# Blow back with primer



## justismi28 (Aug 19, 2014)

For those of you that have had blow back issues, how have you handled them? I went out shooting this past weekend, and noticed that I was getting a lot more blow back than I normally get. In fact, most primers were coming out at least half black. 

This hasn't happened before, and I was shooting the same primers I normally do. This was cleaned after my last shooting session a few weeks prior, and all the carbon had been cleaned out. My firing pin bushing gets screwed back into the same position after every cleaning.

The only things I can think of, is the new pack of primers (Winchester W209's) were slightly shorter (a couple thousandths of an inch) than my last packs so my head spacing was off, or my breech plug has been shot out causing the primers to sit that couple thousandths deeper than normal. I wish I had some of my older primers to measure with the calipers against these new ones.

What are your thoughts? Anything I'm not remembering? Suggestions on how to resolve the blowback?

Shooting an Accura V2, Winchester W209 primers, 100gr by volume BH209, Barnes TEZ in different sabots for testing.


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## CPAjeff (Dec 20, 2014)

Total newbie talking here, so I am sure that others with more experience will chime in. I experienced the exact same issue that you are having and mine was fixed simply by switching primers. With the Federal 209A primers, 50-60% of the primers came out black. After switching to CCI 209M primers, all the primers come out clean. I called and talked to Western Powder (makers of BH209) and they said that I could order o-rings that fit down in the primer pocket of the breech plug and that could also fix the problem.

Here is the link to the o-rings;

http://www.mcmaster.com/#catalog/122/3538/=12nzx8r

Product #9262K611


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## DallanC (Jan 13, 2009)

http://www.blackhorn209.com/specs/primers/

PS: On the above MFG link it shows very dirty primers where they had blowback. Isnt the whole point to BH209 to be clean burning? If its so clean burning, how is that poorly fit primer so dirty?

-DallanC


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## justismi28 (Aug 19, 2014)

The blow back is the charge from the primer. It isn't the powder that is blowing back through the flash hole and up the channel. Typically this is caused by a clogged\dirty flash channel or hole that doesn't allow all the primer flame to transfer to the powder. However in this case, I was getting blow back even after drilling the carbon out of the channel and pick cleaning the flash hole. 

One of the reasons I use the W209 primers is they are actually the longest 209 primer available. Typically the W209's measure right about ~.302 while the CCI 209M and Federal 209A are about ~.209.


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## silentstalker (Feb 19, 2008)

I use the W209 and an o ring. Went from partially dirty primer to clean. No blowback.


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## Springville Shooter (Oct 15, 2010)

DallanC said:


> http://www.blackhorn209.com/specs/primers/
> 
> PS: On the above MFG link it shows very dirty primers where they had blowback. Isnt the whole point to BH209 to be clean burning? If its so clean burning, how is that poorly fit primer so dirty?
> 
> -DallanC


I think the claim is clean-er burning. In my experience, BH-209 is about 10 times Cleaner than any other BP substitutes and still about 10 times dirtier than any smokeless powder.------SS


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## sagebrush (Sep 8, 2007)

i highly doubt the primers are longer. i shoot the same accura and have adjusted the head spacing back a couple years ago. its been that long since i have shot it.
is it really necessary to always be moving the head spacing on every cleaning?
are you using the breech plug from cva for BH209? when you are cleaning out the channel on the breech plug are you using a drill bit? if so be careful on twisting it and enlarging the hole prematurely. 
enlarging the hole i believe will cause the blow back.


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