Ran across this while inspecting my reloads the other day. This is what imminent case head failure looks like. This would have been painful at the very least. Be careful and always check your rounds.
"painfull" . . . . would guess not.
Guessing - - -> Would sound different. Bullet would exit bbl. Bottom half of case would be extracted and ejected. Top half would stay in chamber. Next round would not load and action would stay open.
I believe that the chamber and bolt face would contain any normal (SAAMI) pressure levels. --- SAWMAN
My estimate of painful is based on shooting this in a polymer gun with a potential lack of case support (Glock). May or may not have resulted in injury but I'm glad I caught it prior to firing it.
If you do any reloading for an mount of time you will learn all about case separation, and happens. The worst thing you can happen is a barrel obstruction, now that can be a bad day, jUst my 5 cents jj
In some pistol caliber firearms the chambers are not fully supported and some are more unsupported then others as a compromise to feed ramp angle and reliability. Pressure will always take the path of least resistance first and a case seperation will cause hot gasses to escape around the bolt face and down the unsupport chamber area towards the mag well. It is not the same level as a double charge/ wrong powder type Kaboom but you can get burns (more so on pistols with removable grips).