I recently made the switch from 6.5 creed to a 25x47. I had a small stash of CCI400’s I planned to use during the primer shortage since I switched to Lapua small primer brass. Loaded up a 2 rounds per charge weight from 39.6 to 41 gr H4350 and pierced a primer at 41 gr. Backed off to 39.8 and loaded 43 rounds for a small match last weekend and saw quite a bit of cratering and 1 very close to piercing. Do I just need to back down even more or am I going to struggle with pierced primers no matter what until I can find some 450’s or BR4’s? I’ve also seen where the 400’s are not recommended for use in AR’s so what are they good for?
- Thread starter PWOCengineer70
- Start date
Good for most anything. You may have to tweak your powder charge a bit, but that's all. The 400s have a bit softer cup than the 450s and BRs, but you can get them to work. Also, if you are using a Rem700 that has not had the firing pin bushed, cratering primers is common.
You're missing a few things. What is your bullet weight, do you have velocity readings, how far you you off the lands?
It is possible to use the 400 primers in the 6.5 Creedmoor but you at minimum should have a small diameter firing pin with a close fit in the bolt face.
Due to them having a thinner cup there is still a risk of piercing them.
Due to them having a thinner cup there is still a risk of piercing them.
CCI #400 really have no place except moderate 223 loads or lower pressure loads like 22 hornet.
I agree with you on that one but many use them for the mid sized rounds.
I personally don't want to risk torching the face of any of my bolts and years ago standardized on the 450's but still have a couple 1000 cci400 primers that may end up getting used for small pistol loads.
I have a nice load worked up in cci400's, started piercing. I switched it to br4, supposedly it has the same heat with a thicker cup.
Thanks for all the reply’s so far. I’m using the blackjack ACE 131 gr bullet .030 off the lands, impact action, 26” Bartlein barrel in 25x47.
39.6: 2812, 2829
39.8: 2853, 2849
40.0: 2886
40.2 no reading
40.4 no reading
40.5: 2911
40.6: 2927, 2922
40.8: 2923, 2927
41.0: 2949, 2952 blown primer
I’ll probably test 39-39.5 next and start looking for new primers.
39.6: 2812, 2829
39.8: 2853, 2849
40.0: 2886
40.2 no reading
40.4 no reading
40.5: 2911
40.6: 2927, 2922
40.8: 2923, 2927
41.0: 2949, 2952 blown primer
I’ll probably test 39-39.5 next and start looking for new primers.
Yeah, I was hopeful I could get the 400’s to work for now. Finding a unicorn may be easier than finding 450’s.
It looks like you had a nice flat spot in your ladder between 40.6 and 40.8.
The real question is will the primer cups hold on at that speed and pressure.
The real question is will the primer cups hold on at that speed and pressure.
The 40.7 gr area would be interesting to explore for sure. Have you looked for any issues with your bolt and firing pin. Making sure that your firing pin is not extending too far and making sure that it fits you bolt face properly by bushing the firing pin might solve your issue.
He allready stated he was using an Impact action so sloppy fit wouldn't be an issue, the real issue is using a primer that is rated for moderate pressure rounds and the 25x47 certainly doesn't fit that criteria.
Has anyone had to bush an impact bolt? I did a search and couldn’t find anything. I do really like the 40.6-40.8 range and it’s tempting to try again but I’m pretty sure the primers wouldn’t hold up. I don’t want to risk messing up my new action for a little velocity gain. Even at 2800 my dope is 1 mil less than my 6.5 CM was at 1000
You're right I missed the impact action that should mostly rule out issues in that area.
I snagged a thousand of them at a LGS and have been using them on a Rem 700 223 without issue.
Would not be my first choice, I recall hearing somewhere that the CCI 400 and CCI 550 pistol primer is the same primer.
I always wondered about the primer dimensions on that chart so I measured a CCI 400 and a CCI 450.
Would not be my first choice, I recall hearing somewhere that the CCI 400 and CCI 550 pistol primer is the same primer.
I always wondered about the primer dimensions on that chart so I measured a CCI 400 and a CCI 450.
| Cup Thickness | Cup Diameter | Cup Height No Anvil | |
| CCI 400 | .0195 | .1754 | .1102 |
| CCI 450 | .0259 | .1755 | .1131 |
I’m running 400’s with Peterson dasher brass in a lone peak Fuzion. No problems.
I’m running BR speeds though. 2790 with 30.0 varget.
I’m running BR speeds though. 2790 with 30.0 varget.
I do have some Varget I could try instead of 4350 if that might make a difference. I would like to try to find a node around 2800
Small pistol primers are not the same a small rifle primers. They have a cup thickness of .017".
A pretty good primer description here rather than the same old primer charts that get re-circulated
Primer Info & Chart + Milspec Primers for Semi-Autos & Other Primer Applications
Primer Info & Chart + Milspec Primers for Semi-Autos & Other Primer Applications
www.sksboards.com
^^^ The link works^^^ don't know why it says there'a an error.
My all around small rifle primer is the Remington 7 1/2. I don't buy the CCI 400's. I would use them if that's the only primer that is available.
Did you specifically find the spec for small pistol MAGNUM vs the 400s?
Edit-
Looks like .017 vs .020.
If loads were worked up, I wouldn't sweat 400s for pistol in a pinch.
I still use them happily for my pew pew 223loads with cheap 55’s and a moderate load of W748.
If you don’t push them they work very well and I’ve never had any issues shooting thousands of them once I learned their limitations.
I DEFINITELY don’t use them for my hot 77smk loads.
I do know someone who uses the #400 for hot 38 super loads.
Understood, pretty much all I have ever used them for is relatively mild though not sedate 223 ammo in AR platform.
I had what I thought was a slam fire about 10 years ago though it could have been a double tap on a light 1lb Jard trigger in a varmint weight AR and have used cci450 every since..
