AR 9 anybody build one? thoughts tips advice

[2c1fr]

Hey y'all so I bought a 9mm lower the other day from my LGS serial number 26! anyways it takes glock mags and I am wanting to build this thing up so have any of y'all done one anything that stands out that I need to know right away?

 

[Steel head]

I did earlier this year.
It's pretty fun to shoot.
Heavy bolt and buffer and your usually ahead if you get the bolt and barrel from same manufacturer to get a proper headspace.
I didn't and my headspace is not optimal but it still functions.

 

[2c1fr]

I like that steel head thanks for letting me know!

 

[Waorani]

Check out the pistol caliber forum on the big AR forum. Lots of good info w/o a lot of the usual bs on that site.

 

[TonyTheTiger]

Enos has a huge pile of PCC build info too. There's a little more to getting one running than I would have assumed, it pays to learn ahead of time.

 

[atxhorn4425]

Enos has a huge pile of PCC build info too. There's a little more to getting one running than I would have assumed, it pays to learn ahead of time.

This. They're a lot of fun and once you've got it up and running they're pretty damn reliable, but component selection can be a little finicky. There are a number of triggers, for example, that just won't work with certain 9mm bolts. My personal build uses a JP 9mm Enhanced Bolt and 9mm Silent Capture Spring, and those work really well together.

 

[kingzero]

Mine is one of my favorites to shoot. Handy, low recoil and reliable. I got my lower, bolt and barrel from QC10 to avoid possible problems of mixing brands. I run a standard Timney AR trigger with zero problems and heavy stainless buffer and extra power spring to slow the cycle rate down. It runs like a champ with and without the suppressor and with both subs and supers.

 

[2c1fr]

King zero nice rig!

 

[atxhorn4425]

Sweet looking piece. Here's mine, went the PDW route with a 5" barrel and Maxim Defense stock.

 

[mi223]

Any one run the palmetto upper and lower. They have been on sale pretty regular lately. Hate to spend a ton on something i would consider a novelty gun. Though I am sure i would have a blast with it.

Sent from my SM-G930P using Tapatalk

 

[Steel head]

I'm using the PSA Glock lower without lrbho option.

 

[bfoosh006]

I have a 16" PSA Hybrid Colt pattern....after a little tinkering and polishing , it runs great

Do not be surprised by the blow back actions recoil... I tried tons of different buffer weights and springs to help mitigate the "bark and blast".

If you decide to change buffer weights and springs... I suggest you buy .. Tubbs Flatwire .223 and .308 springs, and the KAK 9MM configurable extended buffer.

The buffer is fully configurable up to 10.0oz weight ( bear with me ) ....

I do not suggest solid heavy weight buffers... you need the dead blow effect of the carrier weights. ( Imagine a steel hammer banging an anvil.. it bounces... a deadblow hammer smacks with a much more solid thud.

As for the springs.... you don't want the moving mass of the BCG and buffer smacking the breach face so hard that it causes muzzle dip....

My 16" finally ended up with .308 Tubbs Flatwire, and the KAK configured to about 7.5oz... it runs like a top... changing the "violent" OEM Linda Blair ( Exorcist ) recoil into a very manageable recoil.


A lot of people might think you could go over board with springs and buffers... just so everyone knows I tried clear up to a 10oz buffer and the Sprinco .308 Carbine spring... the 9MM would function 100% .... but man, all I did was move the recoil to the breach face !!!


Various spring weights...

Here are some spring weight measurements from David Tubbs... just food for thought.

A2 (old) - 7.6lb closed, 14.5lb open
A2 (new) - 9.1lb closed, 16.7lb open
Tubb Flatwire - 10.5lb closed, 16.3lb open
Tubb .308 Flatwire - 13lb closed, 16.7lb open
SpringCo White ? (standard) - 8.3lb closed, 16.3lb open
SpringCo Red (extra) - 10.5lb closed, 18.4lb open
SpringCo Orange (increased) - 13.9lb closed, 24.8lb open


IMHO, an XX power spring isn't needed , nor wanted.... you can see the .308 Flatwire has the pressure where you want it... on the closed bolt.

I tried the "Orange" ... it caused needless muzzle dip, and was slamming the BCG really hard into the breach face.

 

[Niles Coyote]

Great info, thanks for sharing!

 

[sheepdog697]

I think that buying a lower that is compatible with glock mags if you already have them readily available is a great start. If that wasnt the case, ive shot the colt ar9 in 16" and those guns run pretty good.

 

[Not_A_Llama]

I like mine a lot, built as a QC10 Colt mag pistol. One thing to be aware of - these are not low recoil guns. Unlike most handguns, these are straight blowback guns, and have something like a pound of reciprocating mass. I actually like it, from a training perspective, as it's more applicable to 223 training than my nearly-worthless 22 conversions.

 

[propeine]

I built a DI one because 9mm shouldn't have more recoil than 223...it uses modified Colt SMG mags and an extremely short gas system, custom gas block (straight height) with a .120 gas port. 5.375" barrel. It has a hard time running subsonic unsuppressed but it works with hot supers. Subs and a suppressor run fine though.

https://youtu.be/lN04LB6d2is