Fostech Echo in 9mm SBR integrally suppressed

AR-15 » Rimfire and Pistol Calibers

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[ARCHIVED THREAD] - Fostech Echo in 9mm SBR integrally suppressed

Posted: 4/1/2017 8:38:19 PM EDT

Playing with the Echo
https://youtu.be/j2qtYf_g95c

Posted: 4/2/2017 6:08:01 PM EDT

[#1]

That's cool! What are the specs on the rifle? I'm working on a 9mm AR right now and the Fostech trigger is something I was considering.

Posted: 4/2/2017 9:37:19 PM EDT

[#2]

Nice I wish I could get mine to work with the suppressor attached. I get double feeds in ECHO mode when I use the can. Its either the buffer or the size of the matrix arms ejection port. I'm not sure which one right now anymore. However here it is without the suppressor. Its super fast!

https://goo.gl/photos/rmQZ3RnMA39Udya87
https://goo.gl/photos/WuyR4SdfpcJDiom3A

Posted: 4/2/2017 10:00:59 PM EDT

[#3]

Quoted:
Playing with the Echo
https://youtu.be/j2qtYf_g95c

View Quote

Fostech Echo trigger in AR15 9mm suppressed

https://www.youtube.com/watch?v=j2qtYf_g95c

Posted: 4/3/2017 10:21:02 PM EDT

[#4]

Quote History

Quoted:
That's cool! What are the specs on the rifle? I'm working on a 9mm AR right now and the Fostech trigger is something I was considering.

View Quote

The specs: it started as a 16" RRA upper chopped down to 6" with a suppressor than screws on the breech end on the barrel like a MP5 SD. This keeps the back pressure low, I also made a longer buffer out of 304SS and added some lead shot inside the buffer to dampen it. It's approx 12 oz.

Posted: 5/17/2017 10:22:14 PM EDT

[#5]

I'm looking to build something similar with the 9mm setup. Are you using a specific bolt carrier with the Fostech trigger?

I've read a lot of people having issues with the suppressor attached, would you say the buffer weight has a lot to do with that? Also, are you using any certain spring?

Currently I just have a stripped RRA upper and lower, just trying to plan my grocery list. Any advice is greatly appreciated!

Posted: 5/17/2017 10:40:18 PM EDT

[#6]

I'm using a spikes bolt but any should work the same. The buffer is one I turned out of stainless and is roughly 12oz which is a huge help to quiet the gun down and slow the bolt. The spring is a standard carbine spring

Posted: 5/17/2017 11:51:14 PM EDT

[#7]

Awesome, thanks for the info! Hopefully I can nail the setup on the first try.

Posted: 5/18/2017 12:23:19 AM EDT

[#8]

I thought the echo requires a proprietary carrier?

Posted: 5/18/2017 1:41:37 AM EDT

[#9]

Quote History

Quoted:
I thought the echo requires a proprietary carrier?

View Quote

Just a bit of metal taken off the back to keep the trigger lock engaged. You actually get better results by not using fostechs carrier and demeling it yourself. On a 9mm your only option is to dremel it but it works fine once you have done it

Posted: 5/18/2017 10:45:46 PM EDT

[#10]

So I would in fact need to modify the 9mm bolt carrier to work properly with the Echo trigger? That was one of my concerns but I've been seeing videos pop up with people using it with 9mm AR's.

Does anyone have a diagram of what would need to be modified?

I looked around for a Spikes bolt but wasn't able to find one so I was going to go with the Faxon bolt.
http://faxonfirearms.com/faxon-9mm-pcc-blowback-full-mass-bolt-carrier-group-complete-nitride/

Posted: 5/19/2017 2:29:31 AM EDT

[#11]

Quote History

Quoted:
So I would in fact need to modify the 9mm bolt carrier to work properly with the Echo trigger? That was one of my concerns but I've been seeing videos pop up with people using it with 9mm AR's.

Does anyone have a diagram of what would need to be modified?

I looked around for a Spikes bolt but wasn't able to find one so I was going to go with the Faxon bolt.
http://faxonfirearms.com/faxon-9mm-pcc-blowback-full-mass-bolt-carrier-group-complete-nitride/

View Quote

Here is a picture of a 5.56 carrier I modified. Just takes a few minutes with a dremel. Factory echo carrier on top. You just angle the m16 trip face slightly.

[ARCHIVED THREAD] - Fostech Echo in 9mm SBR integrally suppressed

AR-15 » Rimfire and Pistol Calibers

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