Smith & Wesson’s Model 4006 and 4006 TSW Pistols

By David Tong

S&W M4006
Photo by David Tong.

In the early 1990's, fairly widespread dissatisfaction with the 9x19mm round and the then available JHP bullets caused the FBI and law enforcement agencies to consider the development of a “10mm Lite” round. This is a watered-down version of the original 10mm Norma cartridge used in the FBI service pistol at the time.

The original Norma loading was a 200 grain bullet traveling nearly 1,200 fps. Further ballistic testing by the FBI caused a re-think about the needlessly (for self defense against humans, anyway) powerful round, which intimidated non-shooter Agents and beat up their pistols. The resulting Lite round propelled a 180 grain pill at approximately 950 fps. This now subsonic round did not make efficient use of the long Norma case. It was surmised that if one simply reduced the length of the case to 20mm, one could have a 9mm-size handgun that would be more easily wielded that the bulky 10mm pistols. In addition, the desire to have a higher capacity magazine than the eight rounds of the M1076 was considered vital. By shortening the case, it allowed the use of essentially the same butt section and magazine body stamping of the 9mm pistol already in production.

Smith & Wesson was the first to manufacture pistols for the new cartridge, not coincidentally named .40 S&W. (Also ".40 Small & Weak." -Editor.) The cartridge was designed by Winchester and debuted in January 1988.

The Model 4006 .40 pistol is a strengthened version of the 9mm Model 5906. It was introduced on January 17, 1990 and adopted by the California Highway Patrol shortly thereafter. It has a heavier slide, with more steel on the top, as well as the recoil spring seat area. The frame has a much thicker dust cover area and the recoil spring guide area has substantially thicker web support. The dust cover’s slide rail guides have been relocated and thickened to preclude installing the .40's slide onto a 9mm pistol. One last observation is that the barrel’s wall thickness adjacent to the chamber appears fairly thin, betraying its 9mm origins.

Altogether, these changes made an already heavy pistol heavier. I know of no other handguns so extensively strengthened to accommodate the .40 round. (Perhaps most competing 9mm pistols were more durable to start with. -Editor.)


  • Type: Semi-automatic pistol
  • Action: Browning type short recoil
  • Overall Length: 7 ½”
  • Height: 5 ½”
  • Barrel Length: 4”
  • Weight, Empty:
  • Sights: Steel S&W click adjustable for windage and elevation with protective ears; steel dovetailed front sight; 3 sighting dots
  • Trigger: Double-action first shot 12lbs; single action 4 ½ lbs follow up shots
  • Trigger guard: Slightly extended, round, non-checkered and reinforced
  • Magazine Capacity: 10 or 11 rounds depending on state legality
  • Safeties: Internal magazine disconnect; spring loaded ambidextrous decocking levers, no manual safety; firing pin plunger lock

The CHP pistol was used until roughly 2007. By most accounts it was well-received, though some complained about the weight, or the non-adjustable ergonomics. Several active and retired officers have commented on its durability and said that the agency has retained several training pistols which have had in excess of 100,000 rounds fired through them.

Due to the agency’s long-standing relationship with S&W, it put out a no-compete bid for a very similar pistol in 2006. Called the 4006 TSW, “TSW” stood for Tactical Smith & Wesson, but the CHP pistol differed from the commercially available version in one major way. The commercial TSW had a black anodized aluminum rail riveted onto a slightly modified dust cover ahead of the trigger guard. The CHP pistol has an integrally machined rail that made the pistol’s frame forging a unique one and drove up the acquisition cost significantly.

A rail system on police service pistols is nearly mandatory at this time (2011). It assists the officer in identifying a criminal suspect in a low light situation. The attached flashlight could help the cop both more accurately place the shots, as well as reduce the possibility of misidentification of the suspect. (Turning on a light, of course, makes the officer a prime target for any other shooters in the vicinity. -Editor.) The issue lamp is said to be the Streamlight TLR-1. Current duty pistols have a “CHP” serial number prefix.

The ambidextrous levers now act as decockers only and are spring loaded to return to the fire position. A minor change was a cost saving move. The trigger and hammer are manufactured using the metal injection molding (MIM) process, instead of the machined-from-forgings method used on earlier production Third Generation pistols.

CHP may be the last large LE department that is still using a fully steel constructed service pistol. This is sad, because there are stories illustrating the shooting difference between the most prevalent plastic-framed .40 and the 4006. CHP officers shooting the plastic framed pistol said that the recoil was “surprisingly sharp, but not unmanageable,” while polymer-equipped officers from another agency commented on the 4006's recoil feeling more like a push than a snap.

My father-in-law is not an experienced pistol shooter, but he commented that the 180 grain ball rounds were a bit easier to control than 230 grain ball out of his .45ACP SiG P-220, which is also a half-pound lighter.

As everyone knows, accurate hits are essential in any armed encounter and an equal-caliber pistol that is easy to control with softer recoil, so much the better. While the bore center is taller than that of a Glock or 1911, the weight helps control muzzle flip. In addition, the short resetting trigger aids in the accurate and rapid second or third shot with the relatively mild muzzle rise and recoil pulse.

The pistol shows its age in one significant aspect besides its weight. That is its rather limited magazine capacity of 11 rounds. Even compact versions of the plastic competition carry 13 rounds, so S&W made an engineering choice over two decades ago and stuck with the smallish round count. The .40 magazines have a raised bump on their front spine, to preclude their use in the similar 9mm pistol.

I found both the double and single action trigger pulls of the 4006 to be significantly smoother and lighter than that of a recently tested M5906. The DA stroke felt at least a pound lighter. Likewise the SA hammer drop. The pull is approximately 4-½ lbs, crisp with no overtravel. Not bad for a bone-stock service pistol these days.

In addition, CHP administrators did away with the hammer spur and reduced the weight of that part. This reduces the impact against the firing pin and very slightly reduces the lock time, although the intention was to prevent thumb cocking. It is an attempt to reduce negligent discharges by inadequately trained officers.

CHP and S&W have had a seventy-year long plus relationship, and while no doubt many line officers would like something lighter to carry, there are no official plans to replace the over 7,500 4006 TSW's in service. Just as well. The first .40 caliber service pistol in the world is still on duty, and the cartridge is now used by over 70% of all American LE departments. Why change when something works?

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Copyright 2011, 2016 by David Tong and/or All rights reserved.