Hi all, a friend of mine has a umarex 850 air magnum. When he fires it the pellet does not leave the barrel. Does anyone have any idea what to look at to repair this? Also any idea where I can find a strip down guide? Cheers!!
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the Daily hi thread
Umarex 850 repair/re seal help
- Thread starter Lenny
- Start date
Neil54
Member Extraordinaire
First make sure the barrel is clear.
These are easy work on.
There is an exploded diagram on the Web somewhere, I'll have a look.
These are easy work on.
There is an exploded diagram on the Web somewhere, I'll have a look.
marflow
Super member
the system is easy to understand CO2 direct to the valve the valve stem is hit by the hammer the CO2 released down the barrel
now the rifle can be dry fired a stupid way of saying without a pellet and the rifle should make noise
if not then i would say the something is blocking the hammer from hitting the valve stem hard enough to open it
these rifle have had a long history of pellets being pulled back into the area behind the valve and that would be guess
if it is not leaking you need no seals
are the valves easy to get off the gun that would be a big no you will need help, extra hands
are the valves easy to open that would be no again
once you open the valves do they like to leak and make you chase you tail and waste money on CO2 and that would be yes
would i work on one of these using a 88-90gr cartridge NOT ON YOUR LIFE you need a 2 x 12gr adapter
so this is the world of guess on most forums the hammer is not hitting the valve hard enough if CO2 is present in the system
could the clam shells be taken apart with gas in the system i see no reason why not
i wish you all the luck i have been a 850 owner of 2 rifles for over 10 years
mike in the states
now the rifle can be dry fired a stupid way of saying without a pellet and the rifle should make noise
if not then i would say the something is blocking the hammer from hitting the valve stem hard enough to open it
these rifle have had a long history of pellets being pulled back into the area behind the valve and that would be guess
if it is not leaking you need no seals
are the valves easy to get off the gun that would be a big no you will need help, extra hands
are the valves easy to open that would be no again
once you open the valves do they like to leak and make you chase you tail and waste money on CO2 and that would be yes
would i work on one of these using a 88-90gr cartridge NOT ON YOUR LIFE you need a 2 x 12gr adapter
so this is the world of guess on most forums the hammer is not hitting the valve hard enough if CO2 is present in the system
could the clam shells be taken apart with gas in the system i see no reason why not
i wish you all the luck i have been a 850 owner of 2 rifles for over 10 years
mike in the states
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Hi You seem to know your onions I had an 850 running very nicely on an 850 psi reg bottle, but had to push it didn't I,,,, have an air tube this has a 1000 psi reg gun fires once then no more air comes through on cocking, can't fathom co2 has more Welly than 1000 psi surely
marflow
Super member
in your case it could be the hammer spring will not open the valve
when The 850 Forum was up and running the owner of the forum was also a maker of 850 rifles in HPA and a heavy hammer spring was always used and the increase in power 50fps that was it
to me it seemed a waste of time but those who tinker, tinker of course this was when there were far fewer PCP offerings
if you use HPA you install a Walther Dominator 1250 hammer spring
when The 850 Forum was up and running the owner of the forum was also a maker of 850 rifles in HPA and a heavy hammer spring was always used and the increase in power 50fps that was it
to me it seemed a waste of time but those who tinker, tinker of course this was when there were far fewer PCP offerings
if you use HPA you install a Walther Dominator 1250 hammer spring
Thanks for reply and info it was fine on a 850 spring so shall return to that, found one tutorial on the magnum and compared to a springer frightened me to death.
marflow
Super member
the higher-pressure level from CO2 to HPA in the 850 was known to hold the valve closed and the factory 850 spring could not overcome, that hence the stronger spring out of the Walther 1250
now the Walther spring was also used for more power as it would hold the valve open just a bit longer
i would think if the CO2 were to get to a high temp the hammer would also fail to open the valve but that is an assumption
now the Walther spring was also used for more power as it would hold the valve open just a bit longer
i would think if the CO2 were to get to a high temp the hammer would also fail to open the valve but that is an assumption
Thanks for reply I've ordered new 850 reg and will live with that, the new dominator spring isn't expensive but as said feels a very complex replacement compared to say replacing a spring in my springer, and with my luck would take the conversion into the land of naughtyness.
marflow
Super member
just some picture i have save from others
you will notice in the bottom picture the owner added a roll pin for a better trigger fell on the front of the trigger
once the cover is off the parts stay put and the long spring in the middle back is the hammer spring as you would think
you will notice in the bottom picture the owner added a roll pin for a better trigger fell on the front of the trigger
once the cover is off the parts stay put and the long spring in the middle back is the hammer spring as you would think