Sig Sauer 9mm MPX K

Last updated March 2026 · By Nick Hall, Sig MPX K shooter who has fired this 9mm submachine gun platform

Sig Sauer MPX K

• Caliber: 9mm
• Barrel: 5.5 inch

A few days ago I wrote about the awesome HK SP5K. It’s a great gun, but it led me to this Sig MPX PDW 9mm.

How could I forget this gun that is basically a step up at every point?

It’s cheaper, it’s a match on the spec sheet and, we have to be honest, it looks better too.

Sig Pistol Is A Rifle Too

You can buy a stock and turn it into a rifle, too. So the Sig 9mm is one of the most versatile weapons on the market.

It’s beautifully engineered. The barrel is basically one big Picatinny rail, so you can get comfortable and it has a wealth of access points for modular components.

So you can have a rifle with additional cheek rests, optics  and more.

Sig MPX: Carried By SWAT And More

You can also go with a sling and take a leaf out of the US SWAT team’s book and keep it agile for the worst firefights.

This is a favorite weapon, in some form or another, of Law Enforcement and military units all around the world.

Sig Sauer doesn’t make bad weapons. We already know that. Too many police and military units dish out their weapons as standard equipment.

We also know that it had the original HK MP5K, and its successors, firmly in its sights.

Did Sig Improve on Perfection?

Sig Sauer set out to make a better version of this iconic gun that HK simple wasn’t providing at that point.

The end result has been a resounding success. Now the HK SP5K is here to fight for market share, but there’s a big price difference.

The HK is still a thing of beauty. It’s an icon and a welcome addition to any serious collection.

But if you’re going to use your 9mm then you might want to buy the Sig Sauer instead. It’s probably a better gun, for much less money.

We have a big selection of 9mm AR pistols here, if you’re looking for options. Options we’d recommend include the expensive and yet awesome HK SP5K and the much more reasonable CZ Scorpion Evo 3.