Angstadt Arms UDP-9 Test Fire Review

| November 5, 2015 | 4 Comments

Last weekend I was able to test fire the Angstadt Arms UDP-9 AR15 pistol. We covered the basics of the UDP-9 in our tabletop review, so this post will concentrate on my experiences firing the pistol and overall reliability.

Test setup

Usually I would run a firearm through at least one class before writing a review, but we’re at the end of the outdoor season here. Here’s my preliminary test with a light volume of live fire.

500 rounds fired

3 magazine stress test drill at 40 yards

4-round bursts at 40 yards

Faster shooting, 4-round bursts at 15 yards

Magazines Used

  • Glock factory 15 round mag, from Angstadt Arms
  • Glock factory 15 round mag
  • Glock factory 31 round mag
  • MagPul 17 round mag
  • KCI Korean 15 round mag
  • KCI Korean 31 round magazine with a Glock baseplate and Wolff spring
  • KCI Korean 31 round factory magazine
  • KCI Korean 31 round magazine with Scherrer +2 magazine extension

Ammunition used

  • Black box Wolf WPA (steel case)
  • Aguila 124gr (brass case)
  • Handloads (brass case)


I was very pleased with the reliability of the UDP-9, especially based on my experience with my Glock enclosures and what readers have said about their 9mm AR15 builds. Out of 500 rounds fired, we had one double feed, which was most likely related to ammunition and not the UDP-9 itself.

Aside from the one problem, all magazines fed reliably and all ammunition fired reliably. Ejection was very strong.

We encountered some problems with the bolt hold open, and I am working with Angstadt Arms to determine if this is a problem with my magazines, the ammunition we used, or the UDP-9. In any event, coming from an AK background I don’t really expect nor care for BHO. There have been plenty of times in handgun classes where a pistol doesn’t lock back on the last round.


I really liked shooting the UDP-9. I think it’s a good size for an SBR / PDW chambered in 9mm, and if you’re familiar with the AR pattern you’ll like the UDP-9 even more. The UDP-9 was easy to handle, lightweight, and was easy to shoot.

Reloading was easy. I think this is mostly due to my training and familiarity with the AR15, but the flared magazine well doesn’t hurt.

I was also to reload the MagPul 17-round magazine without difficulty. I think the angle at which one normally reloads an AR15 reduces the chance of the MagPul 17 mag not locking into place on these early run lowers (note: by the time you read this, any UDP-9 you purchase shouldn’t have this problem).

Despite my initial concern, I was able to use the magazine release easily. The flat release button looked great, but I had doubts if it would be as easy to use as the standard button. It was.

The trigger was nice, but I know some of you will want to put a custom bang switch on it anyway.

I didn’t notice any appreciable benefit or advantage of the B5 Systems grip over the usual MagPul MOE grip I run. The B5 grip is longer, so those of you with big kitten paws may like this over another grip. If I were to SBR the UPD-9 I’d replace the grip with something that has an accessory plug for my paperwork. The B5 is hollow, and does not have a bottom / plug.

It’s not a knock on the UDP-9 at all, but the KAK Industries Shockwave Blade was very uncomfortable for me to shoot over the course of the day. The part of the Blade that contacted my cheek is molded in such a way that cheekweld-only pistol firing resulted in discomfort.


Due to the “floaty” nature of establishing a cheek weld on a buffer tube, the bottom part of the Blade contacted my bicep in different points at different times. I was unable to be consistent, and this made me slow down and I also had to reposition the blade so it did not interfere with my cheek weld.

With the changes this year on how the use of arm braces are interpreted by the ATF, I strongly recommend not any arm brace with the UDP-9 and using a pistol buffer tube with just a piece of foam on the side.

You can avoid all of these issues by registering the UDP-9 as an SBR. I understand this causes some issues with concealed carry of this weapon, or even transporting it loaded in a vehicle.

What’s Next

I have a spare Law Tactical Gen 3-M folding adapter I want to install, and then I will probably head out to a static, indoor range for more test shooting. The team at Angstadt is working with me to see if we can figure out what’s going on with the bolt hold open. I’m not super concerned about it, but we’ll see.

I look forward to putting more rounds downrange with the UDP-9. Expect another summary review after I’m done evaluating it.


The Angstadt Arms UDP-9 was provided by Angstadt Arms for testing and evaluation.

About the Author:

Short Barrel Shepherd Short Barrel Shepherd is a regular guy and works to make Web sites and mobile apps easier for people to use. He spends his free time attending fight-focused firearm, knife, and combatives training, motorcycling, writing, and playing games. His daily carry is a Glock 19 pistol and an AR15 .300 Blackout pistol in a backpack.

4 Comments on "Angstadt Arms UDP-9 Test Fire Review"

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  1. Matt says:

    This is very interestng, thank you for the fire test. Do you think this is something that would compete for carry time with your 300 blk?

    • Short Barrel Shepherd Short Barrel Shepherd says:

      Great question. I am going to answer that after I’ve done some more testing.

      I think the UDP 9 (and 9mm ARs) have a very specific role and will be more desirable to some people over others.

      More to come.

  2. Terry says:

    FYI – Angstadt has a couple of videos showing test firing with a suppressor

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