Glock’s slim-line series — the 43, 43X, and 48 — occupies the thin-pistol segment of their lineup. All three are single-stack or thin double-stack 9mm designs built around maximum concealability. They are mechanically similar in many ways and confusingly different in the details that matter most. Here is what separates them and who each one is for.
The Glock 43: The Original Slim
The G43 was Glock’s first purpose-built slim single-stack 9mm, released in 2015. Before it, Glock had no answer to the single-stack carry market that Kahr, Smith & Wesson Shield, and Springfield XDS were winning. The G43 fixed that.
Specs:
- Barrel: 3.39 in
- Overall length: 6.26 in
- Height: 4.25 in
- Width: 1.06 in
- Weight unloaded: 17.99 oz
- Capacity: 6+1 standard
The G43 is the smallest and lightest pistol in this comparison. It is a genuine deep-concealment option — it disappears under almost any clothing in an appropriate holster. The tradeoff is capacity (6 rounds standard) and shootability (the short grip gives minimal purchase, making recoil management harder than either the 43X or 48).
For deep concealment as a primary carry gun, the G43 works. As a first Glock or a primary training platform, the limitations of the short grip become apparent quickly. Most shooters who start with a G43 end up wanting more gun within a year.
The Glock 43X: Longer Grip, Same Slide
The G43X was released in 2019 alongside the G48. It uses the same slim slide as the G43 but with a significantly longer grip — matching the G48’s frame.
Specs:
- Barrel: 3.41 in
- Overall length: 6.50 in
- Height: 4.41 in (vs 4.25 in on the G43)
- Width: 1.10 in
- Weight unloaded: 18.70 oz
- Capacity: 10+1 standard
The 43X is the most interesting model in the lineup because the longer grip dramatically improves shootability while maintaining nearly the same slide profile as the G43. The extra grip height means a full three-finger purchase for most shooters, which changes the recoil management equation significantly.
The 43X also has an aftermarket advantage: the Shield Arms S15 magazine fits the 43X frame and delivers 15 rounds of 9mm — equal to the G19 — in a frame that is significantly thinner. This effectively turns the 43X into a high-capacity slim pistol, which changes its value proposition considerably.
The Glock 48: Same Frame, Longer Slide
The G48 uses the same grip as the G43X but with a longer slide — matching the G19’s barrel length (4.17 in) rather than the G43’s shorter slide.
Specs:
- Barrel: 4.17 in
- Overall length: 7.28 in
- Height: 4.41 in
- Width: 1.10 in
- Weight unloaded: 20.74 oz
- Capacity: 10+1 standard
The G48 is the slim-line option for shooters who want a longer sight radius and better accuracy potential without increasing the width of the pistol. It is also available in an MOS (optics-ready) configuration — the G48 MOS is one of the best slim-line optic-ready options on the market.
The G48 is slightly harder to conceal than the G43X due to its longer barrel, but the difference is primarily about barrel printing under untucked shirts rather than grip printing. For carry under a jacket or with appropriate cover garments, the G48 conceals well.
Side-by-Side Comparison
| Spec | G43 | G43X | G48 |
|—|—|—|—|
| Barrel | 3.39 in | 3.41 in | 4.17 in |
| Height | 4.25 in | 4.41 in | 4.41 in |
| Width | 1.06 in | 1.10 in | 1.10 in |
| Capacity | 6+1 | 10+1 | 10+1 |
| S15 mag compatible | No | Yes | No |
| MOS available | No | No | Yes |
Who Should Buy Which
Buy the G43 if: Deep concealment is your absolute priority and you accept the capacity and shootability tradeoffs. Good as a backup gun or for carry in very restrictive clothing environments.
Buy the G43X if: You want the best balance of concealability and shootability in the slim-line lineup — particularly if you plan to run Shield Arms S15 magazines for maximum capacity in a slim package. This is the most versatile of the three.
Buy the G48 if: You want a slim pistol with a full-length sight radius and are considering mounting an optic. The G48 MOS is the purpose-built option for optic-equipped slim carry.
The Glock 43X with Shield Arms S15: A Closer Look
The Shield Arms S15 is a 15-round steel magazine that fits the G43X and G48 frames. It is the most significant aftermarket development for these pistols since their release.
Running S15 magazines in a G43X gives you 15+1 capacity in a pistol that is 0.16 inches thinner than a G19. For shooters who prioritize thin over small, this is a compelling combination. The S15 requires a Shield Arms magazine release (the OEM plastic release wears the steel magazine too quickly) — a $30 part that installs in minutes.
Shop the slim-line lineup: Brownells carries all three models with current pricing. For Shield Arms S15 magazines and the required Shield Arms magazine release, search Shield Arms S15 on Amazon.
Sources:
- Glock slim-line specifications — glock.com
- Shield Arms S15 magazine specifications — shieldarms.com
- RECOIL Magazine, G43X vs G48 comparison, 2019