.223 with CCI standard, magnum primers

[DownhillFromHere]

I recently started handloading .223 Remington. Question below.

Long story short, I bought a few thousand of each:

• CCI 450 magnum small rifle primers - intended for SRP 6.5CM brass and .223 with ball powders
• CCI 400 standard small rifle primers - intended for .223, especially plinking loads with 55gr bulk bullets.

Again, shortening the story, I have found that loads which shoot fine in my Tikka T3X Varmint bolt gun (decent accuracy, no excess pressure signs, acceptable ES/SD) with CCI 450s show excessive primer flattening with CCI 400s with the exact same powder load. Different powders (IMR-4895, H335, CFE223), different bullets (55gr FMJBT, 77gr SMK), all loads worked up from Hornady data. Brass is once-fired new (not remanufactured) brass from Defender Ammunition, a veteran-owned&operated business I like to support.

I understand that the standard primer has a thinner cup than the magnum, which explains the difference in pressure tolerance (velocities are maybe 10-20fps higher with the magnums - no surprise).

So, my question is simple: Am I correct in thinking that the badly flattened standard primers are a harmless byproduct of the thin cup, or are there potentially harmful effects of which I'm not aware? I have not had any pierced primers, and cratering is minimal to nonexistent with the 400s. Pierced primer would be an instant show stopper.

Here's an example: 55gr FMJBT, 25.0 grains H335, once-fired Defender brass. Top two are CCI 450, bottom three are CCI 400.

 

[LawnMM]

Just buy 450s, what's the savings of a 400 over a 450? 4 cents?

 

[spife7980]

They are currently a harmless byproduct but like anything, if they stretch too thin they could fail. With all the variables Im not sure anyone could tell you how close you are to that point.

This is why you should be paying attention to all the pressure signs and not just the primer appearance.

 

[DownhillFromHere]

Just buy 450s, what's the savings of a 400 over a 450? 4 cents?

I will from now on. I now understand, from reading and experience, that the 400s aren't optimal - especially for use in an AR. When I started, I saw no sense in spending more than I needed to. But now I have four thousand of them; they're gonna get used for something. Live and learn.

They are currently a harmless byproduct but like anything, if they stretch too thin they could fail. With all the variables Im not sure anyone could tell you how close you are to that point.

This is why you should be paying attention to all the pressure signs and not just the primer appearance.

Right. The .223 is a "trainer;" I don't expect to be competing with it. So now that I'm getting a minimal idea of load behavior with different component combinations, I'll use the 400s for very mild loads. I read somewhere here on SH that CCI 400 SRPs are effectively the same as CCI magnum small pistol primers, so I may use some of them for pistol loads, just to use them up.

 

[LawnMM]

My point is, don't risk it, if they don't work find another use for them.

Sell them to some fudd at the range and use the cash to buy more 450s.

 

[spife7980]

They aren’t ideal for the high pressure but I still shoot 400s in my 223s almost exclusively. I leave the 450s to the dasher.

I’ve found I start to get heavy bolt lift about the same time I get the 400s flattening too much. Pushing them with a 450 would only allow me to push them further toward over pressure.

 

[DownhillFromHere]

They aren’t ideal for the high pressure but I still shoot 400s in my 223s almost exclusively. I leave the 450s to the dasher.

I’ve found I start to get heavy bolt lift about the same time I get the 400s flattening too much. Pushing them with a 450 would only allow me to push them further toward over pressure.

Which powder(s) are you using now? I've searched threads here and can go back and find your posts - I've seen them....

I ended up with a couple of pounds of IMR4895 and H335 first because I couldn't find anybody with Varget or 8208 in stock when I made a big order (brass, bullets, primers, powder). I was disappointed with velocities I was getting with those so I paid big bucks at my LGS for a pound of CFE223. I don't care about loading max-pressure/max-velocity loads, really. Still in that learning stage, where it's especially easy to chase velocity.

Thanks for the feedback.

 

[spife7980]

I use 8208xbr and varget with it mostly leaning 8208. Basically 23.5-23.8 of 8208 with any 50-80 grain bullet will be golden I’m finding.

Figures right, what I would suggest is what you don’t have lol

 

[antithesis]

Are you certain that 400's have a different cup thickness than 450's? I have heard that for years, as I did that 41's were thicker than 450's. I asked CCI directly about the 41 vs. 450. They said they are exactly the same primer only the 41's have a different angle in the anvil to reduce slam fires.

I wish I would have asked about the 400 v 450, not that I still could not, but I ran across an article by Allan Jones (worked at CCI) where he says the difference (post 1989) between a standard an magnum CCI primer was the magnum had a more aggressive mix. He did not mention anything about the cup.

 

[spife7980]

It’s a bit old but it seems to have held up to scrutiny this far

 

[KTAK]

If you are going to use Magnum primers you want to download the powder.... Flattened primers are not a harmless byproduct. In my rifles, everytime I have flattened primers there has been a difference in recoil, I can feel the gun getting "hammered". Most of my 308 loads are reduced almost 2 grains when I use Magnum primers.... and I use a lot of them. And remember if your load data doesn't include Magnum primers you are coloring outside the lines.....