I'm not sure if it's the gun or the ammo. I'm leaning toward ammunition, but I'd like a few other opinions.
The ammo is CCI Blazer - the supposedly 'good' stuff that's sold in the 50-round boxes, not the bulk packs. The rifle is a Cooey Model 39. The gun is relatively new to me, and I've only put about 200 through it so far.
I recently noticed that the gun occasionally 'vents' some gas back at me: I can feel it fit my wrist and cheek. It seems to occur with one out of every 5 or 10 shots, but only when firing the Blazer ammo. I haven't noticed any issues with other ammo (mostly M-22) that I've fired. I looked at a handful of spent cases and it's pretty clear which ones caused the problem. The cases appear to have split open along the rim, and I suspect that some gas escapes and flows backward along the bolt channel and out at the shooter.
This is the ammo:

Here, you can see the scorch marks on the bolt face near the firing pin. It also looks like some gas gets channelled out of the extractor slot.


If you look closely (hopefully you can see it in the photos) you can see the split in the rim. The two in the front are the suspect ones. The three in the back are fine, and didn't 'vent'.


So, the question remains: is this an ammo problem or is it the gun?
I really like the gun, and I bought the ammo (Canadian Tire, last year) thinking that it was decent stuff.
Any help is appreciated. Thanks!
The ammo is CCI Blazer - the supposedly 'good' stuff that's sold in the 50-round boxes, not the bulk packs. The rifle is a Cooey Model 39. The gun is relatively new to me, and I've only put about 200 through it so far.
I recently noticed that the gun occasionally 'vents' some gas back at me: I can feel it fit my wrist and cheek. It seems to occur with one out of every 5 or 10 shots, but only when firing the Blazer ammo. I haven't noticed any issues with other ammo (mostly M-22) that I've fired. I looked at a handful of spent cases and it's pretty clear which ones caused the problem. The cases appear to have split open along the rim, and I suspect that some gas escapes and flows backward along the bolt channel and out at the shooter.
This is the ammo:

Here, you can see the scorch marks on the bolt face near the firing pin. It also looks like some gas gets channelled out of the extractor slot.


If you look closely (hopefully you can see it in the photos) you can see the split in the rim. The two in the front are the suspect ones. The three in the back are fine, and didn't 'vent'.


So, the question remains: is this an ammo problem or is it the gun?
I really like the gun, and I bought the ammo (Canadian Tire, last year) thinking that it was decent stuff.
Any help is appreciated. Thanks!