When you happen to drop one as I did once!!! Picked a SA Colt up by the holster and did not notice the hammer wasn't secured and it slid out. The guns hammer was in that faux safe position over a loaded chamber. Being as how nothing broke and it landed butt first, the jar of hitting the hard floor must have made the hammer bounce out of the so called safety notch and fire the gun. No damage, no injury, but lesson learned. AND, if the hammer is down on a primer or firing pin, modern or cap, a blow to the hammer will fire the gun quite easily. In the case of a real Colt and most copies, a hard blow to the hammer can easily break the thin hardened sear tip and fire the gun if it is fully loaded. Even if in the so called safety notch position on a Colt SA model P and any other gun that depends on a similar arrangement such as old model Ruger SA's. It is not a difficult job to drill holes for pins on a typical C&B Colt copy that does not have the pins. I have 2 ASM Colt C&B types that did not have them. Oddly, the hammers had the little receptacles for the pins but the cylinders were not pinned nor drilled for them. Just for the record, I hate guns with transfer bars, handgun or rifle, but I can live with 5 rds loaded rather than 6 to be safe. If you know trouble is imminent you can always put #6 in if you think you may need it.