Ar15 primers 556/223

[Uncle Ed]

Both the M14 and M16 rifles had there firing pin lightened during their trials period. This reduced their mass and inertia to reduced slam fires. Again the greatest chance of a slam fire is if a single round is loaded in the chamber without feeding from the magazine to slow down the bolt velocity. Also when the above report was written Remington was running Lake City and their 7 1/2 primer was being used in the 5.56 ammunition.

The above and the rifles history is written in the book below.

 

[Rsadams]

I agree , I have never had a slam fire with any ar15 and regular CCI S/R primers that are seated correctly... Mine doesn't dent the primer really at all of course i keep mine clean... Now my SKS dents them scary bad even after cleaning the crud out of the bolt.... Just be aware that it could happen...

 

[dcali]

I use the 41s just because I'm paranoid of slam fires.

 

[Ksmirk]

I use titanium firing pins, lightens the mass and don't even get the little dinks on primers.

 

[Rsadams]

I use the 41s just because I'm paranoid of slam fires.

They are so expensive here , you can get br-4 for that price and they have the same thickness cup... I have never seen the 41s on sale either.... I always figured the 41s were just 450s repacked... But they are good insurance if your rifle dents primers and some ARs do...

 

[dcali]

They are so expensive here , you can get br-4 for that price and they have the same thickness cup... I have never seen the 41s on sale either.... I always figured the 41s were just 450s repacked... But they are good insurance if your rifle dents primers and some ARs do...

I'm not sure if the commercial version is the identical, but the 41 primer is an actual military spec, not just a CCI model number. Whether or not they're the same as 450s is anyone's guess. 450s are silver colored, right? the 41s are gold. That's probably why they cost more.

 

[Rsadams]

I'm not sure if the commercial version is the identical, but the 41 primer is an actual military spec, not just a CCI model number. Whether or not they're the same as 450s is anyone's guess. 450s are silver colored, right? the 41s are gold. That's probably why they cost more.

Lol , it must be.... They are good insurance but they are expensive... I bought a bunch of CCI S/R when I first started reloading years ago and that's why I use them still.... I have never had a problem other than them flattening easy but I also point the rifle down range before chambering the first round just in case because I was told years ago about the possibility of slam fires... If I was shooting a scope instead of iron sights I would go ahead and use some br-4 in them but the iron sights limit accuracy for me because I can't see the front sight so good anymore.... I have read were the 41s , 450 and br4 are all the same thickness...

 

[searcher]

Those BR4 primers are fine. They are great primers and while they have the desired toughness for A/R's, they don't fit as tight as a lot of guys need after several firings - depending on how warm your loads are and which brass you use. And that is the only downside which, for a lot of people, is non-existent as they toss brass after four or five (or two) firings. For best pocket fit (especially if reaming mil brass), use Tula or Wolff .223 Mag or .556. Rem. 7 1/2 next best. The CCI 41's and Federal A/R Match rounds it out. Personally - I'd not use any primer in an A/R other than one of these five and maybe one or two others others way down the list.

 

[fatelvis]

Does anybody know the outside diameter measurement of the 41’s cup? It’s not in the chart.

 

[m1jeff]

Here ya go

http://radomski.us/njhp/

 

[Mad_Charlie]

Here ya go

http://radomski.us/njhp/

Look in "Reloading Stuph".
Some good info over there in general.

 

[m1jeff]

Sorry, I thought I copied the direct link

 

[Mike7.62]

Ditto the CCI 41's in the AR; also the CCI 34's in M1's and M1A's.