80 Percent Arms GST-9 80% Glock Frame Review

In October 2019 80 Percent Arms announced plans on creating their version of an 80% Glock frame. Named the GST-9. They began taking preorders the following month in November. After prototype testing and securing manufacturing during the COVID19 pandemic they began shipping final production models to the customers that preordered them in November. Those shipments reaching their new owners the week of May 18th.

Since Polymer80’s introduction of their 80% Glock frames about five years ago they held the market on “homemade’ Glocks. Now 80 Percent Arms have entered the arena. For the most part they are similar. With the the more traditional 1911 grip angle, being about 19 degrees off square. As opposed to the Glocks often complained about 22 degree off square angle. All the milling points remain the same, as well as metal rail components. All compatible with 3rd generations parts, both OEM and aftermarket parts.

The two major differences are,
1. The modular grip. The bottom portion of the grip is interchangeable with two varying length grips. One that is shorter creating the option for the standard G19 length or a longer G17 length grip.depending on users preference.

2. Unlike the Polymer80 Glock lower, the GST-9 is compatible with all Glock holsters. This is because the Polymer 80 lower receivers frame have a little extra girth on the front end above the rail mount.

There are a couple of drawbacks though. These are just being nit picky in this writers opinion. You’ll have to settle for a G19 for your slide and barrel length. As of this writing there are no plans to create a G17 compatible lower. Second, for those that are into customizing and stippling your own grip, there is no option to purchase a blank or plain grip like Polymer80 does.

Also to note is that the federal governments/ATF now require that 80% lower receivers aren’t allowed to be sold with a jig included. So the jigs must be purchased separately.

The overall quality and feel of the polymer used in this frame seems solid and sturdy. The stippling used on the grips seems minimal, but is more than sufficient enough for your hands and fingers, be it with or without gloves.

Received mine on May 19th. Only takes about 30 minutes to an hour to complete the milling depending on your experience and skill level. i was only able to take it on a test run today, May 22nd. Frame held up well and no real issues with it or any type of malfunctions with the lower parts. I put a little over 200 rounds through it and the only FTF’s was due to the cheap range ammo I brought. Even still it was only two rounds not fully ejecting because they were a little warped. Not a real torture test by any means, but I did see how it stood up to double and triple taps as well as a rapid fire mag dump. It ran smooth with no real issues.

Check out our video of the GST-9 in action below.

With the preorders being so successful and still being filled, currently you’re only able to be added to a waiting list to. 80% Arms being the only online retailer you can purchase this from, but if it proves to be successful enough I’m sure the same retailers that offer the Polymer80 frames will sell these as well. Currently the price for the frame is $119.99 and the jig at $29.99 it still comes in lower price point than the competition.

Overall this seems to be just as good as any standard Glock lower frame and Polymer80 frame. I would recommend it if you’re looking for an alternative to what’s currently available. The modularity of the lower is what drew me to try it out. The length of a G19 with the handle of a G17.

Great job to the crew of 80percentarms.com on a new and quality product and the ability to make through given the limitations of manufacturing with most states on COVID19 lockdowns and restrictions.

Check out all our past reviews on our Reviews Page.