9mm mag block for 5.56 lower....which one?

[R L Suehr]

I would recommend Foxtrot Mike (FM Products) line of 9mm rifles and AR pistols. I am running one of their uppers on a PSA lower and it has been flawless. You can get a entire 9mm AR pistol setup from them on Primary Arms for $500 and I am sure the rifle would not be much more. Once you add in the cost of the mag block and complete 9mm upper, you can easily build an entire 9mm rifle. Not to mention, the forward charging handle is kinda cool too.

Is it the Glock or Colt lower? I have a PSA Glock mag lower and I really like the FM side chargers. I've been kicking around getting the 7 1/2" at tax time.

As others said, I considered the mag block too when I bought my lower. The stripped PSA was just as cheap as buying a decent mag block. Even with a transfer it was a push basically.

[Zeros]

Is it the Glock or Colt lower? I have a PSA Glock mag lower and I really like the FM side chargers. I've been kicking around getting the 7 1/2" at tax time.

As others said, I considered the mag block too when I bought my lower. The stripped PSA was just as cheap as buying a decent mag block. Even with a transfer it was a push basically.

I am using the PSA glock lower with my FM upper. I will say it is a tight fit because I think the PSA lower is a bit out of spec, but it works. When I put the FM upper on my PSA 223 upper, it is a perfect fit. I just have to push on the take down pins pretty hard to lock the upper into the PSA glock lower, but so far its been flawless. In hindsight, I should have spent the extra $50 to get the FM products billet 9mm lower, since I think its a bit nicer and LRBHO would have worked, but oh well. I am running the Taccom 3 stage buffer with the short stroke kit now, so that would have defeated the LRBHO anyways.

[R L Suehr]

I am using the PSA glock lower with my FM upper. I will say it is a tight fit because I think the PSA lower is a bit out of spec, but it works. When I put the FM upper on my PSA 223 upper, it is a perfect fit. I just have to push on the take down pins pretty hard to lock the upper into the PSA glock lower, but so far its been flawless. In hindsight, I should have spent the extra $50 to get the FM products billet 9mm lower, since I think its a bit nicer and LRBHO would have worked, but oh well. I am running the Taccom 3 stage buffer with the short stroke kit now, so that would have defeated the LRBHO anyways.

Awesome, thanks for the info.

[hunterdan]

I originally built my 9mm on a standard lower with a pro mag, Colt mag block. It functioned well, but to feed reliably, I had to close the bolt, put the mag in, and tap to seat. If I did it with the bolt open, the mag would go in too far and bolt would hit the mag. Not a huge deal, but a pain. A few weeks ago I picked up a dedicated cmmg 9mm Colt lower and put it together. I much prefer the dedicated lower, and the mag insertion issues are gone. The dedicated lower is cheaper than some of the better mag blocks and I really don't see me taking it apart to do something else with it. I really love shooting this gun and it's fun to plink with at the range.

[God's Country]

The more research I do the more confused I get.....lol

The cost is getting a bit out of control.

At first I thought a PSA upper, and I would be off. Now it looks like they're supposed to be used on their dedicated forged lowers. Not quite sure, but regardless it looks like their bolts aren't cut specifically to catch on the last round........true? I do want that.

So I started piecing my own upper parts, and the cost was getting pretty high. I believe the PSA was around $350. Can't remember the exact cost, but a stripped upper, Glock cut BCG, 16" barrel, and mid priced hand guard (similar to what is supplied on the PSA upper) was $450 plus.

By contrast I can go with a Stern defense kit for around $500 plus mag block. At least they should run good together, and may be better quality.

Then add in stock , buffer, and lower parts kit, maybe an enhanced trigger probably another $200-$250, and $180 for the mag block I'm pushing $900.

Crazy?

[Hodgie]

The more research I do the more confused I get.....lol

The cost is getting a bit out of control.

At first I thought a PSA upper, and I would be off. Now it looks like they're supposed to be used on their dedicated forged lowers. Not quite sure, but regardless it looks like their bolts aren't cut specifically to catch on the last round........true? I do want that.

So I started piecing my own upper parts, and the cost was getting pretty high. I believe the PSA was around $350. Can't remember the exact cost, but a stripped upper, Glock cut BCG, 16" barrel, and mid priced hand guard (similar to what is supplied on the PSA upper) was $450 plus.

By contrast I can go with a Stern defense kit for around $500 plus mag block. At least they should run good together, and may be better quality.

Then add in stock , buffer, and lower parts kit, maybe an enhanced trigger probably another $200-$250, and $180 for the mag block I'm pushing $900.

Crazy?

I went through the same exact thing about s year ago and then ended up buying a PAK-9 9 mm AK pistol and put a brace on it for half the price.

I still want a AR9 but at this point would just buy a complete PSA pistol for $550.00 and be done with it. I’m not using it for anything more then a range toy and if there’s an issue PSA will repair for life.

[God's Country]

I went through the same exact thing about s year ago and then ended up buying a PAK-9 9 mm AK pistol and put a brace on it for half the price.

I still want a AR9 but at this point would just buy a complete PSA pistol for $550.00 and be done with it. I’m not using it for anything more then a range toy and if there’s an issue PSA will repair for life.

I'm not into the pistols. Don't care for the short stock. They're fun, but I don't find them practical. The only way I would go that route would be an SBR, which defeats the purpose for me on this build.
I knew this wasn't the cheap way to go, and I'm not expecting cheap. One would think if I could drop $550 on a dedicated 9mm, I could throw one together for $700, and it would be flexible down the road.
Especially since I have the lower.

[ExFlyinguy]

The more research I do the more confused I get.....lol

The cost is getting a bit out of control.

At first I thought a PSA upper, and I would be off. Now it looks like they're supposed to be used on their dedicated forged lowers. Not quite sure, but regardless it looks like their bolts aren't cut specifically to catch on the last round........true? I do want that.

So I started piecing my own upper parts, and the cost was getting pretty high. I believe the PSA was around $350. Can't remember the exact cost, but a stripped upper, Glock cut BCG, 16" barrel, and mid priced hand guard (similar to what is supplied on the PSA upper) was $450 plus.

By contrast I can go with a Stern defense kit for around $500 plus mag block. At least they should run good together, and may be better quality.

Then add in stock , buffer, and lower parts kit, maybe an enhanced trigger probably another $200-$250, and $180 for the mag block I'm pushing $900.

Crazy?

I ran into this wanting to do a .22lr upper build. Already having a stripped upper laying around, I couldn't build a upper that I wanted for less than a M&P 15-22.

I've already got 4 complete guns and I don't want another. Just wanted a short barrel .22lr upper for giggles but too much $$

Ended up just grabbing a conversion bolt for now

[God's Country]

You guys aren't very good at talking me into this.

[hunterdan]

Check out Delta team tactical for uppers and bcgs. My original build was done for less than $550 using a mag block in a standard lower for Colt mags. So far, I've had decent luck with Delta team tactical. Some of their upper prices are amazing. I'm sure it's not too quality stuff, but for the guy who shoots once or twice a month or so, it works and I've not had any issues. I think I paid less than $190 for my assembled 9mm upper. Their shipping seems to be pretty quick and I haven't had any issues there either.
https://www.deltateamtactical.com/DT...CG_p_6049.html
Add a BCG and lower/block and you're in it for under $500

https://www.deltateamtactical.com/Da...rd_p_5777.html
Upper with BCG is $290. So if you have a complete lower, not a bad deal either.