Fact or fiction?

[aimless]

1) quite sure: yes
2)???
3)no, the pressure/explosion would take the easier way "out" (thru the barrel), because the pellet is lighter than the piston (disregarding the spring)

ps: to 1) : "using a (very) much heavier pellet"

[magicesperanto]

1) Highly plausible.

2) Highly unlikely.

3) Tosh in my view, if that much force was involved in dieseling, surely the world would be littered with cheapo airguns with exploded chambers?

[johnbaz]

But Larry lamppost said that #3 had happened so he must have first hand knowlege that it's possible


John

[magicesperanto]

But Larry lamppost said that #3 had happened so he must have first hand knowlege that it's possible


John

I can see it being possible with a completely blocked barrel, but a tight/heavy pellet?

[aimless]

#3 IMHO impossible according to the "momentum conservation law" if both ends of the "combustion chamber " are movable and the heavier part (piston) shall move....but I admit, I have to take my calculator now out to calculate with he pressure regarding the area.......

[aimless]

OK:

area of pellet : ( .177) 16 mm² weight: 0,5 g
area of piston: (diameter 30 mm) 706 mm² weight : 253 g

factor of weigth piston/pellet: 506

factor of area piston/pellet: 44

so the bigger area of the piston (model of the combustion chamber , both ends -piston-pellet- open/movable)
can not "overrule" (produce a higher force) the lower weight of the pellet in the first moment of "explosion" . so the piston will not move.

or am I wrong?

please excuse my humble technical english....

[Turnup]

1) Fact.

2) While it is possible to visually identify spring damage, I find it hard to accept that the damage is characteristic of one cause only. Also note that dieseling can be caused with light pellets, so how can you tell?


3) Fact from personal experience. In my youth. cautiously experimenting with deliberate dieseling using a Webly pistol. I found that, while it clearly increases MV, it greatly reduces accuracy. I stopped my experiments when the gun re-cocked. OK it does not take much to re-cock an old wobbly Webly pistol spring, but it surely did happen.

To the posters who reason that a light pellet will give way before a heavy piston, note that compression tube pressures act equally in all directions, and that the larger area of the piston will will therefore cause the piston to experience more force than the pellet. Also the pressure in the barrel will in fact be lower since there is restriction in flow at the breech, and also possible sonic shockwaves there too. It is clear that even without dieseling, piston rebound can occur (many of the tuners on here will attest to that) - the rest is a matter of extent.

[shabee]

1. fact.
2. fact in so much that there probably will be an airgun smith that makes this claim, but entirely fiction in reality, there could be no way of knowing that a heavy pellet had actually caused the damage, any dieseling caused by a heavy pellet in a marginal gun would be insignificant, and only very mild, and unlikely to cause any damage.
3. fact.
eric