We are looking at shotgun shot shell pressures, not .308 60,000 psi rifle pressures.
10 gauge 11,000
12 gauge 11,500 (except 3-1/2 in.)
12 gauge 3 1/2 in.14,000
16 gauge 11,500
20 Gauge 12,000
28 gauge 12,500
.410 Bore 2 1/2 in. 12,500
.410 Bore 3 in. 13,500
Smokeless powder shot shells operate at considerably lower pressure than most muzzleloaders with black powder. Would bet C&B revolvers with six screw in percussion nipples looking shooter in the eye, operate at same or higher pressure than a modern shotshell generates.
So I guess everyone with a caplock muzzeloader of any sort, better hurry up real quick and throw their barrels into the garbage.
Put in a fudge factor and say the shotgun is operating at 15,000 psi, force is caculated by diameter and the pressure operating on it.
Say the screw is a 8-32 with a diameter of 0.164", just off the top of my head, I calculate the force being exerted on the 8-32 screw is around 1,200 pounds.
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |