Quote Originally Posted by Leonardj View Post
When mild dieseling occurs, some of the excess lubricant is slowly burned off, but the chamber temperature does not reach the point of ignition, and the resulting detonation. This mild dieseling slowly eliminates the excess lube so that when the mild dieseling settles after a few heavy pellets, there is insufficient "fuel" for detonation to occurr, when switching back to the lighter pellets.

Consider the theory that with the heavy pellet, the piston begins to slow sooner than with the lighter pellet, thus actually building the pressure more slowly against the added restriction. Slower compression, would result in lower chamber temperature, and thus less tendency to diesel.
Thus, the gun that is achieving detonation with a lighter pellet, the piston is moving faster, and further, compressing the air far more quickly - faster compression of air = higher temperatures = detonation.

If I understand you correctly, you use of the term "mild dieseling" means "evaporated by heat and pressure changes", without ignition?

And you use the term detonation to mean ignition of the fuel within the compression tube?

Is this generally accepted airgun terminology? What bothers me is that in a diesel engine the fuel/air mixture is ignited by the temperature rise due to compression. The fuel mixture deflagrates (burns) but does not detonate. Detonation is a different phenomenon and in engines is not desired. NB it is quite difficult to induce detonation with oil as a fuel, this is exactly why diesel engines run on oil rather than petrol, which detonates more easily.

I really do not see that enhanced evaporation/vaporisation of oil within an airgun, arising from the temperature/pressure changes, can in any way be called dieseling.

Really don't get this. With both a heavy and light pellet, the piston begins to slow before the pellet has moved.

Don't get this either, the lightest possible pellet (i.e. no pellet) leads to the highest pressures and temperatures?