Thread: The Importance of Using the Right Data

Originally Posted by Moa Hunter

What you write re proof powders / loads may very well be correct, but I hazard it is a guess. How do we know what powders and loads are used ? Perhaps common powders are used. It would be useful to me if pressure was always quoted in load data so that I knew how close to 65,000 I was. Certainly some load data does quote pressure. I thought O'Conner used IMR4831 not H, anyway I dont really like 2213, just used it as an example.

Greetings Moa Hunter,
IMR4831 was not offered to the public until the early 1970's. The original powder, although made by Dupont, was clearly slower and some comparative tests have shown this. Originally called just 4831 the H prefix was added when IMR4831 appeared. O'Connor developed his loads. In a letter to Ken Waters in the mid 1960,s O'Connor referred to the powder as No4831, clearly the Hodgdon offering. The Hodgdon/ ADI quotes pressure either in CUP or PSI for almost all their load data, one reason why I prefer it.
Regards Grandpamac.