Quote Originally Posted by Leonardj View Post
Yes, Dieseling and detonation are generally accepted airgun terminology.

As for your comment regarding deflagration, the definition as taken from Wikipedia:

Deflagration (Lat: de + flagrare, "to burn down") is a term describing subsonic combustion propagating through heat transfer; hot burning material heats the next layer of cold material and ignites it. Most "fire" found in daily life, from flames to explosions, is deflagration.

Therefore, your explanation above with regard to deflagration not meaning the same as detonation, is really quite inaccurate. Ignition of any fuel produces detonation - an explosion due to the rapid burning of that fuel. Without detonation (ignition of the fuel), internal combustion engines would not operate.
No - you cite Wikipedia, which states that deflagration is a subsonic reaction. Had you also checked Wikki on "Detonation" you would have found that it is a similar reaction but which proceeds supersonically. Very much not the same thing at all. Not all explosions are detonations. In respect of detonation, Wikki goes on to state

"In engines and firearms[edit]Unintentional detonation when deflagration is desired is a problem in some devices. In internal combustion engines it is called engine knocking or pinging or pinking, and it causes a loss of power and excessive heating of certain components. In firearms, it may cause catastrophic and potentially lethal failure."

Thus when I fire my centrefire rifle, there is an explosion but no detonation (thankfully).

Some materials can exhibit both reaction types depending upon the circumstances e.g. Dynamite will burn steadily and unspectacularly if set fire to, but will detonate if initiated by an appropriate shockwave. The chemical reactions and products (including the amount of energy released) are exactly the same, only the speed is different. Some materials will not detonate, but do explode, for example Black Powder (the stuff Muzzle Loaders use), which is "low explosive" and will self-confine (go "bang" rather than "wuff" when ignited in a loose pile) in quantities of around a pound, but has never been demonstrated to detonate.

You also state "Ignition of any fuel produces detonation" - when I ignite petrol in my cigarette lighter, there is no detonation, no explosion, only deflagration (burning) of a fuel/air mixture.

Dieseling is ignition of a fuel/air mixture by compression effects and in a diesel engine (and for the most part in an airgun) is an explosive deflagration reaction. Detonation inside an airgun is a much more destructive event, and probably quite difficult to achieve with oil as a fuel, but I am prepared to accept that it can happen.