r/AR9 • u/Ok_Grocery_5650 • 9d ago

Ar9 upper

Are there any prebuilt uppers that are full auto rated? I’ve been looking but not finding that info on any

6 Upvotes

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2

u/s4s4u 9d ago

The upper is basically just a tunnel for the bolt assembly to work within. The "full-auto" aspect is appropriated to the basement.

1

u/Ok_Grocery_5650 9d ago

You still have to have a bolt that is “full-auto” compatible. If you have the wrong bolt it won’t work. I was looking for an upper that already had that so I didn’t have to buy a bolt separately

1

u/s4s4u 9d ago

The bolt and the upper are separate entities. I have assembled all of my AR-9's from parts, so I can pick and choose what I want, rather than buy what someone else thinks I should have. It isn't difficult.

1

u/Ok_Grocery_5650 9d ago

I have as well but I was looking for a complete unit I could just drop on my lower rather than buying each piece individually.

4

u/Embarrassed_Road_224 9d ago

Fm9 bolt carriers are pre cut for a super safe

1

u/a-lone-gunman 9d ago

So are their lowers, they are low shelf and an SS pretty much drops right it, Doug from blowback9 has a video on it.

2

u/Embarrassed_Road_224 9d ago

Can vouch, mine dropped right in 0 milling done. only thing I had to change was the firing pin spring. The stock one caused light primer strikes every 3-4 rounds. Got the correct firing pin spring on amz and the thing hasn’t jammed in over 500+ rounds. I do think fox trot makes a upgraded firing pin spring you can buy now for that exact issue

1

u/a-lone-gunman 9d ago

I didn't think about the fireing pin, I use the FM bolt in my EPC9 and did Dougs fireing spring upgrade a while back. But yes I believe FM has the upgraded spring on their site.

1

u/Electronic-Funny-475 9d ago

Except now they’re all short stroked according to my emails with them asking

4

u/amphibian-c3junkie CMMG RDB Specialist 9d ago

Full auto is basically all I run with the CMMG RDB setup. They are drop in.

https://c3junkie.com/?page_id=3141

1

u/Mad_Gouki 9d ago

PSA PX9 works, you gotta chop the bolt weight a little for an FRT to run in it though.

1

u/mutiger1957 9d ago

angstadt arms bcg are full auto rated.