DAILY DEAL Exp. 10/17, 12pm EST
PSA Gen4 8" 9mm 1/10 Nitride 7" Lightweight M-Lok Upper - With BCG & CH - 5165449737

More Views

PSA Gen4 8" 9mm 1/10 Nitride 7" Lightweight M-Lok Upper - With BCG & CH - 5165449737


Quick Overview

It is the customer's responsibility to be aware of all applicable laws and regulations regarding the purchase and ownership of uppers with a barrel length of less than 16". Federal NFA regulations are applicable to this item.

WARNING: This product can expose you to the chemical lead, which is known to the State of California to cause cancer and reproductive harm. For more information go to www.p65warnings.ca.gov (CA Health and Safety Code Section 25249.6).

SKU: 5165449737
UPC: 5165449737
MFR#: 5165449737


Barrel Length: 8"
Barrel Profile: Heavy
Barrel Steel: Chrome Moly Vanadium 
Barrel Finish: Nitride 
Chrome Lining: No
Muzzle Thread: 1/2-36
Chamber: 9mm (9x19)
Twist Rate: 1 in 10"
Barrel Extension: 9mm
Muzzle Device: A2 Style Flash Hider
Receiver Material: Billet 7075 T6
Receiver Type: Slick Side 
Handguard Type: PSA 7" Lightweight  M-Lok Rail
Bolt Included: Yes, (Gen 4, Hybrid)
Bolt Steel: 8620, Nitride Treated 
Charging Handle included: Yes

Add To:

Barrel: 8" chrome moly steel barrel. Chambered in 9mm, (9x19), with a 1/10 twist. The barrel is nitride treated for durability and finished off with a Palmetto State Armory 7" Lightweight M-Lok free-float rail and a 9mm birdcage flash hider. 

Upper: Billet 7075-T6 A3 AR upper is hard coat anodized black for durability.  These slick side upper receivers are made for us right here in the USA.

Bolt Carrier Group: Gen 4 Hybrid 9mm BCG.  Nitride treated 8620 steel, with an enhanced firing pin and external 5.56 style extractor. The bolt carrier group is compatible with most aftermarket fire control groups. 

SKU: 5165449737
SKU 5165449737
Department Uppers
Brand Palmetto State Armory
Daily Deal Yes
Daily Deal Expires 10/17
Unit Price No
Youtube Video No
Free Shipping? No
Free Shipping Qty Label No
Free Shipping Qty No
SKU: 5165449737

Questions and Answers

Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 48 questions Browse 48 questions and 84 answers
Will this upper work with a standard weight buffer, or does it need a heavier buffer?
Ben R on Oct 14, 2018
BEST ANSWER: I currently use an 8.5 oz buffer from Slash's Buffers and so far it's been good to go. I wouldn't go less than 7oz if you ask me. I noticed with the 6oz range of buffers recoil was very noticeable. Hope this helps.
can I use my ar-15 lower with this upper receiver?
Junior on Oct 9, 2018
BEST ANSWER: Yes but you need a 9mm conversion block for the lower.
What are the improvements/changes over the Gen 3?
V L on Jan 11, 2019
What buffer would you recommend for this upper?
Robert K on Oct 14, 2018
BEST ANSWER: While a 5.6 oz will work, I changed to an extended 7.5 oz and ejection of brass went from 20 feet to 8 feet.
Is this upper compatible with Glock magazines?
Mike L on Oct 5, 2018
BEST ANSWER: The Bolt is "Hybrid' so it should work with Glock magazines in your lower.
Will this work with a Stern Defense MAG AD9 magazine adapter? I have heard the BCG will not.
Joe L on Jan 20, 2019
Is there a recommended magwell block to run this upper with standard lower receivers?
Mike E on Dec 28, 2018
Is this considered a “Glock cut bolt”?
Joe L on Jan 20, 2019
BEST ANSWER: This is a hybrid "cut bolt" and is designed to work with both Glock mags and Colt mags. I have installed this upper on lowers that use both types of magazines and it functioned flawlessly on both.
Can the flashhider be removed or is it pinned and welded? I
SEAN N on Oct 29, 2018
BEST ANSWER: It can be removed
Is this compatible with a angstadt arms lower? If yes what buffer and would I need?
Block on Nov 8, 2018
BEST ANSWER: I assume your referring to the UPD-9. I don't own one so don't take my word for it but looking at a picture of it , it appears to be a standard AR 9 lower so it should fit and function fine. The buffer and spring that is already in it should work no problem.
What is the thread pitch under the flash suppressor?
Christopher M on Nov 21, 2018
BEST ANSWER: Description says 1/2 x 36
will this work with the spikes tactical lower?
Gavin E on Mar 10, 2019
BEST ANSWER: Short answer is yes. This will work with any brand of mil spec AR 15 lower with a mag block. This will also work with any brand mil spec pattern 9mm Glock or Colt style lower. I built mine with an 80% Arms 9mm Glock lower.
can this be shipped directly to me??
Ernie on Mar 4, 2019
I have the Spike's Tactical pistol buffer tube assembly with the T2 buffer. Is this a good match for this upper?
Michael H on Nov 19, 2018
BEST ANSWER: The buffer tube is fine and while the T2 would work it will probably cause issues like a decrease in dwell time of the blowback system, possible bolt bounce and firing out of battery... you should use a heavier buffer that was designed for the 9mm blowback system. PSA has 8oz and 10oz 9mm pistol buffers which would be better to use.
Yankee Hill Machine 9mm Bolt Buffer YHM-925-A
Yankee Hill Machine 9mm Bolt Buffer YHM-925-A
9MM Steel Body Buffer Assy - 482667
9MM Steel Body Buffer Assy - 482667
PSA AR-45 8oz Buffer - 516446103
PSA AR-45 8oz Buffer - 516446103
PSA AR-45 10oz Buffer - 516446104
PSA AR-45 10oz Buffer - 516446104
PSA Custom AR-9 9mm 8.5 oz. Enhanced Fluted Buffer - 781107
PSA Custom AR-9 9mm 8.5 oz. Enhanced Fluted Buffer - 781107
PSA Custom AR-9 9mm 8.0 oz. Enhanced Fluted Buffer - 116006
PSA Custom AR-9 9mm 8.0 oz. Enhanced Fluted Buffer - 116006
Can you attach this to a Freedom Ordnance lower?
Tomsass24 on Nov 5, 2018
BEST ANSWER: If your referring to the FX9, I do not believe it will fit. The FX9 is an AR type rifle and that is only in its looks and ergonomics, the rear takedown pin is too far forward and the part ot the receiver that the buffer tube screws into is much thicker than a AR9/AR15 receiver.
When it says it will run on most fire control groups. Does that mean it will run on a standard ar15 trigger? As in a cmc trigger
Dan C on Dec 27, 2018
BEST ANSWER: Yes. Any Mil-Spec trigger will work along with most any drop in cassette trigger. I say most any because I'm sure there's one somewhere that wont.

I personally have this upper with a PSA lower and a CMC Lantac trigger. It's worked 100% over thousands of rounds. Make sure you install anti-walk pins at the same time as the trigger.
Does it hold bolt open after last round is fired?
Mikemotorcycle on Apr 18, 2019
BEST ANSWER: LRBHO will be determined by the lower receiver you choose, not the upper. As far as I know only one AR9 design on the market has LRBHO on the upper and it's made by New Frontier. I dont recommend that one due to too many proprietary parts.
Doesn’t it work with other Lowers?
Tyler L on May 23, 2019
BEST ANSWER: The upper I have is extremely accurate. I have used it with a PSA 9mm Glock configuration pistol lower (dimensions of PSA Glock lower are same as a 223 lower, only the mag well is different ) and it works fine. I can only confirm it works fine on a PSA 9mm Glock style 223 style pistol lower. Be sure you understand and comply with the ATF rules regarding the use of AR style short barreled uppers.
Is the barrel 8” before or after the flash hider?
Asa P on Dec 29, 2018
BEST ANSWER: It’s before the flash hider. The measurement is taken at the end of the barrel after the threads.
I see it says the mussel threads are 1/2-36, is this a misprint or are they really that?
Mark W on Apr 23, 2019
BEST ANSWER: Yes on 9mm barrels the thread pitch is 1/2 by 36
Will this upper work with a lower that takes MP5 mags?
Chad C on Apr 21, 2019
BEST ANSWER: My understanding when i bought this upper is that it worked with Glock or Colt mag's only. I use Glock myself. The lower I purchased was the ar-9 lower from 80 percent arms.
Does this upper lock after last round fired?
Bill A on Oct 28, 2018
BEST ANSWER: The control for last round lock is part of the lower assembly not the upper.
Will i be able to attach any Mil-Spec handguard to your AR9 upper?
Brink on May 25, 2019
BEST ANSWER: This is a free float hand guard with a barrel nut that attaches to them upper receiver. Depending on what you mean by “Mil-spec” handguard the answer will be different. If you are talking about the A2 style 2 piece heat shield it will not. If you have a free float handguard that has a barrel nut all the upper receivers are the threaded the same and it will fit.
Does it have a full auto BCG?
Scott on Apr 17, 2019
Does this upper work well with the Stern mag block conversion?
Richard H on Mar 8, 2019
BEST ANSWER: Could not work any better. Works well with both 115 and 124 gr. Bullets. Would buy again.
Would this require a tac stamp when fitted with the hybrid moe lower?
Corey on Oct 24, 2018
BEST ANSWER: If you don't use a pistol lower,and use a regular ar-15 rifle lower. It would make it a SBR Class 3,and you would need a tax stamp..
Does this upper function with an AR-15 pistol lower or is it AR-9?
JAN J on Oct 5, 2018
BEST ANSWER: Not exactly sure what your asking, but it will fit on essentially any AR pattern lower. If using a standard AR lower, you will need a mag well block to adapt to 9mm magazines. If by "AR-9" you mean a lower that is already designed to take 9mm magazines, it should function with them too.
Will this upper work with EndoMags?
John N on Jul 10, 2019
BEST ANSWER: Mine works well with endomags
Can this be attached to a Diamondback DB9RB lower?
Harvey R on Apr 18, 2019
BEST ANSWER: It should fit mil- spec lowers
Can you change the rail on this to one that extends out past the end of the barrel? Also anyone know the Inner Diameter of the rail?
Nic P on Mar 15, 2019


4.8 / 5.0
53 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
October 1, 2019
2 months ago
AR9 9mm pistol
Can you believe I haven't been out to shoot it yet or the 10.5 inch 5.56 pistol I also got from PSA. They both look awesome so hopefully they will perform great.

Between moving and health issues I have been pretty busy.
September 19, 2019
2 months ago
I enjoy shooting it.
Fits and shoots well.
September 17, 2019
2 months ago
Solid and pretty!
Love this 9mm 8” I’ve shot 190 rounds so far with no issues. I using a 6.3 oz buffer.
I’m using the Mean Arms Endomags and I love them as well.
User submitted image
September 2, 2019
2 months ago
A sweet 9mm upper.
I put this upper on a CMMG Colt style mag 9mm lower with Kak brace...what a sweet shooting gun!
So far 500 rds through it without any malfunctions.
September 1, 2019
2 months ago
August 10, 2019
3 months ago
Very impressed!
Built an 80% lower and put this on it, very accurate to 70 yards and a lot of fun to shoot, will be possibly building another one!
August 4, 2019
5 months ago
Really fun 9mm AR pistol
I love this AR 9mm pistol. Coupled with a Glock mag PSA lower. Lots of fun.
I dressed it up a little back in June and named it “Little Patriot” just in time to take it out to the range for the 4th of July.
I have several hundred rounds though this blaster and it runs great both with and without a suppressor. When suppressed it get supper cruddy inside but it keeps functioning without any failures.
I did have on issue with the ejector coming loose in the lower. This happened within the first 100 rounds through it. I removed it and used a drill to dimple it where the set screws contact it and then used blue on the set screws.
User submitted image
User submitted image
August 4, 2019
6 months ago
A blast to shoot
Great little upper. The most fun I've had shooting in years.
July 23, 2019
4 months ago
Very fun to shoot , with very little recoil.
I like how it shoots,I changed the barrel to a 16 inch and able to hit my target @ 100 yards!
User submitted image
Added Jun 30, 2019
June 30, 2019
5 months ago

Customers Who Viewed This Item Also Viewed