223/556 Primers

[bmitch300wby]

Good morning. I have a few questions about using CCI400 primers in 556 brass. I've been told you must have a military primer or CCI No. 41 primer. I've loaded plenty of rounds using 400's in Winchester brass but not in Lake City brass. Any recommendations? Also, I have a box of CCI 550 small pistol magnum primers, has anyone used those while loading 223/556? Thank you for the info.

[Slamfire]

It really depends on what mechanism you are shooting these rounds in, and your tolerance for risk.

You did not mention the rifle, but I am going to assume that it is not a bolt rifle. I am of the opinion that you can use any primer you want in a bolt rifle and all you have to worry about is primer piercing.

Slamfires happened to the early M16’s because of a heavy firing pin and sensitive commercial primers. If you look in Chapter eight, page 130, of the “Black Rifle” by R. Blake Stevens, there is an entire section on the slamfire problems the Army had with the M16. A number of AR15 slamfire incidents had occurred when cartridges were single loaded and the bolt release pressed.

If you read the report in the book, dated 1963, based on the tests of two rifles with the firing pin configuration available at the time, the energy during bolt closure of one of the test rifles firing pin always was above the “none fire” specifications of the primer. Which meant that statistically some of the primers would ignite at those energy levels. So the Army did two things. They lightened the firing pin and they changed the ammunition specifications to require a less sensitive “harder” primer.

Original M16 firing pin on top.



Look at the Fulton Armory FAQ, the article “Slamfire: the M16 story” http://www.fulton-armory.com/faqs/AR-FAQs/SlamFire3.htm

You can find the official, originally classified history , here:

Report of the M16 Review Panel Appendix 4 Appendix 4 Ammunition Development Program

http://www.dtic.mil/dtic/index.html

Unlike the M1 Garand, M14, M1a, M1 Carbine, and Mini 14, all of which have many in battery and out of battery slamfires, I have found only one credible account of an out of battery slamfire in AR15’s and many accounts of in battery slamfires with sensitive commercial primers. For the AR15 mechanism, it is best to use primers that are “mil spec” in sensitivity as it reduces the risk of an inbattery slamfire. This is a video example of an inbattery slamfire:

Tavor 21 Slamfire video

http://www.youtube.com/watch?v=_cv7BI3wGWA

Notice how many rounds the guy fires. If he had a mechanical problem he would have recurring slamfires, but he did not. When you see the slamfire, notice that the finger is not on the trigger. He was running Federal American Eagle (federal primers) and Winchester ammo. Winchester redesigned their primers in 1999 to make them more sensitive.


You can examine your primers and on every AR15 round I have ever chambered there is a dimple from the firing pin rebounding off the primer. Given a sensitive enough primer, the round will fire. The unfortunate fact is, primers vary by sensitivity, vary by sensitivity within the lot. The mil spec primers give the least risk of a slamfire, as the average lot is less sensitive than commercial primers, but have no doubt, due to the uncertainties of manufacture, overly sensitive mil spec primers do make it out the door of the factory. Never chamber a round, in any mechanism with a free floating firing pin, under the assumption the rifle cannot not discharge.

CCI 400 are good primers, lots of people use them, they are still commercial sensitivity primers.

This is a good reference on primers:
CHOOSING THE RIGHT PRIMER - A PRIMER ON PRIMERS

http://www.sksboards.com/smf/?topic=56422.0

Also, I have a box of CCI 550 small pistol magnum primers, has anyone used those while loading 223/556?

Pistol primers are best used in pistols. Cups are probably thinner, and once you dish a firing pin tip with a pierced primer, you will figure out that thinner is not better.

[Steve in PA]

I've been reloading and shooting .223 ammo for my AR since 2006, using nothing but CCI 400 primers.

[fct10]

I have loaded nearly a thousand rounds using CCI magnum primers. They appear to be very similar to military grade (thicker).

I use light to medium loads and never have any cycle problems with PSA AR-15.

Supposedly these primers are hotter than standard small rifle primers so use good load procedures (load light and work up).

Small pistol primers might work but you may run the risk of piercing one with a rifle. Probably not worth the risk.

[Stavman11]

basicaly nothing but CCI400's in Thousands of my AR loads... Now recently I expanded to Tula and CCI450 due to availability and so far all have shot flawless

CCI400 are Fine...

[tobnpr]

CCI is generally regarded as being hard "enough" for use in semi's...
At least that's what my research bore out, and I've run thousands of 450 Magnums through a 6.5 Grendel without a hiccup.

[newmexicocrawler]

I have not had any problems with any primers I have used

[bmitch300wby]

Thank you all for the info. I tried several rounds I loaded with Lake City brass using CCI 400 and it worked fine. I'm not so inclined to try the small pistol magnum primers for 223. Now the hard part...... Finding powder ......

[MtnCreek]

^

http://www.butchsreloading.com/shop/...-tac-1lbs.html

http://www.brownells.com/reloading/p...-_-Custom+Link

[totalloser]

I read recently (reference was cited) that the CCI magnum pistol and small rifle are the *same* primer different packaging. #41 military "hard" primer is obviously different. I have only loaded #41's, but I would not fret over using regular small rifle.

Now having said that EVERY SEMIAUTO with EVERY primer should be treated as a possible slam fire when you chamber. I do not treat my rifles any differently with #41's- I assume it may fire on chambering no matter how unlikely. Sort of like having a hot barrel cookoff- always tend the barrel in a safe direction. It may be highly unlikely, but so is the lottery and someone eventually wins it.

[MtnCreek]

I use CCI Mag SPP's in 9mm HS6 loads and fire them through a few different pistols. I'm having a hard time believing a striker fire pistol like a glock would give the same or even close to the same pin force as a rifle.

I have heard several people say the CCI SRM primer is the same or close to the Mil primer. But I'm just repeating what I've heard.

[bledsoeG19]

From what I read, tula srp's are said to be a harder primer than others.

And they're less expensive.

[Stavman11]

From My experiences the Tula seem harder and slightly Larger Than CCI Primers

For my older 3x Plus loaded cases I usualy use the Tula... they seem ta be snugger on older Cases... On newer and 5.56 cases Ill use CCI primers for the 1st couple reloads.... since they are easier to seat on a Reamed out Primer Pocket...

works well for me