Yes, if the round has proppery been brought into battery, the firearm holds the ability to discharge without the magazine in place.
The M11 is the Sig Sauer P228, for which a 13 round magazine is standard. It can also accept 15 or 20 round magazines common to the Sig Sauer P226.
The button on the back of the slide of a SIG Sauer P250 is the slide release lever. It allows the shooter to manually release the slide after inserting a magazine or when clearing the firearm. Pressing this button enables the slide to move forward and chamber a round, facilitating quick operation and reloading.
10 rounds
Best left to a trained professional
The dimensions of a SIG Sauer P226 20-round magazine typically measure approximately 5.4 inches in height, 1.3 inches in width, and 0.9 inches in depth. However, specific measurements can slightly vary based on the manufacturing processes and materials used. Always refer to the manufacturer's specifications for the most accurate details.
No, they are two very different models in terms of magazine size.
Best left to a trained armorer
Best left to a gunsmith or SIG trained armorer
12-20 rounds depending on caliber and magazine.
Yes, as long as it is made specifically for the P229/P228.
Try gun shows, gun shops, Brownell's, e-gunparts.com
Sig Sauer P229 and P239 chambered in .40 S&W. Here's the press release from Sig.