Chinese SKS Shallow/Rough Primer Marks

[Doug S]

After having a pierced primer with a Silver Bear round yesterday, (1 round out of 40 Silver Bear plus another 100 rounds of Wolf without issue) I've been doing a little surfing on the topic of pierced primers. I know from past experience that doing this type of research is a bad idea, because it usually stimulates my paranoid little mind. Well upon looking through primer piercing posts, I noticed something called primer flattening & cratering. I can't remember what the primers look like when fired from my Yugo's (I will take it out soon to compare), but I noticed when looking at a couple of fired rounds that I kept from my Chinese range session today that the primer indents are not very deep. There is no flattening that I can see, but there is possibly a very, almost imperceptible ridge around the outside of the primer dent (Edit: Since I posted this originally, I've found some good pictures of "cratering". My ridge is as I said almost invisible, compared to the pictures I've viewed. I'm still wondering about the shallow indents though). Also a few slight nicks on the primer itself & around the case head possibly from where the round was extracted.

So to summarize, does a very slight ridge, combined with a shallow, rough primer indent sound abnormal pressures or is this fairly typical for the Russian bulk ammo when fired from an SKS? I am just truly a little paranoid, as my rifle has a mismatched bolt, & no serial # on the bolt carrier. Otherwise the rifle functioned great. 140 rounds with not problems at all except the one pierced primer. All fired cases looked normal. In the picture below, the ridge around the indent looks much more pronounced, & the indent looks even a little more shallow, but it gives an okay impression of what the primers look like. Just picture the ridge as barely noticeably, & the indent slightly deeper (if that makes sense).

 

[Tanfj]

Chinese and Yugo SKS rifles use a inertial firing pin,
unlike the Russian ones which have a return spring.

With softer primers I have read of it doing what you describe;
that is why I use hard primered ammo like Wolf.

Wolf ammo is made to full military specs... with hard primers.

Ben Murray of murraysguns.com modifies the firing pin by adding
a return spring... Chinese ones run about $22, Russian/Yugo
runs about $35; although both styles will work in a Yugo.

The website appears to be down at the moment but here is the
address: http://www.murraysguns.com/sksown.htm

 

[JA]

The end of your firing pin looks like this?

\_/

You need to take a file or sandpaper to it and round the sharp edges where the sides meet the flat tip a little. The sharp edge is cutting the primers so rounding it a little will stop the blown primer problem.

 

[Doug S]

Thanks for the info.

 

[Daniel964]

You could also order this.

http://www.murraysguns.com/sksown.htm