Frame cracking in semi-auto pistols, how common, problem?

[His lordship.]

I hear about frame cracking in semi-automatic pistols from time to time, more so in heavily used Model 1911's used by competitive shooters years ago.  How common is this problem, and if there is a small crack noted, how much further can a person shoot their pistol without problems?

I haved read of Star, Spanish made guns, having an intentional machining process done to allow for a controlled crack, has anyone heard of this?

Thanks.

[John Traveler]

I've seen three cracked pistol frames in a WWII Browning HP, and two Spanish guns:  A Star Model B 9mm Parabellum, and an Astra .380 Constable.  Both cracked at the bottom of the recoil spring tunnel on the frame, from slide impacts.  Stories of "soft" Spanish gun steel are around, and after suffering two broken firing pins, and extractor in these pistols, plus the frame cracking I can believe it.  Both were fired only a few hundred times with factory US ammo.

The Browning High Power was a Belgian late WWII production, and suffered from slide locking lug setback and a cracked frame around the slide stop pin.  It appeared to have been fired extensively, but also showed soft steel.

You should stop shooting immediately if you discover a frame crack.  It might be repaired using MIG of TIG welding, but the work must be done by a highly qualified person.

As for preventing spread of a crack after it starts, it's common practice to drill a hole at the end of the crack to relieve stress.  This was actually done by some shotgun makers at the end of a milled slot to prevent frame cracking.
 
HTH
John