Gun physics question?

[Walkalong]

I had NO working space bar.

lol, gotta do what ya gottta do.

 

[jski]

The reasoning behind the experiment of using a 150gr. cast bullet for my .30 Carbine Blackhawk was what I've read about Paco Kelly's "long range carbine load" (courtesy of John Goins):

He was loading the old Lyman 311440 bullet in the .30 Carbine case for the Ruger Blackhawk. He called it his long range carbine load. Since I owned a couple of the 311440 moulds, I quickly became interested and ran out a few hundred 311440s. To successfully shoot this load, you need to achieve a velocity of 1200 FPS or the bullet won’t stabilize. This was clearly stated in his article and in my efforts to duplicate his load, I found out that it was gospel….almost to the last FPS.

To begin with, I was shooting a stock .30 Carbine Ruger. I have an idea his had been throated a bit but no mention was made in his article. My gun wouldn’t allow me to seat the bullet very far out and I ran into problems almost immediately in the form of pressure. I tried his loads of 2400 and after conferring with Felix, I tried N110. Forget 4227 as I couldn’t get enough in the case. The 2400 loads worked; however, pressure caused sticky extraction and I didn’t want that for sure. The loads shot accurately but it seemed as if I was at a dead end. Oh well, I’ll shoot the 311440s in the .30/30.

I'll be using Hodgdon's H110 in lieu of N110.

 

[Archie]

Archie, for umpteen years I've been told that the reason the .30 Carbine Blackhawk has such a loud report and blazing flash is unburned powder burning when the bullet exits the barrel. Even though my .357 has just as loud a report and blazing a flash.

I believe you without question, JSki. I'm sure you have. I've heard very serious and confident people tell me all manner of nonsense for umpteen years. I was going to cite some examples, like 'racing slicks (tires) only work on special tracks' but never mind.

The .30 Carbine cartridge in general is loud - even in a carbine - because it is a high pressure round and the pressure is still high when the bullet leaves the barrel. Shoot a .308 Winchester or .30-06 Springfield round from an eighteen inch barrel and see if they don't ring your chimes.

As Walkalong said, muzzle flash comes from burnt particles - superheated from the chamber pressure - reacting with oxygen in the air. More pressure equals more heat, so a higher pressure release (short barrel) will produce more flash. Like your .357 Magnum.

There is at least one report on the internet about muzzle flash, generated from a report by the U. S. Navy regarding large guns. I don't remember the location, but it's probably one already mentioned.