psi of 303 brit with bp?

[nekshot]

I have been searching for psi of 303 with bp and can find none. Plenty of velocity info but no pressure info. Any factual info around this scholarly society of the Black?
nekshot

[nekshot]

Ok, lets try this another way. Any one know of a formula I can use to decide psi or thrust of a 303 (or any cartridge) with black powder?
nekshot

[EDG]

Thrust of case against the bolt face can be calculated as follows. This method ignores any friction between the case walls and the chamber.

Section a case and find the inside diameter of the case at the base.
Calculate the area then multiply the number of square inches X the pressure of the load in PSI.

[nekshot]

EDG, thanks for your reply. I do have a formula similar to that but I need the pressure amount and I can not find info on black powder pressure. With all the interest in bp and having gone to the moon and back you would think this would be old hat for engineers of which I am not!
nekshot

[Baja_Traveler]

OK, off topic in relation to the question, but I was always under the impression that BP performed very poorly in a necked case. Why the interest in BP 303 Brits? (though it would be fun to show up to a military bolt silhouette match with my Mosin and BP cartridges)...

[dromia]

19 tons per square inch, higher pressure than the cordite round that followed it.

[nekshot]

dromia, thank you for that info.
nekshot

[PS Paul]

Hmmmm. Actually sounds like A LOT of fun, if you can get 'er working?

PS P

[nekshot]

regretfully the pressure is exceeding my standard I set of 15000psi for a double rifle I built out of a double barrel shotgun. I originally thought I someday would try bp in it but I will be happy with what does work, and less cleaning to boot.

[MT Chambers]

The problem that I had with BP in the .303 Br. was that my sights could not accommodate the big difference in trajectory, the side mounted peep sight(Providence Tool) would not get close to the height I needed so I abandoned that project.

[Littlewolf]

OK what would a good load in a #4mk1 manufacturing date 1944 be I have the 308291 and the 311414 mold. I've known the 303 was originally a BP for some time but never found data to give it a go. What would a standard/ish load be boolit, powder charge, filler, primer, and all that.

[junkbug]

Dromia is almost certainly quoting the pressure for the black powder military cartridge, This was loaded with a compressed pellet of 70 grains (I believe). and inserted into the case before the neck and shoulder were formed. That process was continued with the cordite loadings.

Many have tried to duplicate that load, but it is very difficult without heavy factory grade tooling. I may be wrong about the 70 grains, but it is very difficult to get the original factory ballistics using black powder and hobby grade reloading tools.

[MT Chambers]

They both have it right, throw in the fact that Bp makes esp. the British made Bp was superior in power to anything we have today.