The modern low-wall's are a different design from the originals. The modern low-wall has the receiver shoulders, behind the breech block, at or above the center line of the bore. This design change has more effect than the metallurgy.

The original low-wall has the shoulders significantly below the center line of the bore. This works like a post in a post hole. Fairly easy to crush the dirt at the top of the hole with a side load on the post.

The chart shown is a cropped version of the original. Cropped information included a caution about other effects than cartridge thrust, my name and date. The chart is based on SAAMI data to attempt to quantify the capabilities of an original low-wall. .357 Mag. was the largest cartridge found in print and knew of a cracked low-wall in .32-40.

My greatest concern with the chart was the mixing of more modern transducer pressure measurements with older Copper Units of Pressure (CUP), but did not see a choice.
Chuck

The modern low-wall's are a different design from the originals. The modern low-wall has the receiver shoulders, behind the breech block, at or above the center line of the bore. This design change has more effect than the metallurgy.

The original low-wall has the shoulders significantly below the center line of the bore. This works like a post in a post hole. Fairly easy to crush the dirt at the top of the hole with a side load on the post.

The chart shown is a cropped version of the original. Cropped information included a caution about other effects than cartridge thrust, my name and date. The chart is based on SAAMI data to attempt to quantify the capabilities of an original low-wall. .357 Mag. was the largest cartridge found in print and knew of a cracked low-wall in .32-40.

My greatest concern with the chart was the mixing of more modern transducer pressure measurements with older Copper Units of Pressure (CUP), but did not see a choice.
Chuck