they sell as well.

I'm going to preface this with "I do not own a Glock"

With the prevalence of 33 round Glock mags I thought you would have gone that route instead of Colt.

Is there something I'm missing about Colt Mags vs Glock?

Colt pattern mags cost less. If you aren't worried about sharing or compatibility then it's a great reason. I also don't recall if bho is an option with glock mags in an ar.

[RDA]

I went ahead and grabbed one!! I'm going to go with the Colt mags, and bought the mag block that they sell as well.

I'm going to preface this with "I do not own a Glock"

With the prevalence of 33 round Glock mags I thought you would have gone that route instead of Colt.

Is there something I'm missing about Colt Mags vs Glock?

Colt pattern mags cost less. If you aren't worried about sharing or compatibility then it's a great reason. I also don't recall if bho is an option with glock mags in an ar.

You can get BHO with the Quarter Circle lower in Glock configuration. I went the Glock route for compatibility, I have lots of Glock mags and no Colt mags.