I’m thinking about adding a 9MM pistol to the mix...I have read mixed results on adapting a 9MM upper to standard AR lower...I have two pistol lowers built for .556 and .300 BO and plenty of 9MM Glock extended magazines. Is it worth the trouble or should I just buy a PSA pistol?

Stick with good reliable and proven parts and you should be okay. I run an integrally suppressed 9mm upper on a standard RRA lower with a bottom loading 9mm Hahn block. It runs ANYTHING I put in it. You will need a ramped 9mm BCG and a M16 style hammer with the notch removed for your FCG.

I used a Stern (Glock pattern) adaptor. It was good to go and solid.

The Hahn block solves the mag problem for Colt 9mm mags and it totally reliable, But I don't think they have a glock version. In any case I have no experience on any glock insert, instead using dedicated lowers. But solving the rest if there is an insert that works just takes a bit of finesse on the upper to make sure that the 9mm bolt you are using and the hammer you are using all are happy.

IF you get a CMMG Banshee you can use regular 5.56 lowers with an endomag.

Mine runs great.

Not that it matters very much, but the endomag does not need a specific upper like a CMMG. It runs on most everything (bolt, hammer, buffer etc. to be right for 9mm)
j\

quote:

Originally posted by hrcjon:
Not that it matters very much, but the endomag does not need a specific upper like a CMMG. It runs on most everything (bolt, hammer, buffer etc. to be right for 9mm)
j\

That's true but with the CMMG radially delayed blowback, you get better suppression, less recoil, and you can use it on an existing SBR lower that you already have for 5.56. No need for a heavy 9mm buffer. You can use standard triggers and you don't have to worry about breaking hammer pins the way that blowback 9mms are known for.

I just watched a YouTube video on the Endomag...you can just buy the “guts” to install in the PMag...I like it

i would buy a dedicated lower. Look at Foxtrot Mikes lower. If you want the pistol version it is good to go. Well made product and good price too.
There are three of four places to buy and look for a coupon for additional savings.

quote:

Originally posted by IndianaBoy:
That's true but with the CMMG radially delayed blowback, you get better suppression, less recoil, and you can use it on an existing SBR lower that you already have for 5.56. No need for a heavy 9mm buffer. You can use standard triggers and you don't have to worry about breaking hammer pins the way that blowback 9mms are known for.

Your post made me look into the pluses of the CMMG upper compared to the straight blowback options...after doing more research on the net and YouTube...I opted to take your advice and ordered an 8” CMMG upper ... I like the magazine design and the fact that the BCG uses a standard carbine buffer and spring so it will be easier for me to swap uppers between the 9MM and .300 BO....thanks everyone for their input...I’m looking forward to getting this upper...now to order the Endomag innards

I ended up getting a Glock 9mm lower because it was cheaper than the magazine block. 179.99 got the adapter 129.99 for a lower. Something to think about perhaps.

The endomags don't use the adapter so you skip that cost, as well as a different lower. I'm not sold on them as the cost for a bunch of them (and I always have a bunch of everything) exceeds the cost of a lower for the glock or colt mags you already have.

Only real reason to do a mag block over a dedicated 9MM lower is if you have an SBR'ed 5.56 Lower.

I get the whole 'conversion' thing, but over time I just like to set shit up and leave it the way it is.

Using a 5.56 lower with a mag block seems so 5 years ago. With the huge increase in popularity of 9mm ARs in the past few years it seems that everyone now makes 9mm lowers that are slimmed down and lighter. Lowers are so cheap there is no need to only have one lower and switch back and forth.

Guy at my club shoots endomags. I think the design is wicked smart. They are pricy though and at the end of the day a dedicated lower or even a magblock seems like a better option. I agree with ORC. Foxtrot Mike is the lower I bought. Nicely made no issues other than a little flashing in the pivot holes easily corrected. I bought one of their uppers as well. I bought the forward assist. I recommend the standard version. I would do that slightly differently.

Edit: I said forward assist when I meant to say forward charging handle.

This message has been edited. Last edited by: pedropcola,

I had a PSA Colt pattern mag block and it ran with zero issues. But you have to remove the bolt catch to remove the adapter which is a pain if you want to swap calibers.
I then bought some Endomags and they work just fine but get expensive after awhile.
I now have a dedicated Colt Pattern lower.
Sold the adapter and kept a few endomags.
My first build was before pistol braces so the SBR is still registered as a 9mm so I keep the endomags to stay in compliance for the SBR.
I’ll likely reclassify the caliber down the road.

The SBR lower is only for one caliber? I did not know that.

quote:

Originally posted by pedropcola:
The SBR lower is only for one caliber? I did not know that.

No. You can have multiple uppers in multiple calibers and use them on one SBR lower.

quote:

Originally posted by Bisleyblackhawk:

Your post made me look into the pluses of the CMMG upper compared to the straight blowback options...after doing more research on the net and YouTube...I opted to take your advice and ordered an 8” CMMG upper ... I like the magazine design and the fact that the BCG uses a standard carbine buffer and spring so it will be easier for me to swap uppers between the 9MM and .300 BO....thanks everyone for their input...I’m looking forward to getting this upper...now to order the Endomag innards

You will be glad you did. The RDB is much smoother than a blowback 9mm. The endomags are super slick too.

quote:

Originally posted by IndianaBoy:

quote:

Originally posted by pedropcola:
The SBR lower is only for one caliber? I did not know that.

No. You can have multiple uppers in multiple calibers and use them on one SBR lower.

Correct but the lower has to be registered as a specific caliber and you need to be able to put it back to that caliber. (Unless something has changed since I built mine many moons ago before the brace was a thing).

Since I don’t have the block anymore I keep the endomags so it can go back to 9mm.