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Apollo · Member

Ok, so I bought a new CR1077, never been fired, the box had original factory seals. The serial numbers say it was built in 2004.

The CO2 seal went south so I replaced it. I continued on with the disassembly and did the following ;

Re-crowned the barrel.
Increased the detent's opening using a 5/32 drill bit.
Added the missing o-ring in the detent.
Lightly lubed metal contact and pivot points.

Firing the gun, this is what I observed :
The faster I pull the trigger, the more powerful the shots are. This must be causing the hammer to strike the valve faster/harder.

Where I used to get co2 leak at the magazine clip, this leak is gone.

I now get 48 powerful shots (plinking, not target).

Lastly, and this is what I'd like you opinions on, when I fire the gun with an empty magazine (magazine in place to so all co2 is directed out the barrel), I get a lot of co2 coming out of the muzzle. The puff of co2 gas is visible. More so when compared to one of my other airguns that shoots at 640 fps.

I'm thinking this co2 can be utilized with a longer barrel, giving me higher fps. Anyone got any tips on utilizing this wasted gas?

Also, comparing impact results (I know, not scientific or empirical) of the pellets fired from the 1077 against my other airguns, I'm estimating fps is aroung 400-450 (I don't have a chrony). I don't want to do more mod to get more co2 to push the pellet. Rather, I want to make the gun more efficient.

I welcome any ideas.

Thanks.

broommaster2000 · Moderator

I doubt that your shots get more powerful when you launch them at plinkeroonies in a quick consecutive way. When CO2 expands, and it hugely does when your firing it quickly, it also cools down quickly, thus lowering the pressure resulting in a certain loss of Fps. Neutral

Crosman140 · Senior Member

When you say you get CO2 coming out the muzzle, do you mean liquid dripping? If so, this sounds more like condensation due to the cooling effect mentioned by broom.

If it is gas, this sounds normal that as the gas leaves the barrel, it is sometimes visible.

broommaster2000 · Moderator

I wanna bet on it that it's gas. Mr. Green

AirGunEric · Site Admin

If you have gas pluming out the end of the barrel (not condensation) you are likely closer to the 600fps mark (unless you are shooting in cold weather, that would allow for a gas plume much easier due to the lower Co2 expansion rate, but a plume at 70*F would indicate too much gas, too little barrel as you are thinking.

Will a longer barrel help a 1077 that is shooting out excess Co2 in ambient temperatures of 60-80*? Absolutely. But, I am unaware of any easily available barrel swaps for this with a 1077 so you may be forced to construct one yourself.

Apollo · Member

I'm shooting indoors at room temp, approx 21 degrees celcius.

The fast trigger pull is for single shots and there's definitely more gas plume when I pull the trigger fast.

At least now I know that I'm sending the CO2 down the barrel (as opposed to leaking it through various points in the plumbing). Unfortunately, as Eric stated, I need a longer barrel to make use of the excess CO2.

Maybe I'll just add a muzzle brake.

Slavia · Moderator

I've noticed the "cloud" coming out of my 2240, but only at dusk on a really humid summer day (when the ambient temperature is approaching the dew point).

The only way you'll really know is by shooting through a chronograph. Do you know anyone that has one? (Maybe paintballers?)

Apollo · Member

I've noticed that cloud from my 2240 as well. The amount coming from the 1077 is considerably more.

Like you said, the only way to really tell is by using a chrony.....I'd buy one but I just bought a new 1:6 scale Hummer R/C last night.

oddtodd · Silver Status Member

I get it off both my 2240, and my 2300 custom. I can understand in the 2240, but I have the longest barrel that crosman sells on the 2300. my wife doesn't care much for my 2300 because you can see the plume through the scope because of the muzzle break and the way it is drilled. She says it makes her not be able to see the trget drop.

Jaxom · Senior Member

Darn it, there's gotta be a way to find a longer barrel that can be machined to fit the 1077! UGH!!!!