I'm pretty new to guns, so by no means an expert. Anyway, I have a Cooey 750 single shot that I take shooting, I shoot probably 300-500 rounds of .22LR a week right now. Twice now I have randomly experienced powder and debris blowing back from the reciever. Today I had a round that sounded odd and a whole bunch of debris blew back in my face. I checked the bore and it was good. Anyone know why this happens? It scares me a bit when it happens.
Blow back
- Thread starter FLYBYU44
- Start date
unstableryan
CGN Ultra frequent flyer
- Location
- Beautiful Okanagan Valley
Your barrel might be more like a .20 caliber from so much shooting without cleaning. It makes the pressure skyrocket when the bullet has to squeeze through.
How is your accuracy? How often do you clean it well?
How is your accuracy? How often do you clean it well?
What does your brass look like after being fired? Compared to an unfired round, any bulges? When you turn you bolt handle down/lock the bolt, can you push the bolt ahead at all?
The bolt came out fine and the spent casing actually looked pretty normal, I will have to see if I can push my bolt ahead at all, I don't think so as the action is pretty tight when closing. I clean it every second time I go out, there was a lot of crud in the barrel, but even after ten rounds I can usually see crud lying in the barrel, I thought that was normal. 
Accuracy is pretty decent, I have a 2" gong I can easily hit every shot at 50 yards.
Accuracy is pretty decent, I have a 2" gong I can easily hit every shot at 50 yards.
Cooeys are stiff, they all seem to be...at least the ones I've had/used. (talking bolt closing) In fact, I was using my nephew's 750 this past Monday~dandy gun. Since nobody has asked~what type of ammo were you using? I've found gas/debris "blow back" to very common with Remington-branded rimfire ammo, in Cooey, Norinco, and one Savage .22 I was using. Most recently (last winter) in my immaculately clean Norinco JW15A "Backpacker". Peppered my face with hot, dirty, black debris. My wife said it looked like I had pink freckles~good day to be wearing safety glasses!
I only ever bought Remington when I couldn't find anything else, but that was the last shot I ever took using Remington .22lr, and I'll NEVER use it again.
I only ever bought Remington when I couldn't find anything else, but that was the last shot I ever took using Remington .22lr, and I'll NEVER use it again.
If the round fails to produce enough pressure to obturate and seal you can experience blow back. It's very common with CB cartridges and I experience it occasionally with crappy bulk ammo.You said it sounded off so I'd wager that is the cause.
Any possibility your firing pin is splitting or cutting the rim and that is causing the blow back.
Sometime the hole is so small or in such a position as to not be noticeable.
Older brass can sometimes become brittle and more prone to splitting.
The two makes with which I had the above happen was some CIL Mark III(40 to 50 years old), and Lapua Silhouette that was over 20 years old.
Sometime the hole is so small or in such a position as to not be noticeable.
Older brass can sometimes become brittle and more prone to splitting.
The two makes with which I had the above happen was some CIL Mark III(40 to 50 years old), and Lapua Silhouette that was over 20 years old.
I thought of that and held the casings up to the sun to see if I could see anything, could not see any light. I have noticed that there is burn marks up the casing a ways. That happens with all my cases except Federal which looks like brand new when it comes out. Anyway I cleaned her up really good today, the barrel was pretty dirty. Also checked the bolt, I can't move it at all when it's locked in firing position, very solid. I will shoot the rest of the Winchester ammo in my BL22 since it has the receiver around the bolt, less chance of it happening again.
