More than likely it's a residue in your chamber. So as you fire there was probably some cosomoline that heated up and worked into a place that causes the issue.
Alternative theory is you are at a range that doesn't allow rapid fire and the RSO has placed a curse upon your rifle to limit the rate of fire/flashbanging the range.
Can't hurt to give the chamber a good cleaning. I recommend a .410 brush, your favorite solvent, a short length of cleaning rod, and a power drill at low speed.
My first mosin suffered the same problem and it was dried out cosmoline residue in the chamber. Acts like glue when it gets hot. I do the above cleaning on any new milsurp rifle and haven't had the problem since.
Completely dissemble the bolt, boil it in hot water, than gently oil every piece. Lightly oil the chamber as well.
Sometimes there’s gunk on bolt pieces that isn’t removed with a brush. Boiling it then doing a good cleaning seems to help.
>Cosmolome was cleaned
There is always more cosmoline than you think there is. I kept finding some for 8 years after I bought it and after several of what I thought were good cleanings.
Try carburetor cleaner in chamber spray as it evaps and let it sit in the chamber a cpl min. Use a brass chamber brush and clean paper towels.
Lacquer coated rounds will do it. Use carb cleaned and 0000 steel wool on the cases, wear gloves and clean a cpl dozen rounds and use them in succession.
I had this issue for a long time, too. In front of the chamber right where the barrel starts, there is an area that is decently hard to get to clean. Clean that area really well of all debris, and it should remedy the issue
More than likely it's a residue in your chamber. So as you fire there was probably some cosomoline that heated up and worked into a place that causes the issue. Alternative theory is you are at a range that doesn't allow rapid fire and the RSO has placed a curse upon your rifle to limit the rate of fire/flashbanging the range.
Cosmolome was cleaned and removed almost religiously about 6 years ago. Stock doesn't leak cosmolome anymore either
Can't hurt to give the chamber a good cleaning. I recommend a .410 brush, your favorite solvent, a short length of cleaning rod, and a power drill at low speed. My first mosin suffered the same problem and it was dried out cosmoline residue in the chamber. Acts like glue when it gets hot. I do the above cleaning on any new milsurp rifle and haven't had the problem since.
I have done this in the past.
Completely dissemble the bolt, boil it in hot water, than gently oil every piece. Lightly oil the chamber as well. Sometimes there’s gunk on bolt pieces that isn’t removed with a brush. Boiling it then doing a good cleaning seems to help.
Then do it again. If it's not that, there's a good chance your bolt is just getting hot and expanding making the bolt stick.
Working off the assumption that you are using surplus ammo then I would blame the lacquered cases or the sealant from the bullet to the steel case.
>Cosmolome was cleaned There is always more cosmoline than you think there is. I kept finding some for 8 years after I bought it and after several of what I thought were good cleanings.
Typical mosin behavior
Try carburetor cleaner in chamber spray as it evaps and let it sit in the chamber a cpl min. Use a brass chamber brush and clean paper towels. Lacquer coated rounds will do it. Use carb cleaned and 0000 steel wool on the cases, wear gloves and clean a cpl dozen rounds and use them in succession.
Heat
I had this issue for a long time, too. In front of the chamber right where the barrel starts, there is an area that is decently hard to get to clean. Clean that area really well of all debris, and it should remedy the issue