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Stemple Takedown Gun (STG) U9 Slow Fire (SF) - Adjustable Bolt System


Product Description

U9 Slow Fire (SF) - Adjustable Bolt System

The Slow Fire (SF) utilizes an ultra-smooth adjustable-weight bolt system with hydraulic buffering to dissipate the energy in the recoiling mass during the cycle process.  This is an ideal system for shooters looking to maximize suppressor performance by increasing dwell time in the chamber thereby reducing port noise. The cyclic rates with this system are adjustable between 525 to 900 round per minute.  Shooters can customize their preferred rates simply by adjusting the bolt parts.  At the lowest rate, this gun has a sustained fire of approximately 9 seconds with a 70-rd drum.   The Heavy Bolt System is also used for the 45ACP and 7.62x25. These setups utilize AR pattern stocks, AR pattern grips, and multiple Picatinny mount options for maximum versatility.  

This gun is also ideal for use with a suppressor. The extra bolt weigh drastically slows the initial bolt blow-back thereby significantly reducing port noise common in open-bolt  blow-back SMGs.


In 2003, the original inventor, John Stemple collaborated with BRP Corp to make new and replacement parts for the Stemple 76/45 receivers he manufactured prior to the 1986 cutoff.  From this came a series of compatible drop-on parts for the unmodified/transferable Stemple 76/45 receivers known as Stemple Takedown Gun (STG) setups.  Since nothing is welded or hand fitted to these receivers, changing setups and replacing parts is fast and easy.  These are the most finely built and smooth running sub-machine guns on the transferable market.  We build them for performance and durability, stock plenty of high-quality spare parts, and provide excellent service.  There is only a limited number of these pre-1986 registered/transferable machine guns remaining, so get one while they last.


Parts and Accessories Included With Each Gun:  foregrip, bipod, 2 drums, 1 magazine, multi-tool, spare buffer, barrel locknut/muzzle cap tool, choice of barrel and shroud setup  (sights not included) 


If you are going to buy a transferable machine gun for some serious shooting, you should consider the Stemple Takedown Guns for these reasons:

They are ‘new’

Well, the receivers are nearly 30 years old but the Stemple Takedown Gun (STG) setups are complete new parts packages installed on unused pre-1986 transferable Stemple 76/45 machine gun receivers.

Simple / Durable Design

Our guns are very difficult to break and very easy to fix. They are simple blow-back guns and very smooth-running in long full-auto bursts. Some of our customers who own the 9mm guns liken the full-auto performance to a laser beam.


By using Picatinny rails (MIL-STD-1913) for sights and hand guards, shooters can add a variety of accessories and optics.   The configurations with the Adjustable Bolt System use common AR pattern stocks and grips with hundreds of options currently available. 

Easy-to-Replace Parts

There’s nothing on these guns that can’t be easily replaced.  We designed this system to protect the registered receiver from any wear during use.  The only parts that can wear can be easily replaced without the need to ship the gun back and forth.

Available Service

If you need service, we are here to support our products.

Shoot Cheap Ammo

We typically just shoot steel-cased ammo. Our milled steel trunions easily deal with potential wear issues from any type of ammo.

Capacity and Control

These guns use 70 round drums and are smooth cycling, heavy, accurate, and comfortable to hold.  It's basically an assault rifle with a sub-caliber setup... a very controllable and accurate gun in full auto.  It's so smooth due to the weight, layout, and action; you can actually watch your target being hit through a 4x scope while shooting long bursts.  The 'laser beam' performance of this gun makes is one of the most enjoyable full auto guns you'll ever shoot.

Can't Get Too Hot

These are ideal for machine-gun shoots. The low-pressure pistol ammo cannot create enough heat in the barrel to cause a malfunction or damage the gun.  There's no gas system to clog, and the open-bolt system negates any cook-off risk.



U9 (SF) Data:

Select-Fire with Quick-Change Barrel

Ultra-smooth adjustable-weight bolt system with hydraulic buffering 

Cycle Rate: 550-800 adjustable 

Magazine: Suomi KP31 25 rd, 36 rd, 50 rd magazines and 40 rd & 70 rd drums

Nickel Boron Plated Bolt

Weight: 9.3 lbs

Stainless Steel Barrel

Barrel Length: 10.35" threaded .578-28 to use common suppressor


Spade Grip Setups Also Available:  http://www.brpguns.com/stemple-stg-spade-grip-kit/

Linkup with our other customers via our Stemple STG Facebook Group:  https://www.facebook.com/groups/110088872841613/




Add-on Items:

STG U Series Case: Custom routed HD foam instert designed to fit the U9, U9 Slow Fire & U45

Case: $475

Silencer:  $425

Add both for $600




Product Videos

Stemple U9 Slow Fire 5 14 2015 (01:13)
Machine gunner in this video is competitive shooter Emily Nichole. Instagram: Emily_nichole_6
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    Stemple 76/45, U9 Heavy Bolt / Slow Fire setup
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