Solventless nitroglycerine powders

Nitroglycerine powders can be classified into two groups with and without a volatile solvent. Semi-colloidal nitrocellulose powders and nitroglycerine solventless powders are the most important types of smokeless powder. 

Solventless powder without nitroglycerine (G powder, p. 660) has a lower heat of explosion, and consequently causes less wear on the bore. 

Powder with a low content of nitroglycerine is simply called solventless powder to distinguish it from ballistite. 

Solventless powder is usually tubular. It was first produced at the Diineberg factory, in 1912, under the name of RPC/12 (Rohrenpulver mit Centralit 1912). Initially the manufacture of this powder was based upon the use of easily soluble nitrocellulose (11 % N), plus guncotton to bring the total nitrogen content up to 11.7%. About 25% nitroglycerine was used plus a large quantity of centralite (4-5%) as a non-volatile solvent. 

In the U.S.S.R. a type of solventless powder was introduced in which organic nitro compounds, e.g. DNT, partly replaced the nitroglycerine. DNT acts as a non-volatile solvent and as a stabilizer. Since it also reduces the heat of explosion these powders are either flashless or partly so. 

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