Primer blowby - 9 mm handloads

[cmcgehee]

I have wet tumbled with SS pins exclusively using different headstamps with no problems at all. I have also compared depriming prior to tumbling to tumbling before depriming and can tell no difference in the end result. I tumble for approx. 1 1/2 to 2 hours with a little detergent and a squirt of lemonshine. I have never had a problem with primer blow-by.

 

[zaphar]

I remember some people having a similar problem during shortages when using (IIRC) small rifle primers in place of small pistol primers and low pressure loads. Your 5.3gr loads are the starting load according to Hodgdon's online data, and kind of low pressure for 9mm. Do you know if those loads tended to have primer blow-by more than the 5.5gr loads?

Those primers are looking awfully rounded in the picture he posted. My bet would be on using too weak of a loading. CCI SPP have a harder primer cup than FED,REM, and WIN. So take that into consideration and combine it with used brass. The pressure needs to be high enough to expand the primer cup into the pocket or you will have this problem. This is even more apparent when using SRP in place of SPP.

 

[Stefano189]

cmcgehee: I'm glad to see there are other reloaders using the SS pins to clean their brass. I follow almost the same process you do with a Lortone tumbler equipped with two 3 lb capacity containers. I find it does a very good job. Thanks for your input and experiences. I have reloaded 150 cases twice now using 3 different manufacturers and thus far I've seen no indication of primer blow-by but it's probably too early to see the problem.

zaphar:Thank you for your comments. I was not aware of the hardness of CCI SPPs. The current load I'm using is 5.8 gr of Alliant Power Pistol with a 115 gr Montana Gold JHP, COL 1.090. This is a load from the Hornady manual modified to account for the longer (~0.015") Montana Gold bullet. Being relatively new to reloading I wouldn't use SRPs as substitutes for SPPs.

 

[Stefano189]

Primer blowby - 9 mm handloads - update

I have reloaded 150 cases three times now using 3 different manufacturers (Blazer, Fiocchi and Magtech) and thus far I've seen no indication of primer blow-by. I've also purchased a Primer Pocket Go-No Go tool.

 

[Dudedog]

Glad to here there are no issues with the newer brass.
Sure sounds like the other brass was just worn out.

 

[Stefano189]

Dudedog: Just finished the fourth reload sequence and there is no indication of problems with blowby. I'm in the process of reloading the fifth set and will let the folks know what the results are. I suspect that there are a few reloads remaining with this brass but I will let the results inform. Since there is usually no one at the range when I'm there I'm able to collect every piece of brass that I fire. I'm also comparing the stainless steel pin cleaning method with a dry method (tumbler with barley) to determine if the cleaning method is a factor. Personally I don't think it has an effect judging from other responses.

 

[Stefano189]

I have just completed firing the sixth round of reloads (150 rounds; Blazer brass, Fiocchi brass, Magtech brass) with no sign of primer blowby. The 7th round of reloads is in process. Will continue to provide results as they become available. Nothing in the process has changed. Cleaning brass with stainless pins (Magtech and Fiocchi) and barley (Blazer). Loads are the same - Power Pistol, 5.8 grains, COL 1.09", 115 gr Montana Gold JHP bullet.

 

[Stefano189]

Primer blowby - 9 mm handloads - update

Recap....

Three boxes of factory cartridges (Blazer, Magtech, Fiocchi – 150 total) were fired and then reloaded 9 times with no indication of primer blow-by or leakage. However, while there was no primer leakage, incipient case fatigue was observed on all Magtech and Fiocchi cases as shown in the accompanying photos. The ridge seen in the photos is barely discernible when running a fingernail across it and only appears over one half of the case (approximately), at the half where the extractor engages the case. There was no indication of case fatigue in any of the Blazer cases.

The Magtech and Fiocchi cases will be scrapped and recycled but I will continue to reload the Blazer cases until such time as an anomaly appears. Two case cleaning methods were used, stainless steel pins (Magtech and Fiocchi cases) and barley grain (Blazer). There was absolutely no visible difference with regard to primer pocket condition between the two methods over the number of reloads.

With regard to the primer leakage condition discussed in this thread and after some reflection on the problem I believe the leakage may have been related to the primers given that this is the only common element other than the cleaning method which has been shown above not to be an issue.

I believe I had indicated previously that CCI 500 SPPs were used exclusively but I recall that I also had one box (1000) of Remington 1-1/2 SPPs and possibly some of those primers may have been slightly undersized. Unfortunately I cannot reconcile the start of the primer leakage with the use of the Remington primers. For the 9 reloads mentioned above, totaling 1350 rounds, only CCI 500 SPPs were used.

For some reason the website would not allow the photos to be uploaded. I will do so when the issue is resolved.

 

[243winxb]

CCI sp and spm primers, at times, run on the larger side. Thanks for the update.

 

[Stefano189]

Photos previously alluded to in my last message are now posted. Please comment as appropriate.

 

[Stefano189]

Primer blowby - 9 mm handloads - update

After 10 reloads of 50 Blazer cases there was no indication of primer blow-by or primer leakage. However, after decapping, resizing and cleaning (wet tumbling) and examination of the cases, one was found to be split but just short of the mouth of the case. I will reload the remaining 49 cases and report any additional anomalies.

 

[243winxb]

The ridge seen in the photos is barely discernible when running a fingernail across it and only appears over one half of the case (approximately), at the half where the extractor engages the case.

I dont like how this looks. Hot load may take many firings to make the brass unusable. But sometmes as little as 3 firing will do it.

 

[vaalpens]

I'm not questioning your conclusion that you are seeing "incipient case fatigue", but it just seems you have a high percentage based on your numbers.

I have seen something similar a while ago on some of my 357sig brass, but I know it was due to some case bulging and then the re-sizing die actually creating the little ridge. I resolved it by debulging any range brass first before doing any re-sizing. I also use a little bit of lube before re-sizing and haven't seen the same issue again.

I'm not saying what you see and what I have seen are the same thing, but I am still learning and would like to be able to identify these types of failures.

This is a picture showing the ridge that was formed on my 357sig brass.