Let's Talk Primers

[LostInJersey]

So for a while, when I was reloading .223 for my Ruger American Ranch, I just figured I'd start with some CCI 400s. When I starting reloading 6.5 Creedmoor, I continued to use the CCI 400s. I also bought some Winchester small rifle primers for variety as I know a friend who likes them.

Using standard primers seems to be in the minority for benchrest shooters, especially at the higher skill levels. I know some people say to use magnum primers instead. CCI has their benchrest primers which are supposed to be their highest quality. How much does this really make a difference between standard vs. magnum vs. benchrest? Honestly, I don't see much if any unburnt powder so I feel like magnums won't do much more.

What are your experiences switching between primer types?

Edit to add second question: Is there a different primer I should be looking at?

 

[rweaver00geo]

different primers have an effect on velocity, the SD/ES number and accuracy. what powder are you using in your 223 load? Do you have a chrono? CCI400 is fine thats what I started with then I switched to a Rem7 1/2 only so my bolt gun and AR could share the same primer. The 6.5 may benefit from a hotter primer but im guessing on that.

 

[Steel head]

#400’s are fine as long as you not pushing the limits with pressure.
An excellent primer.
If your getting spicy #450 will take the heat as they’re pretty durable.

I don’t even use magnum primers in my magnum.

I use lots of regular CCI primers.
#450 for AR’s and #200 for my 260 and 7 saum.

I recently switched to FGMM large rifle because I got a really decent deal on them.
Loads didn’t change one bit but I did have one of my best days shooting my 7 saum last week with the new primer

 

[lightman]

I've always favored CCI primers. Over the years I have just had fewer issues with them. Although primer issues of any kind are scarce, CCI just seems to fit everything better. I started using Federal Match primers in my match ammo, mostly because............. Truthfully, I can't see much difference between either Federal Match primers or CCI match primers compared to standard primers.

 

[spife7980]

I don’t even use magnum primers in my magnum.

I use lots of regular CCI primers.
#450 for AR’s and #200 for my 260 and 7 saum.

450 is a magnum primer

I used to use the 400 in my 223 but like I was always told “eventually you’ll start popping them”... and I did. I use the 450s now and have much less cratering and zero holes blasted through my primer.

 

[Steel head]

450 is a magnum primer

I used to use the 400 in my 223 but like I was always told “eventually you’ll start popping them”... and I did. I use the 450s now and have much less cratering and zero holes blasted through my primer.

I know,,,,,,,,it’s a commonly used primer in hot 223’s in AR and bolt guns and recommended as far as I’m concerned.

I was using regular as in not bench rest or white box variations

 

[LostInJersey]

different primers have an effect on velocity, the SD/ES number and accuracy. what powder are you using in your 223 load? Do you have a chrono? CCI400 is fine thats what I started with then I switched to a Rem7 1/2 only so my bolt gun and AR could share the same primer. The 6.5 may benefit from a hotter primer but im guessing on that.

The powder I use depends on what ammo I'm loading. 52gr and 55gr I've been using H335. With the 69gr, I've found H4895 was giving be the best/most consistent velocities. 77gr I was using H4895 also but now that I have multiple pounds of Varget, that's what I plan on using.

6.5 Creedmoor I've been using 40.3gr of H4350 (142gr SMK). I'm not shooting too far so I don't need the extra velocity. Haven't chrono'ed it yet, but it's right around a node and is stupid accurate.

I do have a chrono but I was shooting indoors all winter and all the ranges closed down during the pandemic. I need to join an outdoor range so I can use my chrono more.

 

[rweaver00geo]

If you havent had any primer issues using the cci400 in the 6.5 creed than I wouldnt change. If and when you chrono the load if your not happy with the numbers then I would consider changing. For you H335 load, since its a spherical powder it may favor a magnum primer and that might show up over a chrono but if it accurate I would stick with the 400's. Experimentation with primers is always fun, rewarding and can be frustrating . you never gonna know whats going to happen.