Pressure inside a Gun Barrel 2

Results from PRODAS 2000 interior ballistics analysis:

7.62mm M80 82MPa
50cal M8 124MPa
30mm PGU14 36MPa
105mm M735 16MPa

These are all peak values within the barrel. The last one is interesting, since the pressure is so much lower, but the round is so much heavier that it has a muzzle velocity of 1500m/s. The M735 is an armor-piercing fin-stabilized, discarding sabot round from the 1st generation M1 Abrams tank. The 30mm armor piercing round is from the 30mm cannon used on A-10 Warthog.

TTFN

I'm afraid I'm going to have to disagree with IRstuff on this one. You must have erroneous data. My recent experience with design of APFSDS rounds suggests that the data for at least the last round on your list (M735) is most certainly inaccurate. To give an idea, the M833 (105mm APFSDS) round hattains an exit velocity of 1,494 m/s and experiences a base pressure of ~448MPa. Taking into account the projectile's mass of approx 6.2kg and the mass of propellant (5.8kg), the actual peak pressure experienced by the chamber/breech would be in the order of 658MPa.
For this reason, the data for the 30mm PGU14 round seems rather unlikely also.

grampi1, if you can get access to Jane's Ammunition Handbook (online or in hardcopy) you will prob find more info than you ever wanted to know.

cheers

Sory, you're right. I was reading the wrong tables.

The sim shows peak breech pressure of 432 MPa, peak base pressure of 280 MPa.

PGU14, max breech 371 MPa, max base 365 MPa.

.50 cal, max breech 369 MPa, max base 362 MPa

7.62 mm, max breech 352 MPa, max base 345 MPa.

TTFN