CCI 550?

[Soupcan]

Beginning reloaded here (at a terrible time to be a beginner). I’m trying to secure materials to load 6.5 creedmoor and 6br. I have some CCI 550 primers and am curious if anyone has any practical experience using these primers in place of small rifle primers. I’ve read that they are identical to CCI 400 and I have also read they are not. If anyone has direct experience and could weigh in on their use (positive or negative) for either 6br or 6.5 creedmoor, it would be appreciated. Thank you!

 

[918v]

You could if you don’t make a stupid load. What powder/bullet/proximity to the lands?

 

[Soupcan]

H4350 with 147 eldm for the 6.5.
Norma 203b and something in the 105 range for the 6br

 

[Bigfatcock]

The cup should be hard enough for the pressure. Doubt you’ll have any issues.

I went the opposite route a decade ago and started using SRP for pistol as well so I only have to stock one primer. The only issue is cup hardness for pistols with light hammer falls.

To answer your question, you should be fine. Watch for abnormal primer flow from the first few shots, and if all is good then carry on.

 

[918v]

The problem with what you read on the internet is that it might be true at the time it was posted, but specifications change. 550 cups might have been as thick as 400 back in the day but what about today?

A friend of mine runs 39.5grs of H4350 with the 147’s. It’s a moderate load. You might be able to get away with it. Just watch out for pierced primers.

 

[TxWelder35]

I’d try it on a not high pressure round. Some Google fu says they are the same

 

[FLIGHT762]

According to a very good thread / article on primers on the SKS boards:https://www.sksboards.com/smf/index.php?topic=56422.0
The #550 has the same cup thickness as the #400.

A footnote from the article:

This article was posted in 2009 and updated in 2013.

 

[Bigfatcock]

A simple inside micrometer will tell the tale. Even a good set of calipers will get you good enough.

 

[Soupcan]

A simple inside micrometer will tell the tale. Even a good set of calipers will get you good enough.

Good point. I’ll measure one and see what I get.

 

[Soupcan]

According to a very good thread / article on primers on the SKS boards:https://www.sksboards.com/smf/index.php?topic=56422.0
The #550 has the same cup thickness as the #400.

A footnote from the article:
View attachment 7574774

This article was posted in 2009 and updated in 2013.

I read through that article as well. I’ve also seen some conflicting information. Appreciate it!