Pitting
- Thread starter passtime
- Start date
Whatever is happening, it's not happening all the time, or with 2000 rounds, the breechface would be a real mess.
Looking at the breechface, I would guess that it's happened less than 20 times over the lifetime of the gun.
I'll bet that if you look at ALL of the empties, you will find a few that stand out.
There will be, but since it's happening just once in awhile, looking at the brass won't provide much information unless you find one of the few empties that caused the problem.
Looking at the breechface, I would guess that it's happened less than 20 times over the lifetime of the gun.
I'll bet that if you look at ALL of the empties, you will find a few that stand out.
I check out my firearms very closely when cleaning. I did a thorough cleaning Wednesday night. That is how I found these pits. I am pretty sure they were not there the last time I cleaned it. The reloads I shoot through this firearm are all the same. I have been using the load data for quite a while. Only thing that varies is brass. I use S&B LPP.
So something changed during your last shooting session.
How many rounds did you shoot your last session?
I feel safe in saying that nothing in the metal of the breechface is spontaneously pushing out bits of metal and leaving pits, which means it's the ammunition.
I would say that during your last shooting session, something like 10-15 rounds leaked gas around the primer. Which means that unless you shot only a very small number of rounds, probably the majority of the rounds you fired were normal.
lee n. field
New member
Any suggestions on what might be causing these pits? The slide is from a Ruger SR45.
Flame cutting, from bad primers, poorly seated primers. I've got that on several guns, replaced a slide on a Glock (on advice of Glock tech support after they looked at it) on that account. I've got a half brick of Tula primers I've set aside, because I'm suspicious those were the source of it.
Forgive my ignorance as I don’t reload, but it really only takes 10-15 rounds to cause this kind of damage?
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My Dad got a bad batch of primers once. Every time a primer pierced, it would cause this type of damage. He knew he had a bad brick but was too cheap to toss them. His primers would fail at random times on random locations of the primer face, not necessarily at the firing pin indent.
I do know from experience that a pierced primer in an AR-15 can burn the tip off of the firing pin. Don't know if a loose primer pocket would create the pin point gas cutting.
Because the pits are mostly spread out, it makes sense that each of the isolated pits was the result of a single incident.
So if you count them up, and assume that the much larger pits could have been the result of two or three incidents that happened to be in more or less the same place, you end up with something between 10 and 15.
It's also possible that one primer could have leaked in multiple places which would mean that it could take even fewer incidents to cause the damage, the assessment above was based on the idea that each of the problem cases only leaked in one small spot.
What I was trying to get at was that looking at only 3 cases from a shooting session that presumably involved a significant number of rounds fired (more than just a few magazines full) won't really provide much information given that the number of faulty rounds was likely quite small--certainly no more than 15, and potentially a lot fewer than that.
lee n. field
New member
Attaching a couple.
I was pretty lax in getting around to cleaning my guns. And, honestly, may not have been as attentive as I should have been, due to known side effects of a med* I had been on for a couple years prior.
Glock looked over the slide, and recommended replacement, which I did.
Springfield looked over the XDS slide, said I could replace. I didn't, haven't had any issues with the gun since.
*The never to be sufficiently abhorred Lupron.
I was pretty lax in getting around to cleaning my guns. And, honestly, may not have been as attentive as I should have been, due to known side effects of a med* I had been on for a couple years prior.
Glock looked over the slide, and recommended replacement, which I did.
Springfield looked over the XDS slide, said I could replace. I didn't, haven't had any issues with the gun since.
*The never to be sufficiently abhorred Lupron.
Attachments
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bedbugbilly
New member
Maybe I am all wet but in your magnified photos, it looks like your firing pin strikes are heavy. Not uniform round like I am used to seeing on my spent primers, Any chance your firing pin is puncturing the primer just enough that you are getting enough blowback through a punched primer to cause gas cutting?
I checked out the suspect batch of one hundred rounds that where last fired through the firearm. I used a magnifying lens to inspect the spent primers and area around them. I also shined a flashlight up into the case mouth to look for pin holes. No pin holes and no real difference in the primers that I posted in the previous post. Then I checked the spent cases I loaded from a one hundred round batch fired before the suspect rounds. In comparison I noticed that the firing pin marks are deeper in the suspect rounds. Also the primers in the suspect rounds themselves were not as deeply seated. Thinking back (a couple of years) the only difference as far as loading between the two batches is that I did not clean the primer pockets. I used to always clean primer pockets on any round I reloaded. That may or may not be the reason for the primers not seating as deep in the suspect rounds? At this point that is the only thing I can come up with. I do believe that gas cutting is what caused the divots. I detected the damage fairly quick but the damage is done. I plan on making up a new batch of loads that will definitely have cleaned primer pockets to see if that alleviates the problem. If I do alleviate the issue what are your thoughts on the amount of damage. Replace the slide or live with it? I lean towards letting it ride for a while. Just an FYI, I asked this same question on THR forum. Please excuse the fact that some of my replies there may mirror the ones here. Thanks to all who have responded so far.