It is not easy to admit this especially to myself but in the hopes of helping someone else I am going to. I use a Lee Classic Turret Press for my handgun cartridge loading. For those who may not know it the Classic Turret Press uses two sizes of Primer Arms for seating pistol primers. Small size for small pistol primers and large for large pistol primers. Simply put after loading a batch of .357 mag loads and before loading the suspect 45 auto loads. I did not replace the small pistol primer arm with the large pistol primer arm needed for my 45 auto brass. Maybe I burned a few too many brain cells in the Seventies. Anyway I believe the problem is solved. Thanks again for the help. It pointed me in the right direction.
Pitting
- Thread starter passtime
- Start date
The reason it does not look like gas cutting to me is primer leakage gas cutting will be around the firing pin hole,where the gas is jetting past the primer.
Those "pits" are located out near the rim diameter.
I cannot see any gas getting to that location still carrying the heat and pressure to cut.
I don't think its gas cutting.I don't think its about the primer.
The rims of those cases look torn up. The beat up rims are at the right diameter to match the dents in the breech face.
You get to be the one to play detective.I don't have the gun to look at.
I suppose a bit of contamination could have embedded in the brass.
But there is something else. Solids are not compressible. I spent a career building and running plastic injection molds.These were mostly developmental molds. The steel was "pre-hard". It was roughly a 4140 alloy,semi-hard,but machinable with high speed.
The parting line ,where the mold halves separated,would start out surface ground flat.Pristine! Beautiful!!
But if flakes came off the sub gate break,or of wet material caused nozzle drool,or if for any other reason bits of nylon or Delrin or Lexan or any other plastic remained on the plates when the mold press clamped up,
That plastic would be pressed into the steel and it would displace the steel.
The plastic is mallable,but its not compressable.
If the mold was made poorly,and ran dirty, some parting lines literally looked like they had been worked over with a hammer.
That beat up brass may be impressing into the steel. The high spots focus all the force on a very small area.
There is something else that could aggravate the situation.I know nothing about how Ruger makes those slides.I doubt they are machined of bar stock.
Ruger has been an innovator of production methods. No one is better at investment casting.
IMO.its possible that slide or breech face is a powdered metal.sintered part.
Pressed and baked like a cookie.I'm not saying it is,but modern manfacturing methods are a fact.
Looking at your breech,zoomed up,those are dents,not gas cuts,IMO
Those "pits" are located out near the rim diameter.
I cannot see any gas getting to that location still carrying the heat and pressure to cut.
I don't think its gas cutting.I don't think its about the primer.
The rims of those cases look torn up. The beat up rims are at the right diameter to match the dents in the breech face.
You get to be the one to play detective.I don't have the gun to look at.
I suppose a bit of contamination could have embedded in the brass.
But there is something else. Solids are not compressible. I spent a career building and running plastic injection molds.These were mostly developmental molds. The steel was "pre-hard". It was roughly a 4140 alloy,semi-hard,but machinable with high speed.
The parting line ,where the mold halves separated,would start out surface ground flat.Pristine! Beautiful!!
But if flakes came off the sub gate break,or of wet material caused nozzle drool,or if for any other reason bits of nylon or Delrin or Lexan or any other plastic remained on the plates when the mold press clamped up,
That plastic would be pressed into the steel and it would displace the steel.
The plastic is mallable,but its not compressable.
If the mold was made poorly,and ran dirty, some parting lines literally looked like they had been worked over with a hammer.
That beat up brass may be impressing into the steel. The high spots focus all the force on a very small area.
There is something else that could aggravate the situation.I know nothing about how Ruger makes those slides.I doubt they are machined of bar stock.
Ruger has been an innovator of production methods. No one is better at investment casting.
IMO.its possible that slide or breech face is a powdered metal.sintered part.
Pressed and baked like a cookie.I'm not saying it is,but modern manfacturing methods are a fact.
Looking at your breech,zoomed up,those are dents,not gas cuts,IMO
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To see where the rim of the case would be, look at the extractor in the picture. The rim will fit UNDER the edge of the extractor. If the rims were where the pits are showing up, the extractor could never reach them and the gun would malfunction.
You can also see the polish mark on the extractor where the case rims have rubbed against it. Well outside the ring of pits.
The pitting is much closer to the firing pin hole than the rim of the cartridges. The pitting is right where the edges of the primer pocket would be.
There's no way that the rims are denting the breechface and leaving those marks. For one thing, brass is not hard enough to dent steel. For another, if they were somehow hard enough to dent steel, they wouldn't be making little pits, they would be making rim-shaped dents. And finally, the dents would be where the edge of the rims hit against the breechface, not where the edge of the primer pockets are.
The gas isn't leaking out of pierced primers, but around the edges of a primer, probably due to loose primer pockets or something similar.
Given your reference to the extractor,I looked at it again.
OK. I can see my sense of scale was off. You have convinced me. I got it wrong!!
It happens.
With the pitting at primerpocket diameter, I agree with gas cutting/leaking around the primer.
To the recycle bin with the rest!!
OK. I can see my sense of scale was off. You have convinced me. I got it wrong!!
It happens.
With the pitting at primerpocket diameter, I agree with gas cutting/leaking around the primer.
To the recycle bin with the rest!!