Even while the field trials of the Colt 1907 were ongoing, John Browning was improving his pistol. With the Model 1909 he designed the single-link barrel system that would prove to be the core of the final 1911 design. The 1909 model also included an enlarged grip safety, a slide release integrated with the barrel link pin, a new magazine release button that could be operated with one hand, and the firing pin retention plate. It wasn’t quite sufficient, however, and was closely followed by the Model 1910.

It was in the 1910 that Colt and Browning revised the grip angle from the quite square 1900/1902/1905/1907/1909 style to the more steely angled pattern we recognize form the 1911. The 1910 model also added the internal extractor, combined the mainsprings into a single three-finger piece, and improved the ejector. It would be modified to also include a thumb safety, to allow safe reholstering. The first major test of the 1910 against the Savage .45 took place on November 10, 1910, and while the Colt/Browning pistol was the better of the two, it had 15 malfunctions and four broken parts in the 6,000 round endurance test. Neither it nor the Savage were deemed acceptable, and a second test was scheduled for March 15, 1911.

It was in that March of 1911 test that the Colt/Browning passed the endurance test with no failures of any kind - a very remarkable achievement. The Savage was still suffering significant problems, and Colt was declared the winner, with the pistol to be adopted as the Model of 1911.