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Posted: Mon Jul 07, 2008 10:19 pm
by Hotwired
There are interesting similarities between the recorded rated fitting failures logged around here.
My personal theory has been that if a barrel on an over-under is at all free from the chamber then on firing (even with no ammo) the upward flexing and leverage of the barrel can put excessive stress on the over-under bend.
PVC being a brittle plastic as it is doesn't seem to get along well with being under tension from the air pressure and then being stretched that bit more.
Posted: Mon Jul 07, 2008 10:55 pm
by willarddaniels
I am glad you got it all figured out- and foremost, I am glad you are okay and no bodily harm came of this.
Posted: Tue Jul 08, 2008 12:14 am
by daxspudder
well I think I have discovered a valuable lesson, that I have never heard of. Keep your barrels supported on over unders. My replacement chamber is going to be an inline, so hopefully that will help.
Posted: Tue Jul 08, 2008 1:08 am
by THUNDERLORD
daxspudder wrote:well I think I have discovered a valuable lesson, that I have never heard of. Keep your barrels supported on over unders. My replacement chamber is going to be an inline, so hopefully that will help.
A support between the chamber and barrel still won't hurt on inlines, to take stress off valve connections.
Been thinking of watergun designs... I definately don't plan to shoot water pushed by pneumatic at someone directly.
Or use any type of metal nozzle that could come loose.

8)
Posted: Tue Jul 08, 2008 1:49 pm
by jimmy101
daxspudder wrote:well I think I have discovered a valuable lesson, that I have never heard of. Keep your barrels supported on over unders. My replacement chamber is going to be an inline, so hopefully that will help.
The Wiki mentions the need for adequate barrel support for over/under configurations (
here). And it has been discussed in various spudfiles forums many times.
It is a good idea to spend time thinking about the stresses on any homemade construction. If the construct actually moves the stresses may well be completely different than when the construct is just sitting there.
Posted: Wed Jul 09, 2008 8:15 pm
by daxspudder
THUNDERLORD wrote:daxspudder wrote:well I think I have discovered a valuable lesson, that I have never heard of. Keep your barrels supported on over unders. My replacement chamber is going to be an inline, so hopefully that will help.
A support between the chamber and barrel still won't hurt on inlines, to take stress off valve connections.
Been thinking of watergun designs...
I definately don't plan to shoot water pushed by pneumatic at someone directly.
Or use any type of metal nozzle that could come loose.

8)
Actually my two year old and all my neighbors kids love it. They even beg for it, they love to shoot it as well, with me holding it of course. Ive been shot from as close as 10 feet @ 80psi, it hurts but I dont shoot anyone at less than 30', cause that far the cold of the water stings more than the pressure...
not to mention nothing is more fun than shooting 3-15 kids at once with a potato gun...(that'll make a good sig...

)