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
Maxim Defense PDX SBR — .300 BLK 5.5" — FDE
The Maxim Defense PDX .300 BLK FDE SBR is RECOIL Magazine’s “Best of SHOT 2019” PDX platform in FDE Cerakote, chambered in .300 Blackout — the optimal caliber for suppressed short-barrel use. Born from the SOCOM PDW solicitation, the PDX delivers maximum lethality in the smallest package: 18.75" overall length, 5 lbs 11 oz, HATEBRAKE™ muzzle booster, and Maxim’s SCW™ stock system. .300 BLK with a 5.5" SBR barrel — add a can to the HATEBRAKE™ for hearing-safe suppressed fire with 220gr+ subsonic loads. FDE Cerakote. Hard anodized. 6Al-4V titanium, 17-4 stainless steel. Made in USA. ISO 9001:2015.
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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