Update, October 9, 2026: ATF no longer requires a Form 4, tax stamp, fingerprints or registration for suppressors, short-barreled rifles, short-barreled shotguns or AOWs. They now transfer on a standard Form 4473 with a background check. Anything below that mentions a Form 4, a wait or a tax stamp was written before this change. What changed
⚠ SHORT BARREL RIFLE (SBR) — NO FORM 4 REQUIRED Since October 9, 2026, ATF no longer requires a Form 4, tax stamp, fingerprints or registration for short-barreled rifles. It transfers on a standard Form 4473 with a NICS background check. Your state’s law still applies, and taking one across state lines still needs an approved ATF Form 5320.20. Outside Texas, we ship to an SOT dealer in your state. What changed · How buying one works now
The Maxim Defense MD:9 CQB 9mm 33-Round SBR is the high-capacity configuration of Maxim’s ultra-compact 9mm Short Barrel Rifle — running Glock-compatible 33-round extended magazines for maximum round capacity in a compact CQB platform. 5.5" barrel. Gen. 7 CQB stock. Same SOCOM-grade engineering as the PDX and SDX platforms, applied to the 9mm pistol caliber carbine. Subsonic 9mm with a quality suppressor delivers hearing-safe fire. DLC / Type III hard coat anodized black finish. Military-grade materials. Made in USA. ISO 9001:2015.
Spec
Detail
Caliber
9mm Luger
Barrel Length
5.5"
Magazine Compatibility
Glock 9mm — 33-round extended included
Stock
Gen. 7 CQB Stock
Color
Black
Finish
DLC / Type III hard coat anodized
Materials
7075-T6 & 6061 aluminum + hardened steel
Manufacturer
Maxim Defense Industries — Made in USA — ISO 9001:2015
NFA Class
Short Barrel Rifle — no Form 4 required
MD:9 5.5" vs 5.8": Which to Choose?
Both MD:9 variants use the same CQB stock and run Glock 9mm magazines. The 5.5" model ships with a 33-round extended Glock magazine, giving you maximum capacity in Maxim’s compact package. The 5.8" model ships with a 30-round magazine. Either variant pairs naturally with the Maxim MS-9 9mm suppressor — also available at Western Sport.
Maxim Defense Industries is a Minnesota-based, ISO 9001:2015 certified American firearm manufacturer. Every platform — PDX, SDX, MD:9 — is engineered from military-grade materials and developed alongside the SOCOM PDW solicitation. Maxim Defense builds its firearms from 6Al-4V titanium, 17-4 stainless steel, 7075-T6 and 6061 aluminum. Made in the USA to order.
Frequently Asked Questions
What is an SBR? A Short Barrel Rifle has a rifle barrel under 16″ and is federally regulated under the NFA. BATFE Form 4, background check, $200 NFA tax stamp — now $0 under OBBBA.
How long does NFA approval take? Typically 30–90 days. Western Sport holds the SOT, and since October 9, 2026 there is no Form 4 to file.
Is the $0 NFA tax stamp permanent? The OBBBA eliminated the $200 NFA tax. Western Sport recommends calling to confirm current status.
Does the MD:9 use standard magazines? The Maxim Defense MD:9 is Glock 9mm magazine compatible — runs the same standard-capacity Glock mags you already own.
We file your Form 4 for you. No Form 4 needed.
Ordering from Western Sport
Order online and we ship it to the licensed FFL dealer you choose near you — see how buying a gun online works. Western Sport has been a licensed FFL/SOT dealer since 2007, and everything we sell carries the full manufacturer warranty. Questions before you order? Send us a message.
This item is out of stock. These are on the shelf today and ship or transfer the same way. Not sure which is the right swap? Call 817-393-4000 and we will tell you straight.
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