Disassembly and Reassembly Of the Sig Sauer P250 Pistol

What happens when a car gets designed by a committee? Answer: The Edsel. So does it follow that a gun-design committee would produce a pistol with innards resembling a Rube Goldberg mousetrap? It might, except that the P250 was designed by a committee consisting of Messrs. Thomela, Metzger, and Mayerl of J. P. Sauer & Sohn of Germany, assisted by Ethan Lessard, lead designer for Sig Sauer, Inc., of Exeter, New Hampshire, where the P250 is manufactured.

And I can assure you, this collaboration definitely did not result in a handgun like the ill-fated Ford. On the contrary, the pistol design they produced may one day be considered as significant as John M. Browning’s design of the immortal M1911. Like other Sig pistols, the P250 is a short-recoil, locked-breech semi-auto with a cam-operated barrel that locks into the slide’s ejection port. And like other Sig pistols, the P250 also has a polymer grip frame. But that’s where the similarities end.

The grip frame of the P250 serves merely as a "dust cover" for the gun’s steel receiver unit. And the receiver unit (where the serial number of the gun is located) is the big breakthrough. This unit fits inside the grip frame, includes the rails on which the slide rides and the entire firing mechanism, and the receiver unit is secured to the frame by the takedown lever’s axis pin. This frame-within-a-frame idea has shown up on more than one pistol of overseas design.

As regular readers of this publication may recall, I’ve written articles on the disassembly and reassembly of a few other examples, causing me to arrive at this conclusion: The sole reason for placing a frame-within-a-frame is to make a gunsmith’s job 100 times more difficult. And the complex manufacture of these pistols ensures that the prices will be high. But, again, the P250 is different. This frame-within-a-frame design— while not exactly inexpensive—is definitely not complex.

The Sig P250’s steel receiver is like the chassis of a GM concept car I read about in a magazine a few years ago. With that concept car, a number of different body styles and sizes could be bolted onto the same chassis. As I understood it, a young couple could begin their married life with a compact or convertible body, and later have a full-size sedan or even a station wagon body dropped onto the chassis as their family grew.

The steel receiver of the P250 is much like that automobile chassis, and it’s the key element that results in this handgun’s amazing versatility. The polymer grip frame (or "dust cover") comes in full, compact, and

sub-compact sizes. Each of these overall sizes are available in wide, medium or slim models to accommodate different hand sizes. Grip frames for the 9mm, .357 Sig, and .40 S&W versions are interchangeable. (Due to the size of the .45 ACP cartridge, it requires a separate grip frame that will not interchange with the smaller-caliber frames.) As you might expect, a proper slide/barrel assembly and magazine are required when changing calibers, but the same steel receiver serves all.

For example, a 9mm slide/barrel assembly can be slipped out of the grip frame and into a .357 Sig, .40 S&Wor .45 ACP grip frame and secured with the takedown lever. It takes less than a minute to make the switch, with no tools required. Are you beginning to see what I mean about the versatility of the P250? Well, hold on; there’s more to come. Suppose the 9mm P250 was originally purchased for concealed carry in its sub-compact, slim configuration.

Then some day down the road the owner decides he needs more "punch." All he has to do is buy a slide/barrel assembly and magazine in, say, .357 Sig or .40 S&W, field strip the pistol, and reassemble it with the new components. Conversely, if the same owner decides he’d feel safer with the stopping power of the .45 ACP, he doesn’t have to purchase a whole new Sig P250. By buying a full-size grip frame, a .45caliber slide/barrel assembly, and a magazine, his yearning for greater stopping power has been achieved.

Yet, he still hasn’t given up the gun’s concealability. The smaller-caliber sub-compact components are still intact. It will take less than 60 seconds to put them back into their concealcarry mode. Another example of the clear and thorough thinking by the gun’s design team was their concern for shooters with small hands and/or short fingers. To that end, the team designed two triggers for the steel receiver.

One is for the majority of shooters, while the second sets the trigger farther to the rear in the guard—in effect shortening the length of pull. Combine this second trigger with the narrow grip frame and any problems of proper feel or comfort in small

Sig Sauer Model P250 Semi-Automatic Pistol (Specifications subject to change without notice) 1 Polymer Grip Frame 2 Magazine Catch 3 Magazine Catch Stop 4 Magazine Catch Spring 5 Takedown Lever 6 O-Ring 7 Steel Receiver (frame) 8 Slide Catch Lever hands are likely to vanish. Field Stripping Plus Remove the magazine, put on your eye protection, and lock the slide open with the slide-catch lever. Then inspect the chamber for the presence of alive round.

Rotate the take-down lever clockwise until it’s brought to a halt by the stop incorporated in the 9 Slide Catch Lever Spring 10 Slide Catch Lever Pin 11 Trigger Bar Spring 12 Trigger Bar 13 Trigger 14 Hammer 15 Hammer Pivot Pin 16 Hammer Strut Pin grip frame. Retract the slide a little to disengage the catch lever. Control the slide movement forward and off the grip frame. Next, invert the slide.

Push the recoil-spring guide forward slightly, lift its rear, and remove it along with the spring to the back end of the slide.

Then lift the rear of the barrel and remove it to the rear. 18 Small Mainspring 19 Large Mainspring 20 Safety Lever 21 Barrel 22 Recoil Spring Guide 23 Recoil Spring 24 Slide 25 Front Sight 26 Rear Sight 27 Safety Lock 28 Rear Extractor Spring Guide 29 Extractor 30 Firing Pin 31 Firing Pin Spring 32 Safety Lock Spring 33 Spring Pin 34 Extractor Spring 35 Front Extractor Spring Guide 36 Magazine Tube 37 Magazine Follower 38 Magazine Spring 39 Magazine Insert 40 Magazine Floorplate Remove the take-down lever by turning and pulling on it simultaneously.

Push the steel receiver assembly forward to clear its locking tab from its mating slot in the grip frame. Pull up on the receiver rails while drawing the hammer partially to the rear, and rotate the receiver upward and out. This is a bit farther than the P250

Modify a pin punch (per instructions in the text) in order to drift it upwards from the slide. owner’s manual says to go, but getting the receiver separated from the polymer frame lessens the chance of damaging the finish of the pistol with a harsh solvent, while giving ample access to the receiver for a good scrubbing away of fouling with something like good old Hoppes #9. Don’t overlubricate the P250, and wipe off any excess lubricant before reassembly. Detailed Disassembly Begin by inverting the slide.

About an inch from its rear you’ll find what looks like half a pin (see photo). It’s actually a whole roll pin. The only way to get it out is to grind or file a flat on one side of a punch, and then use the punch to drift the pin out to the top of the slide. Press down on the safety lock (#27) to remove the firing pin (#30) and spring (#31). I’ve noticed something previously with Sig Sauer schematics. The drawings lead you to believe that the firing-pin assembly seats in the barrel chamber. No way.

It’s inside the slide. (I wish the manufacturer would have the drawing corrected.) Press in on the rear extractor-spring guide (#28) to release the rear-sight assembly (#26). Withdraw the guide. The extractor spring (#34) and front spring guide (#35) usually come out with it. If not, you can fish them out with a dental pick. The extractor (#29) gets lifted away with tweezers. Sometimes it will depart the slide on its own if the slide is turned right-side up and tapped upon a bench top.

Give the steel receiver (#7) a closer The unidentified pin is the trigger stud, which is drifted left to right. look. You were expecting it to be complicated? So was I. Instead, it looks as if there aren’t enough parts to it to make it work. But work it does, and very well. I found this to be a pleasant surprise, especially after having examined a few other foreigndesigned frame-within-a-frame pistols. I suspect that lead designer Lassard of Exeter, New Hampshire, had much to do with the simplicity of this design.

As you hold the unit between the fingers of both hands, with the serial number facing away from you, there’s no missing the four pins on the left side. Three of these are headed (#16, #15, and #10). Drifting is done from right to left. The pin you see under #10 isn’t a pin. It’s a stud permanently attached to the trigger (#13). Turn the unit to its opposite side. The other end of the stud I just mentioned is also a permanent part of the trigger in the form of a tab.

This tab has a small stud of its own that snaps into the front end of the trigger bar (#12). While on the subject of #12, a few minutes spent examining how its spring (#11) is attached to the safety lever (#20) and the back of the bar are in order. The hook end of the spring engages the lever, the opposite end is inserted in the bar, and the coil is supposed to ride beneath the 90-degree bend at the

rear of the bar. To see how the trigger/bar/spring combination works, press in lightly on the bar above its rear spring hole, pull the trigger a little to the rear, and release it a few times. Now turn the unit hammer-side down, grab a magnifying glass, and focus on what you see under pin #16. This pin is identified as the hammer-strut pin. How odd. There is no hammer strut in the P250. What you’re looking at inside the hammer under the pin are the small and large mainsprings (#18 and 19).

If you’re wondering why I haven’t mentioned drifting any pins out by now, the mainsprings are why. You don’t want to do any drifting until you’ve ground or filed a notch in a blade screwdriver that spans leaves enough meat on the blade to reach and depress the combined mainsprings. This takes all the pressure off the pin and allows you to remove it. These springs are strong, however, and will come flying out of the hammer if you forget to keep control of the springs with your forked driver blade.

Okay, drift out the hammer pin far enough to free the safety lever. Follow that with removal of the catch-lever pin. Both pins move right to left. Use the previously modified punch to get the catch-lever pin moving to avoid any interference from the tab connecting the trigger to the trigger bar. Be careful about the lever pin. It’s all that holds the lever (#8) and lever spring (#9) to the receiver. This brings me to the trigger and its close relatives.

Unlike the other pins you’ve encountered in the P250, the trigger stud is drifted left to right. Before you start on it, squeeze the front of the trigger bar tightly against the side of the receiver. This avoids the danger of bending the bar when you drift the stud. The tab will get detached from the bar in this process A special tool must be made to depress the springs before removing or reinstalling the pin. and the trigger can be removed.

Since you previously removed the safety lever when you partially withdrew the hammer pin, pull the pin all out and remove the hammer. Hopefully, the lever will have remained attached to the trigger bar. This reduces the risk of damage to the spring when separating it from the lever and bar. Reassembly Tip I started the reassembly with the hammer and safety lever.

After inverting the receiver, the twin mainsprings are placed in the hammer and depressed with the homemade tool until the hammer-strut pin can be pushed through to retain them. Doing this first stabilizes the back end of the receiver, making the balance of reassembly simply a "reverse order" operation. Oh, and don’t forget to pull the hammer back when returning the receiver to the polymer frame. This moves the trigger to the rear and allows it to enter the guard. There you have it, ladies and gentlemen.

I haven’t seen a firearm as simple or more versatile as this one since I got my first look at the inner workings of a Benelli semi-auto shotgun. Enjoy the experience. ■