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+--- Thread: CCI 400 limits (/showthread.php?tid=266)
CCI 400 limits - Lemonaid - 03-28-2021
My first hand loads were Hornady 6.5 Grendle brass sized to 6 arc, CCI 400 primer, Nosler 105 RDF, and Lever started at 27.5 grains seated to 2.280.
The 27.5 load worked o.k. but primer cratering occurred.
at 27.8 accuracy was good (.610 for three shots) but the third shot popped a primer.
I have a good supply of CCI 400's, but only a few of other makers as the reason I started with them.
I would like to hear from others that have used the CCI 400's in the 6 ARC, perhaps with more success with lighter bullets or other powders.
RE: CCI 400 limits - StoneHendge - 03-28-2021
Did you check your seating depth to lands? My Hornady comparator told me ~2.275" to the lands in my 16" Lilja for 105 RDFs and a dummy round confirmed it. I've got my 1st set loaded up for testing at 2.25" since I had success with both .308 175 and 6.5mm 140 RDFs 0.03" off the lands. If your jamming into the lands at 2.28", that could be contributing to pressure on a primer.
I would have shot them Thursday but the wind was too Gusty to make load development worthwhile.
RE: CCI 400 limits - CZ527 Guy - 03-29-2021
The discussion in the linked thread may go a long ways towards answering your questions.
https://www.ar15.com/forums/armory/CCI_400_vs_CCI_450/42-417059/
RE: CCI 400 limits - Old Bob - 03-29-2021
AR or Bolt gun? 27.5/27.8grs of Lever is still below max for AR pressures using 105gr bullets but what about your OAL? How far off the lands is your 2.280" load? Being too close or actually touching the lands is the only thing I can think of which might cause higher pressures & flattened or pierced primers. Most data I've seen has the OAL at 2.26" or less so they'll fit in AR magazines.
Repeating what's been previously said about CCI primers... CCI 400 primers are standard small rifle primers. CCI 450 are small rifle magnum & CCI #41 are Military grade. Both of these have thicker or harder primer cups than the standard primer. Except for the extreme high pressures, piercing shouldn't happen but you'd still see flattening. Use 400s for bolt guns & 450s & #41s for ARs.
The two previous posts were made while I was writing mine. Sorry for some redundancy...
RE: CCI 400 limits - Lemonaid - 03-29-2021
This is in a gas gun, Monster 20" bbl. Jam for Nosler 105 rdf for this barrel is at 2.340"
The primers didn't flatten a whole lot, but did crater a medium amount.
I've had primer piercing in my bolt 6ppc 1-7 twist rap with RL15 and CCI 400's at modest load levels with the 105 class projectiles.
I would much prefer to use a stouter primer, but only have a hundred or so of CCI 450's right now.
My suspicion is that the 400's will only hold up to medium pressure loads in the 6 ARC or similar cartridges although they work pretty good in .223.
I'll check out the link CZ guy posted and see what insights can be found.
RE: CCI 400 limits - CZ527 Guy - 03-29-2021
James Calhoon did as good of an explanation on primers as I have seen published yet. The following link is his published data you will see the CCI 400 cup is thinner (by a little more than 11%) than the federal 205 primer most commonly recommended by Hodgdon & Hornady Load data. In any times the following data can be useful & especially in times of shortages.
Measuring cup thickness is relatively easy to accomplish. Cup hardness may require instruments fewer of us have at our disposal.
http://www.jamescalhoon.com/primers_and_pressure.php
RE: CCI 400 limits - Lemonaid - 04-11-2021
I'm not sure if this is the best place to post this but here goes.
Great day at the range, I am liking initial results with the Monster 20 ARC. The fast twist 6PPC found a nice load as well. These were all with CCI 400's despite what I wrote by habit on the target.
Best load so far with the ARC is Nosler 105 RDF, Lever at 27.3, 2.250" oal and Hornady converted 6.5 brass, CCI 400 = 1.300" for 9 rounds
Best load so far the the 6PPC RAP is Barnes 105 Match Burner, 27.8 of Lever, CCI 400, 2.270", Hornady converted 6.5 brass 9=.650, last round nose dived and messed up the bullet a bit.
I traded some CCI 200 for some Remington 7 1/2 primers so I can up the powder some. I might not change the 6PPC load[attachment=222]