The Marksman Repeater doesn't use a C02 Cartridge it a spring operated pistol
Please ask your question again. No one makes a 2 gram air cartridge. I think you are asking about a 12 gram C02 cartridge. CROSMAN never made a model 1107. Check your pistol again
Most all C02 air guns use the common 12 gram C02 cartrage.
Most of the time it lasts for 85-100 shots around a months use if you fire it every day.
There is No C02 cartridge in the Marksman Repeater, it is spring operated
Take the left plastic grip off the gun. It should pop off. Remove the old C02 bottle (You may have to unscrew the bottom screw a little. ) Replace the C02 with a new 12 gram C02 bottle. Then using a coin screw the bottom screw in until it stops. This will charge the gun with new C02.
It should stay cocked. The gun has problems. But, it's such a cheap pistol I wouldn't even try to fix it. Just buy a good C02 pistol, or something that will last you a long time.
You go to a sports store and purchase one.
I've had this happen to a few of my C02 guns. Remove the cover. Unscrew the pressure plate under the C02 cartridge. Rapp the bottom of the pistol butt with your hand. It's going to take a few times but it will come lose. You can also try pushing down with your thumb between strikes. A few things to remember when you go to put a new C02 cartridge in. Purchase "Crosman Pellgun oil." DO NOT USE regular oil it will damage the seals. Put a drop of oil on the end of the 12 gram cartridge before you put it in the handle. It will lubricate the seals and help prevent it from sticking in the handle. Never leave a C02 cylinder in the pistol overnight it will eventually blow the seals. Those cylinders produce 800 PSI so it is not good to leave them in the pistol. They only cost about 60 cents each and not worth trying to save. I get about 60 to 80 shots out of my pistols before they run out if C02 then I remove the cylinder when I'm finished. It's also good practice to remove them to prevent someone else from picking up the pistol and discharging it by accident.
There are several factors that effect "HOW LONG" is. Temperature, How fast you pull the trigger. and how long the "powerlett" is in the pistol. It is best to say about 50 or more shots per powerlett. However never leave the C02 in the pistol when you are done. It will eventually leak out and may damage the seal if the pistol stays under pressure. Also it will prevent someone from picking up the pistol and accidentally firing it.
the C02 seal is shot. time to install a new seal. check with customer service at the link below.
If you are asking about the Crosman C02 pellet pistol then Yes that is what it is designed to power the pistol.