primer differences

[captn-tin]

Recently ran out of CCI41 primers that I had been using for my 5.56 reloading using 25gr of h335 und a 55gr fmj bullet. Would I see much difference using CCI 400 srp or Fed 205m match srp. I know I'll have to load up a few and check em out, but thought maybe one of you guys out there might have tried em. Thanks in advance.

[sghart]

You won't see a noticeable difference.

[divingin]

Cup thickness is, AFIFK, the primary difference between 41's and 400's. 41's have a thicker (and possibly harder) cup to minimize slamfires.

Fed's are known for soft cups. Federal does sell an AR Match primer; I suspect it runs along the same lines as the 41/400 thing.

Try a few loads and check for cratering and/or flattening. If using a semi-auto with a floating firing pin, chamber a few and eject and check for firing pin strike marks - make sure they're not going to ignite the round prematurely.

[Sandspider500]

CCI 41 thicker cup and more fuel


CCI 400

[kcheung2]

^ not sure what those pictures are supposed to illustrate since that’s a pistol.

[shamrock12]

[Sandspider500]

The difference in the compound. Yes, fired in a pistol, no powder, no bullet. Maybe they should have used a rifle with a 24" barrel for the test. I guess it's not obvious with the pictures

[NeilMo]

Sitting here with my friend Stevie Wonder, he sees what the pic illustrates

[cz74]

I would strongly advise against using CCI 400 with ball powders. It could cause dangerous hang fires which tend to be more common in cold conditions. Not to mention the CCI 400 has thinner cup thickness.

The CCI 450 has thicker cup thickness, and has the same thickness as the CCI 41.

Yep. I got hang fires with 6.5 Creedmoor using CCI 400 and Win 760, switched to CCI 450 no more hang fires. Watch Johnny Reloading Bench videos for more details.

[bergmen]

CCI 41 thicker cup and more fuel


CCI 400

Excellent comparison, thanks for the photos! Surprised at the demonstrated difference.

How did you trigger the camera?

Dan

[Sandspider500]

Excellent comparison, thanks for the photos! Surprised at the demonstrated difference.

How did you trigger the camera?

Dan

The tests weren't done by me, I found them while searching how to synthesize Lead Hypophosphite.

[bcrich]

I run 25g of H335 with CCI 400 primers & have never had a hang fire or click/bang or pierced primer but I do use CCI 41’s for my 5.7 because I have pierced 400’s in that particular load, however I don’t shoot in colder weather where the likely hood is far greater.