Need help with diagnosis - 357 Blowback
- Thread starter Muffin Man
- Start date
Yendor357
Member
I have another theory.
This is based on what I experienced recently.
Far and away, I shoot my reloads, but recently, I chronoed some factory 158 Winchester 357 in my new production 4 inch Python. Although less severe, I experienced something similar to Muffin’s. I remember thinking “this doesn’t happen when I shoot my reloads”. And I shoot some pretty warm reloads occasionally. But I seldom shoot factory ammo, so I didn’t think much of it.
Here’s my theory:
The brass particles you’re getting blasted with were already in the case when the manufacturer charged the cases with powder.
The brass particles are likely the residue of the final trimming process, or from possibly from punching the primer hole. But I’m betting from final trimming. So when the ammo is fired, the brass particles become projectiles, as well. Some are small enough to pass through the b/c gap.
If you could carefully pull several of your factory loads apart and were able to carefully examine the contents of the case, you could verify or disprove my theory. But to do so would require lab quality conditions.
If you had a 357 rifle, and who doesn’t have at least a couple?, you could staple up several sheets of white typing paper on new, thick cardboard. Fire a shot from maybe 5 feet. Then examine the powder burn.
My guess is as worthless as everyone else’s. But I’ll bet there is nothing wrong with your revolver. You just have ammo containing brass contaminated propellant.
This is based on what I experienced recently.
Far and away, I shoot my reloads, but recently, I chronoed some factory 158 Winchester 357 in my new production 4 inch Python. Although less severe, I experienced something similar to Muffin’s. I remember thinking “this doesn’t happen when I shoot my reloads”. And I shoot some pretty warm reloads occasionally. But I seldom shoot factory ammo, so I didn’t think much of it.
Here’s my theory:
The brass particles you’re getting blasted with were already in the case when the manufacturer charged the cases with powder.
The brass particles are likely the residue of the final trimming process, or from possibly from punching the primer hole. But I’m betting from final trimming. So when the ammo is fired, the brass particles become projectiles, as well. Some are small enough to pass through the b/c gap.
If you could carefully pull several of your factory loads apart and were able to carefully examine the contents of the case, you could verify or disprove my theory. But to do so would require lab quality conditions.
If you had a 357 rifle, and who doesn’t have at least a couple?, you could staple up several sheets of white typing paper on new, thick cardboard. Fire a shot from maybe 5 feet. Then examine the powder burn.
My guess is as worthless as everyone else’s. But I’ll bet there is nothing wrong with your revolver. You just have ammo containing brass contaminated propellant.
First thing I would do is have a competent gunsmith re-cut the forcing cone. Then try it.
BoulderTroll
Member
- Joined
- Mar 20, 2010
- Messages
- 287
- Reaction score
- 433
That's the first thing you would do?? Two different, NEW revolvers are having the exact same problem, while shooting the same (arguably poor quality) ammo, and the first thing you'd recommend he do is take both of them to a non-factory gunsmith to have them worked on? Help me out with this thought process. You wouldn't try different ammo? You wouldn't send one or both new revolvers back to S&W? What you're saying is like someone going to the doctor and telling him, "I've got a headache", and the doctor immediately replies, "OK, the first thing we'll do is surgery to remove any possible tumors."
Yendor357
Member
Right on Troll!
I’ll pile on….
His guns are spitting BRASS. Not lead. Not copper. From where does brass come? Of what is the cartridge case made?
Duh…..
I’ll pile on….
His guns are spitting BRASS. Not lead. Not copper. From where does brass come? Of what is the cartridge case made?
Duh…..
OP
Muffin Man
Member
- Joined
- Jan 25, 2025
- Messages
- 20
- Reaction score
- 20
Thanks everyone. I just got back from the range and I got peppered in the face again. The gun was thoroughly cleaned before shooting. Also, after shooting the first 6 rounds the cylinder wouldn’t close. I called S&W, and they asked me to send it back and also had me give them some info regarding my injury.
I’ve had so many issues with the last three new S&W revolvers. I’m done with them for now; maybe forever. Two times they bent my rear sights before sending my repaired revolvers back to me. It took them two repairs (8 weeks each) to properly put on my front sight on a 629 PC, which came loose. Another revolver’s front sight came loose as well from the first 50 rounds. They fixed it, but sent it back with a severely bent rear sight. Now, I had this (carry comp 19) sent in for repair because it was giving me light primer strikes, and now I’m dealing with this blowback and cylinder not closing issue.
I’ve had so many issues with the last three new S&W revolvers. I’m done with them for now; maybe forever. Two times they bent my rear sights before sending my repaired revolvers back to me. It took them two repairs (8 weeks each) to properly put on my front sight on a 629 PC, which came loose. Another revolver’s front sight came loose as well from the first 50 rounds. They fixed it, but sent it back with a severely bent rear sight. Now, I had this (carry comp 19) sent in for repair because it was giving me light primer strikes, and now I’m dealing with this blowback and cylinder not closing issue.
-BTM-
Member
I believe OP Described the debris as gunpowder or dark brass.
gwpercle
Member
Try different ammo before you do anythimg ...
my gut feeling is the problem is in the Ammo's Maker's powder choice , unburned particles, getting blown back ... happens with some slow burning magnum powders .
Gary
my gut feeling is the problem is in the Ammo's Maker's powder choice , unburned particles, getting blown back ... happens with some slow burning magnum powders .
Gary
BoulderTroll
Member
- Joined
- Mar 20, 2010
- Messages
- 287
- Reaction score
- 433
And just to confirm, since you didn't mention it specifically; you used a different brand of ammo this time? Also, you said, "the gun", but earlier you told us both revolvers were having the same issue. Are you returning both?
I had a SAA revolver that hated Sellier and Bellot ammo. It shot everything else perfectly, and would hang up, jam, and spit with Sellier and Bellot, which is normally pretty decent quality. As a former armorer, all I can say is that ammo is the number one cause of firearm issues, and operator error is number two. Everything else is WAY down the line. My thought process is that until a "problem gun" is shot using high quality ammo, and a different shooter, the gun is the least likely factor in the equation.
Last edited:
Yendor357
Member
Oh, dark brass. So much different from the light brass we used to use. That completely changes everything.
What next?
I still like my old Smiths. Always will. These new ones aren’t the same.
What next?
I still like my old Smiths. Always will. These new ones aren’t the same.
Since these are new S&W revolvers, I think you are wise to send them back to S&W. It is sad, but S&W's quality control department currently seems to be the buyer of their products.
