Pressure in a 12 GA or other unhardened gun

[jpw062]

I am looking at light singleshot 357 Max options for hunting.
I would really like something with an internal hammer or striker. Tang safety would be nice. Looks similar to a Wincheste 37.
On thing that would be pretty easily done would be to, well, basically reline a single shot shotgun to 357 MAX. Inserts are sold that could be epoxied in or a blank could be turned down and inserted. Possibly re-barrel to avoid filling the .
357 max is triple the pressure of a 12 GA. I am not sure about the difference in bolt thrust. Similar numbers with other gauges. I know people are shooting higher pressure rounds out of inserts. Is it anywhere close to safe?

A reputable gunsmith would be involved. Trying to avoid the blank stare he has given me when I presented previous ideas...

 

[PapaG]

12 Gauge pressure is around 10K psi up to maybe 12. 357 max is way over 50K, more like four or more times. Frames are often cast iron. I wouldn't do it.

 

[mcb]

Not sure its worth it but you could make it work.

First the pressure for 357 Rem Max* is potentially 4X more than standard 2.75 & 3.00 inch 12 Gauge is 11,000 PSI (3.50 inch 12 Gauge is 14,000 psi). But pressure alone is not super meaningful without looking at other factors like actual dimensions and materials.

First the hoop stress caused by this extra pressure can easily be contained by whatever barrel liner you use to create the rifle 357 Rem Max chambering. There will be more than enough room for plenty of strength.

I have never seen a modern single shot shotgun made from cast iron. Cast steel yes, cast iron never. Cast steel is plenty strong if done right (as Ruger). That said 357 Rem Max is not really putting any more stress on the frame of a single shot than a 12 gauge load will. A 12 Gauge shell at max pressure (11,000 psi) will generate ~5600 lbs of thrust (shell is ~.809 diameter .514 in^2 area) on the breach face. A 357 Rem Max loaded to 48,000 psi will only generate ~5400 lbs of thrust (case is ~.379 diameter .113 in^2 area) on the frame.

So from an engineering point of view with a competent gunsmith to do the work there is no reason it could not be made to work. That said I think you would be better off with a TC Encore in 357 Rem Max

*Is 357 Rem Max a SAAMI cartridge I can't find the spec at SAAMI?

 

[jpw062]

Thanks for the replies. I have done some further investigations and I am considering a custom receiver compatible with the Encore or contender barrels. Possibly a brazed lamination.
Possibly a slightly more difficult to change system such as DW, Savage, or even AR. Looking into possibility of manufacturing a stub compatible with one of those threaded systems and Encore frame.
I had an encore. Ugly and awkward. Bad lines. Bad balance.
357 MAX is no longer listed by SAAMI. The information is available in older printed material.