These fit unmodified M1911 pistols.
Break In
Although we have put an M1911 in each holster and closed the flap, the holsters are still not broken in. Holsters are like new leather shoes, not slippers- the pistol won't just fall in- it needs to be shoved in the first few times. Breaking them in is simple- take the pistol in and out several times, and twist it around a bit. Or, just leave it in the holster for a few days. It will loosen up.
WARNING!
There are dozens, perhaps hundreds, of methods posted on the internet about how best to break in holsters. Many are utterly insane. Some involve hot water, oil, heating vents, and household appliances. We recommend nothing other than working the weapon into the holster by hand! Holsters damaged or destroyed due to break-in attempts gone wrong are not returnable.

M1911
What else fits in these?
These holsters were designed and made for the US military M1911 .45 automatic pistol. These are NOT made for the .45 revolver! If you have turned your M1911 into some kind of "tactical operator zombie smoker" by adding scope rails, laser sights or who knows what to the frame or barrel it won't fit in these holsters.
Also, this is not a "universal-will-form-to-fit any .45 caliber pistol". It's leather, not latex.