1911_Hardball
New member
One factor often overlooked is the radius of the firing pin stop. The larger the radius the easier the slide can overcome the resistance of the mainspring due to the contact point being higher on the hammer.
My STI 5" in 9mm was not 100% reliable. Its firing pin stop matched the radius of about any .45 1911 I've ever seen. The one in my Ruger SR1911 9mm had a noticeably larger radius. The STI cycled fine with the Ruger stop in it so a few minutes with the STI stop and a couple different grit stones resolved the issue without messing with any springs.
My STI 5" in 9mm was not 100% reliable. Its firing pin stop matched the radius of about any .45 1911 I've ever seen. The one in my Ruger SR1911 9mm had a noticeably larger radius. The STI cycled fine with the Ruger stop in it so a few minutes with the STI stop and a couple different grit stones resolved the issue without messing with any springs.