Crow, after doing a "H-335 muzzle flash" google search, I found a post from a gent that called Hodgdon to ask about the known muzzle flash with H-335.
Here was his reply:
H-335,Blc and and BLc-2 as you probably know are double based ball powders. That is, they have a certain precentage of nitroglycerine added to give more power and as an added feature, better storage abilities. One of the byproducts of the high nitro content in H-335 is the generation of hydrogen gas. Depending on the cartridge it could be lots of hydrogen gas. Now when the round is fired as long as that hydrogen gas is contained in the barrel, nothing happens. But when the bullet exits, that hydrogen gas literally explodes in a very bright flash and extremely loud report.
I used to load H-335 in a Remington Model 660 with 20" barrel. In the middle of a Nevada summer at just about high noon, my buddy and I were shooting at tin cans and other targets of oppotunity. I broke out the .308 and torched off a round. The blast was something else but the 4 foot wide ball of fire was actually brighter than the sun. That's when I got interested and gave Hodgden a call asking about it.
I had a small amount left over from all those years ago and used it in my .35 Whelen. It's a darn good powder for that cartridge and I'll have to get more on my next powder run.
Last edited by Sportsdad60; 10/24/17.
