Home Forums Reloading Big Game Rifles Dupont PB vs. IMR PB?

Got a deal on 3 lbs of Dupont PB, the only load data I'm finding is for IMR PB. Are they close to the same burn rate?

They're the same thing.

Thanks, MD. This tickles me.

IIRC, Dupont PB always came in 8oz. cans and was more per pound than the rifle powders. Hope you actually got 3 lbs. and not 3 cans.

You're right, just checked. Good thing it was $4 per can.

Still a terrific deal. I burn it in .38 Special, 9mmm Luger, and shotshells. It flows through your powder measure almost as well as ball powders.

Dupont owns IMR. Same Same.

Not for a long time.

But the powder should be about the same...

Forrest

Not since about 1918 or so. Government broke em up in anti-trust suit.

Not quite.

DuPont bought control of their major competitor, Laflin & Rand, in 1902; previously they had purchased several smaller powder companies. As stated, with an anti-trust action against DuPont, the company was divided. A new company, Hercules, was awarded the Laflin & Rand patents for double-base powders, and DuPont continued to make single-base powders.

Before WWI, DuPont made several powders of a type called Military Rifle or "MR" powders. During WWI some additives in the powder resulted in types they called Improved Military Rifle or "IMR" powders. In 1993, at about the same time that they sold Remington, DuPont sold their powder-making division. The IMR Powder Company was established in Plattsburgh, NY, to continue the distribution of the DuPont powders. Hodgdon bought the IMR company about 2002 or 2003.

PB was introduced in the 1950s as a replacement for MX powder.

Sharpe's Complete Guide to Handloading has a moderately detailed history of gun powder manufacture in the US. Judged by Sharpe's book and other sources, the history of IMR described on the IMR website has several inaccuracies.

--Bob