CCI Primer question

[Laurie]

CCI 400 is safe for everything except maybe AR type rifles. The reason is that the firing pin in the AR is free floating in the bolt carrier, which could result in a slamfire. I have fired thousands of rounds in AR rifles and this has happened to me twice. The cause was a dirty bolt carrier causing the pin to become stuck. Cleaning fixed the problem. The armed forces decided to have a stiffer primer as in a combat situation there can be limited ability to clean it.

It's nothing to do with AR-15s. Early thin-cup CCI and Remington primers were designed for the original small primer rifle cartridge, the 1930s .22 Hornet which was both low pressure and saw many users adapt rimfire or other actions with weak firing pin strikes. When Remington introduced the .222 Rem cartridge in 1950 with its 50,000 psi MAP, it also introduced the first so-called SR 'Magnum' primer its 7 1/2 model which was deemed necessary to cope with primer extrusion and possible failure with the Triple Two's higher pressures. Although officially a 'magnum', it actually used the same explosive pellet as the thinner cup Rem 6 1/2. (It was later replaced by the 'hotter' Rem 7 1/2BR which was needed for reliable ignition in the .17 Remington cartridge in all conditions.)

The US Army requested less sensitive primers much later for the AR, the answer being the CCI-41 which is pretty well akin to the CCI-450 SRM in performance, but the 'anvil point' is placed further from the explosive pellet instead of nestling against it as is normal. This allows a small cup indentation to occur thanks to the free floating pin without pressing the anvil into the active compound risking ignition.

For a long time, Rem 6 1/2 primer sleeves bore a warning they were not to be used in any modern high-pressure cartridge such as .223 Rem. AFAIK, only Midway USA now prints this warning:

https://www.midwayusa.com/product/1601138078

 

[lawman29]

Never had any pierced primers in a variety of makes and shooting platforms.
I have used 61/2 in a 221 Fireball with no problem.

 

[Laurie]

Never had any pierced primers in a variety of makes and shooting platforms.
I have used 61/2 in a 221 Fireball with no problem.

Whether you 'get away with the practice' or not depends on two things - peak pressure, but more crucially usually, the size / shape / fit of the firing pin tip in the bolt face. A slack pin allows primer extrusion and ultimately failure at lower pressures than a small dia. pin that's a tight fit. In all cases though, the problem arises at lower pressures with the weak thin cup primers and is more likely to lead to 'blanking' where the cup fails and blows a disk out than in the 25 thou' thick cup models.

http://www.targetshooter.co.uk/?p=2621

http://www.targetshooter.co.uk/?p=2662

and in each case scroll down to the relevant pics and text on primer condition / failures. This was in a Stolle Atlas action with a better firing pin fit than in many factory Savage, Remington etc examples, but not perfect, with a full pressure load at probably just under 60,000 psi.

Whidden Gunworks and other gunsmiths including @Grimstod on this forum provide a pin-turning and bolt-bushing service to alleviate this issue. It was an essential modification for many who had 6BRs built on Rem 700 actions when the cartridge became popular in custom jobs a generation ago. For some reason I've never seen explained it affects small primers far more than large.

 

[Nick Caprinolo]

Laurie
Here in the US we mostly us Federal ad CCI primers. What do you think of other brands like Fiocchi, Genex and some of the other brands? There does not seem to be any discussion about any of them here.

 

[L.Sherm]

For a long time, Rem 6 1/2 primer sleeves bore a warning they were not to be used in any modern high-pressure cartridge such as .223 Rem. AFAIK, only Midway USA now prints this warning:

I pierced 6.5's in a 222 Rem mag about 17-18 years ago and switched over to 7.5 and never a problem.
I'm not in the camp to say 400's are safe in anything except AR's thats gonna depend on rifle and load.

 

[Laurie]

Never seen Ginex primers here, and Fiocchi are rare. During the last great components shortage 10 or so years ago when US made primers disappeared here, one of our dealers imported a big lot of Fiocchis, which I've found to be very good. Whether they'd match BR2s and F210Ms in precision loads I can't say, but I certainly see them as least as good as CCI-200s and better than Rem 9 1/2s and some others. (They come in 150-ct trays and 1,500-ct boxes and I ended with 7,500 LRs thinking I was buying my usual 5,000!) I've had more limited experience of their SR model and it seems 'a good one', no blanking issues either, so must be a thicker cup.

In recent years, we've very much survived on Russian primers, What was Wolf and Tula in the US is originally PMC, later 'Murom' branded here. The basic KVB-223 SR is too 'soft' for very high-pressure loads or AR use, but the rest of the range is superb. Many of our top 'Effers', both F-Open and F-TR use these primers in both sizes. I'd rate the KVB-7 and KVB-7M (magnum) LRs as good as the BR2s and F210Ms of some years ago when they were last available here. Both, including the magnum are very mild primers. As of late last year, imports were finally stopped by HMG on anti-Russian sanctions grounds which was a blow.

One of our importers receives Brazilian CBC Magtech 7 1/2s and 9 1/2s in the rifle versions and they're also good, the 7 1/2 outstanding in some cartridges and loads I've tried. Its cup is a bit 'soft' for AR use IME though.

Czech S&B was little known here until recently, but it makes excellent products - grab them if you see any! They've disappeared here recently - I suspect fallout from the Russo-Ukraine war.

PPU I've only ever used in penny packet numbers - they go bang reliably and appear to produce reasonable ES values, so can't say much more than that.

Viht once made primers and is restarting with supplies to handloaders from 2025, so that'll be interesting.

 

[K22]

It's nothing to do with AR-15s. Early thin-cup CCI and Remington primers were designed for the original small primer rifle cartridge, the 1930s .22 Hornet which was both low pressure and saw many users adapt rimfire or other actions with weak firing pin strikes. When Remington introduced the .222 Rem cartridge in 1950 with its 50,000 psi MAP, it also introduced the first so-called SR 'Magnum' primer its 7 1/2 model which was deemed necessary to cope with primer extrusion and possible failure with the Triple Two's higher pressures. Although officially a 'magnum', it actually used the same explosive pellet as the thinner cup Rem 6 1/2. (It was later replaced by the 'hotter' Rem 7 1/2BR which was needed for reliable ignition in the .17 Remington cartridge in all conditions.)

The US Army requested less sensitive primers much later for the AR, the answer being the CCI-41 which is pretty well akin to the CCI-450 SRM in performance, but the 'anvil point' is placed further from the explosive pellet instead of nestling against it as is normal. This allows a small cup indentation to occur thanks to the free floating pin without pressing the anvil into the active compound risking ignition.

For a long time, Rem 6 1/2 primer sleeves bore a warning they were not to be used in any modern high-pressure cartridge such as .223 Rem. AFAIK, only Midway USA now prints this warning:

https://www.midwayusa.com/product/1601138078

Very useful information - good job - thanks.

 

[451whitworth]

The first two issues of Handloader's Digest ('62 & '64) make no mention of SR magnum primers (either CCI or Rem 7 1/2). The 3rd edition from 1965 is the first mention of them.

 

[nmkid]

Nice discussions fellas.

 

[Eric Leonard]

I’m shooting enough lt32 in my 6ppc for 3410 fps using cci400s and have never pierced one and in fact the edges are still rounded,