AR9 - 9MM pistols/sbr

I have a first gen MPX. Don't hold your breath on any promises they make. Severely disappointed with Sig's customer service.

I bought the 8" version with the understanding that they would be releasing the other length systems and that the barrels and or complete uppers would be available later. So...gen 2 came and went with no uppers or barrels available. We are now effectively on gen 3 and last I looked at their website and last I contacted them there were still none available.

Sig makes a good product. They also make a lot of promises that they don't keep.

As for the question on gas...I never felt mine was any more gassy than just about any other similar 9mm AR style system. Cannot answer about the newer models.

I have two blowback AR9s that I run suppressed with 8" barrels. Relatively fast, clean powders keep them pretty clean. We have shot them inside the range sheds at Clear Creek from the back wall with just one window open for 30 rounds just to see what it would be like and it was fine. Less obnoxious than the suppressed .223 doing the same thing.

QuarterCircle 10 makes awesome lowers and uppers...this is my AR9 build.

https://i.imgflip.com/1vw7wj.jpg

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Originally Posted by TresMonos

QuarterCircle 10 makes awesome lowers and uppers...this is my AR9 build.

https://i.imgflip.com/1vw7wj.jpg

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I want one of their MP5 mag lower and upper sets.

Looks interesting!!! I’ve read a fair amount about the different magazine formats. It seems the consensus is the Glock magazine variations edge out the colt magazine variations by a bit reliability wise? Haven’t seen anything on the mp5 mag variations but I like the look a lot! Have you had any reliability/feeding issues with the colt magazine variant you have?

Thinking hard about just ordering one of the mp5 mag receiver sets!

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Originally Posted by Ianski

Looks interesting!!! I’ve read a fair amount about the different magazine formats. It seems the consensus is the Glock magazine variations edge out the colt magazine variations by a bit reliability wise? Haven’t seen anything on the mp5 mag variations but I like the look a lot! Have you had any reliability/feeding issues with the colt magazine variant you have?

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Originally Posted by Ianski

Thinking hard about just ordering one of the mp5 mag receiver sets!

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. While the MP5 mag style looks good, you CO guys are stuck with less than 16 round mags.
The colts have had issues, running the magwell insert, while the dedicated lower works, like the MP5 style greater than 15 rd mags are not available in CO . Legally ;)

The glock style offers a more versatile mag capacity. .

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Originally Posted by Ianski

Looks interesting!!! I’ve read a fair amount about the different magazine formats. It seems the consensus is the Glock magazine variations edge out the colt magazine variations by a bit reliability wise? Haven’t seen anything on the mp5 mag variations but I like the look a lot! Have you had any reliability/feeding issues with the colt magazine variant you have?

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I have had some feeding issues with my Colt mag lower AR9. My Glock mag lower AR9's, not as much. It could be due to using aftermarket Colt mags, but I will have to do some more range time/experimenting with the Colt to get it to feed and cycle reliably.

I've had no feeding issues with the factory Colt Mag or the ASC 32rd mags on my Carbine or SBR (both Colt). I haven't shot that much out of the new ones but they have seen 124JHP handloads, FMJ handloads in 115 and 124 as was as FMJ factory loads. I'll be testing some 147 this weekend in the hopes of having subsonic rounds out of the 16" barrel for when my supressor gets to come home. I did have a Colt Carbine quite a while ago and didn't have any issues with the factory mags with 1000s of rounds through it.

I did buy 2 AR Stoner 10 round mags from Midway...they suck.

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Originally Posted by Linkless

I've had no feeding issues with the factory Colt Mag or the ASC 32rd mags on my Carbine or SBR (both Colt). I haven't shot that much out of the new ones but they have seen 124JHP handloads, FMJ handloads in 115 and 124 as was as FMJ factory loads. I'll be testing some 147 this weekend in the hopes of having subsonic rounds out of the 16" barrel for when my supressor gets to come home. I did have a Colt Carbine quite a while ago and didn't have any issues with the factory mags with 1000s of rounds through it.

I did buy 2 AR Stoner 10 round mags from Midway...they suck.

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Thanks for the info, are they ok for range mags?