SIG Sauer P6
SIG Sauer P225
History:
In the late 1960’s the Swiss Armed Forces were looking for a replacement for their venerable SIG P210 9mm sidearm. The SIG 210 is a great pistol but the methods used to manufacture it were making it very expensive to produce. The Swiss wanted something cheaper but still needed something that was able to perform well. They preferred a weapon having a double action/single action trigger mechanism. The P220, which was adopted in 1975 by the Swiss Army as the A75, was designed for the Swiss as an easier to manufacture replacement for their famed SIG P210. The P6/P225 is basically a compact version of the SIG P220.
The Swiss manufacturing consortium SIG (Schweizerische Industrie Gesellschaft) won the bid but they did not have the manufacturing capacity immediately at hand. So SIG teamed up with JP Sauer and Sohn and in 1975, the Swiss Army adopted the 9mm SIG-Sauer P220, which was designated the A75 by the Swiss Army. At about the same time, after reviewing the performance of their .32 cal Walther PP, the German police forces decided that they needed a little more gun. They specified a 9mm pistol that was 180 mm (length) and 130 mm (height). They also required some features that made the pistol drop safe and had some way to prevent accidental discharge. They also wanted a visible indicator to show if the pistol had been dropped on it's hammer. Three German companies responded to their specifications; Walther, with the P5, SIG-Sauer with the P6 and Heckler & Koch with the P7. German states could purchase whatever they wanted but most chose the P6 as the new manufacturing techniques made it the cheapest of the lot. The P6 was the most widely issued sidearm to the police in Europe, with over half a million having been made. The Swiss Police, among others, used the P225. P225's were also offered on the open market in the US and other countries.
It is relatively easy now to make a compact 9mm pistol but at the time the German Police specifications were considered rather demanding.
Acoording to the Cybershooters website
Note: this is still a problem with some sub-compacts, I have seen some instruction manuals that recommend changing out the recoil springs at as low a figure as 200 rounds. A friend of mine has a popular compact pistol whose latest recoil spring lasted a mere 275 rounds. My P225 spring has had thousands or rounds through it and there is no sign of failure.The problem with most compact 9mms of the time was that after a few hundred rounds, the recoil spring simply collapsed, having been "screwed" too tight. So how did SIG manage to achieve the engineering feat of making such a compact 9mm pistol? Well, quite simply they used a braided recoil spring. The braided spring used by SIG-Sauer prevents this from happening, and allowed them to chop the necessary 2cm off the front of the P220 to make the P225. It's not as elegant as the dual-spring arrangement in the Walther P5 or the retarded gas recoil system of the H&K P7, but it works - and it's a hell of a lot cheaper to manufacture!
Sometime in the mid-2000's the German police forces decided to update their pistols. They declared a large number of P6's as surplus and these were bought by US arms importers. At first these P6's flooded the US used pistol market and were sold at rock bottom prices. As the numbers of pistols have decreased, prices have gone up quite a bit.
Function:
There were many innovative features used in the manufacture of the P220. One standard method of making a delayed blowback pistol in the day was to use the Browning delayed blowback type of action. This consisted of cutouts having to be machined in the top of the slide with matching lugs in the top of the barrel. This locked the two assemblies together till the swinging link (like the Colt 1911) under the barrel caused the barrel to pivot downwards, unlocking the mechanism. This kept the mechanism locked till the pressure decreased to a safe limit. Once unlocked the slide was free to travel rearwards, eject the empty casing and load a new cartridge from the magazine. The continued forward motion of the slide then locked the barrel and slide together again.
A 1911 barrel showing the grooves milled in the top and the swinging link at the bottom.
Image from here
image from Here
A P220 barrel. Note that the feed ramp is part of the barrel and there are no barrel cutouts and there is no swinging link. The SIG P series pistols lock the back of the barrel against a replaceable machined steel breech-block that is pinned into the slide. At the time relatively few pistols used this method but SIG perfected it. Today many manufacturers use this method of locking the barrel including the ubiquitous Glock. When the barrel unlocks, it tips up similar to the 1911 pistol.
The first pull of the trigger is a double action pull. This long heavier pull helps act as a safety mechanism agains inadvertent discharge. Once the gun has fired, ejected the empty cartridge and loaded a new one, it is ready to fire with a less heavy single action pull. You can also decock the pistol at this time and it will revert back to the double action pull.
Specifications
Operation Semiautomatic, mechanically locked, recoil operated
Trigger Double-action/single-action or double-action only
Safety Patented automatic firing-pin lock
Caliber 9mm Luger
Length, overall 7.1"
Height, overall 5.2"
Width, overall 1.3"
Barrel length 3.9"
Rifling twist 1 in 10"
Rifling grooves 6
Sight radius 5.7"
Weight, w/o magazine 26.1 oz.
Weight, empty magazine 2.8 oz.
Trigger pull DA 12 lbs., SA 4.5 lbs.
Magazine capacity 8 rounds
Construction
SIG made these handguns much simpler to manufacture. The top of the chamber locks into the back of the ejection port against a metal breechblock (that is pinned into the slide). This method has become very popular now and it is much emulated. There is also a decocking lever, not a new idea but not used that many times before. The slides were folded out of a piece of heavy gauge sheet metal with the nose-piece being welded on. This welding is done so well that it is impossible to tell from the outside. Some flats and cocking serration were then milled onto the slide, along with the cutouts for the sights. This hugely minimized the number of machining operations required and kept the cost down. While we generally think of sheet metal as being flimsy, there is nothing flimsy about a SIG folded slide. There will probably be a frame failure before a slide failure. A spring loaded automatic firing pin safety was also incorporated into the design. All the controls are stamped out of sheet metal. The P220 in its original form had a heel mounted magazine release and so did some early P225's. New P Series pistols have the magazine release in the now conventional place behind the trigger guard. None of these ideas were really new but SIG amalgamated them into one package. The P220 was rugged, very reliable and accurate. The P6/P225 is basically a cut down P220. A replaceable steel drop-in "locking insert" sits over the trigger assembly.
As CNC machines are cheaper and easier to use today, the slides on today's SIG-Sauer’s P series handguns are machined from a single block of solid stainless steel, however, all P6/P225's have the folded slide. Some SIG purists claim that the stainless slide makes the pistol nose heavy and that the folded slide pistols are more balanced.
The Difference
A P6 (front) and a P225 (rear).
Here you can clearly see the notched hammer of the P6 and the solid hammer on the P225.
The P6 is marked as such and also is stamped with the initials of the state police force it belonged to. The P225 just says P225 on the right hand side of the slide and has the serial number on it.
From a distance, the two pistols are identical. They use the same Anodized Aluminum frame and the same slide. The P6, however has a notched hammer that is noticeably different from the solid hammer used by the P225.
One can also easily tell a P6 from a P225 by its markings. The P6 is marked with the serial number, model number, the initials of the state where it was used and the date of manufacture on the right side of the slide. Both guns had serial number marked on the frame, slide and barrel. Internally, the P6 has a heavier hammer spring. This hammer spring can be replaced with a P225 spring to make the P6’s trigger pull weights identical to the P225. Various finishes were used on the P225 slides including SIG’s proprietary “Nitron” finish. Some P6’s slides just don't seem to be finished as well (?). The P6 usually had plain black combat sights while the P225’s were available with many variations including tritium night sights. SIG offers several front and rear sight options in different heights. Both front and rear sights are drift-adjustable for windage. In other words, the P6 is a P225 with modifications as specified by the German police.
The Action
The action is of a double action/single action (DA/SA) type. The initial pull is long and heavy but once the slide recoils and re-cocks the hammer, the single action pull is short and lighter. The longer and heavier double action pull eliminates the need for a manual safety. If the pistol is to be re-holstered, the decocking lever can safely lower the hammer.
Trigger:
A P6 has a heavier double action pull than the P225. The P6’s DA pull takes about twelve pounds to actuate and the SA pull is four to five pounds. The P225 requires about eight pounds and four pounds of trigger pressure for its DA/SA mechanism. The hammer can also be cocked manually to bypass the heavier DA pull. Both triggers are usually very smooth and the reset on the trigger is easily felt even if it isn’t the shortest reset. Optional short triggers and short reset triggers are available. Changing the hammer spring will change the pull weight. If you put a P225 hammer spring into a P6, it will have the same pull weight as the P225
Safety Features:
Firing pin safety: The firing pin is locked in place by spring loaded metal piece that fits a cutout machined in the pin. Until the trigger is pulled all the way back, moving this metal piece out of the way, the firing pin cannot move.
Half-cock notch. There is a half-cock notch or hammer drop safety that catches the hammer if it were to fall. This prevents inadvertent contact between the hammer and firing pin.
The Controls:
1. Trigger - formed out of sheet metal
2. Take down lever - formed out of sheet metal (lever only)
3. Decocker - formed out of sheet metal
4. Slide release lever - formed out of sheet metal
5. Hammer - machined from solid metal
Take down:
Among semi-auto pistols, the SIG P series have one of the most straightforward methods of takedown that there is.
1. Remove Magazine. The P6/P225 magazine is an eight round single-stack magazine. Note, some early p225’s had a heel release for the magazine instead of the now standard button aft of the trigger guard.
2. Cycle the slide back,while pushing up on the slide release lever, till it locks back. The slide will also lock back automatically when racked back over an empty magazine.
3. Turn the takedown lever 90 degrees clockwise.
ERROR: Arrow 1 is actually pointing to the decocking lever. The slide lock lever is the one that is right behind it.
4. Grip the slide and release the slide stop. The slide assembly will glide off the frame.
5. Remove the recoil spring and its spring guide
6. Remove the barrel assembly
Reassembly is the reverse of the above procedure.
Further disassembly is not needed. The gun can be cleaned quite well at this stage.
Magazine take down:
While holding your thumb over the exposed floor plate insert piece, slide the floorplate off. This will prevent the spring and floor plate insert from launching itself across the room.
The disassembled magazine
Complete Take down:
The grips are held on with two screws on each side. After taking the grips off, you will see:
Almost completely stripped except for the decocking lever and it's spring, hammer assy. and the breech-block pinned in the slide. The breech-block contains the firing pin, firing pin safety and the extractor.
Comments and personal observations:
The P6 was the most widely issued sidearm to the police in Europe, with over half a million having been made. This is a service pistol and not a target pistol but they are capable of fine accuracy, more than enough for combat distances. The P6/P225 is considered by many to be the most ergonomic of the SIG P-series pistols. Some people with larger than average hands have complained about their trigger fingers being pinched in the trigger guard. However, the slightly elongated trigger guard allows easy insertion of a gloved finger.
Note how slim the frame of the P6 is. For me, having small hands, it fits perfectly and it is easy to conceal. The slide adds a little more width to it. The alloy frame and single stack magazine makes it light so it can be carried all day with little fatigue.
Some internet sources have claimed that the P6 has a different feed ramp on the barrel and in the late 1980's SIG changed the geometry to match the P225's feed ramp. I've always been a little skeptical of this claim as it seem unlikely that a manufacturer would make two almost identical pistols (in the same factory) with different barrels. My 1979 SIG P6 has fed any ammo that i have loaded into it. It is one of the few pistols that i have that has never malfunctioned. Many other 1979 P6 owners have made similar claims. I have never heard of a P225 failing to feed JHP ammo. However, lending some credence to the feed ramp change theory is the fact that there are quite a few P6's that will only feed FMJ and will choke on JHP ammo. So maybe, as unlikely as it seems, there were several feed ramp changes over the years.
I don't think I will ever sell either my P6 or my P225 and it seems that most of the people who have P6's are holding on to them. After shooting it for a while, it just seems to fit my hand better than anything else out there. It is also big enough for me to get all my fingers wrapped around the grip. I have a real hard time with sub-compact pistols that only allow a two fingered grip.
References and additional media:
How typical SIG P-Series pistols function:
(the site shows a double stack magazine but the function should be the same as a single stack)
http://www.cybershooters.org/general.htm
Other reviews:
http://www.hipowersandhandguns.com/Crit ... 20P225.htm
Operators manual for the SIG P225:
http://sigsauer.com/upFiles/CmsContent/ ... ropped.pdf
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