Crosman 1077 pressure consistency issue?

[xiholdtruex]

Hello everyone,

I have a crosman1077 which seems to be giving me issue. I have had it for 2 years. Has only about 500 pellets ( two 250 cans ) through it. I have a issue that when I load a co2 canister and shoot sometimes I will get 12 extremly weak shots or it will not even have enough pressure to push the pellet out of the magazine. I have 4 different little speed cylinders and they all seem to do it. I use pel oil on the tip of every other co2 cylinder. it does not seem to be leaking co2. I have tried waiting 30 secs between shots and no difference. I have tried tightning down the co2 screw all the way down and backing it off a bit also. The pierce on the co2 is clean and the correct size. I am in south florida and the temp has been around 78 - 90 lately and have been shooting in the shade.

could it be a valve issue? could I have a bad batch of co2 cylinders, have had them now for about a year and a half



Thanks in advance and advice is appreciated

 

[marflow]

I would think if the valve had a problem it would be a leaking problem but this rifle has the co2 travel by a delivery tube so to speak and the power could be lost with leaks down valve

here is parts diagram

https://www.dropbox.com/s/w21h6akerxdwy6l/Crosman_C1077-2.pdf

co2 cartridges are more then likely fine

from what I have read chancing down the leak point can be a challenge

unless the spring powering the hammer has failed or come out of place

I always want to get one of these and screw around with it but the more I read the less I'm interested

good luck not much help, just a guessing game

 

[xiholdtruex]

I would think if the valve had a problem it would be a leaking problem but this rifle has the co2 travel by a delivery tube so to speak and the power could be lost with leaks down valve

here is parts diagram

https://www.dropbox.com/s/w21h6akerxdwy6l/Crosman_C1077-2.pdf

co2 cartridges are more then likely fine

from what I have read chancing down the leak point can be a challenge

unless the spring powering the hammer has failed or come out of place

I always want to get one of these and screw around with it but the more I read the less I'm interested

good luck not much help, just a guessing game

took it apart tonight to take a look inside. cross referenced a diassembly guide which had pictures of a working 1077. all parts looked good. reassembled going to test it out tommorow. got a new pack of co2 ran out of the old pack. lets see how it works will update.

 

[John "spysir" Blount]

Fla. @90 degrees would likely be an issue with that model. Even an over spring QB78 can lock up ( low or no power shots) around 90 and your rig is built much more as a lower power plinker. Noted you mentioned varying temps, any chance of indoor testing? Fun rifles tho, gave one to a 70ish year old neighbor and he put 1,000 pellets through it in a week, good fun. If you like Co2 and haven't tried a QB78/79/other you can pick one up on sale at a box store (synthetic version normally) for under $80.00. Lot's easier to work on than the 1077 so you'd be a natural at all the DIY mod's folks do.



John

 

[xiholdtruex]

Fla. @90 degrees would likely be an issue with that model. Even an over spring QB78 can lock up ( low or no power shots) around 90 and your rig is built much more as a lower power plinker. Noted you mentioned varying temps, any chance of indoor testing? Fun rifles tho, gave one to a 70ish year old neighbor and he put 1,000 pellets through it in a week, good fun. If you like Co2 and haven't tried a QB78/79/other you can pick one up on sale at a box store (synthetic version normally) for under $80.00. Lot's easier to work on than the 1077 so you'd be a natural at all the DIY mod's folks do.



John

Tried the 1077 in the house it was 72 degrees. Same issue no power just barley shooting the pellets out the barrel. I guess it is time to replace the 1077 lol I do not think I will go co2 for the time being due to how hot it has been down here. Those qb78s look veru nice. I think I will either pick up a crosman fx4 or a crosman 1377 to playwith. Have a whole carton of .177 wadcutters calling to me lol. The benjamin prowler has been keeping me busy in the mean time.