Which SRP?

[mkk]

I'm going to put together a 500-600 yard AR in .223 Wylde. Primers on hand

CCI 400
CCI 41
Remington 7 1/2

Which one?

 

[idcwby]

Whichever one gives you the best accuracy.

 

[RegionRat]

Can't go wrong with those choices.

A test will show you the way. I like the 7 1/2 but some rigs will be different.

 

[MagnumManiac]

Personally, my results have always shown a preference for 205's in .378" case heads, and Winchester Magnum SRP's in .308" size cases, however, this has changed with powder type used.
I like Remington, they are soft and show nice start pressures, however if I waited on getting them, I would probably die first…

Cheers.

 

[Turpentine21]

I really like Federal 205 AR primers. I get good SD numbers with them. But then I prefer Federal primers across the board, except for shotgun. The CCI 41s are pretty good too but I don't get numbers that are as consistent with them. I can't speak for the Remington primers. I've never used them.
As said above, I let the rifle pick the primer if I have a selection. Whichever is most accurate and gives the best stats.

 

[Frank in the Laurels]

..no one can answer that question, a piece of paper will.

 

[sierracharlie338]

I've had good luck with the 400s over the years. Consistent across lots and never found them to be less accurate than any of the others.

 

[Pdyson]

All are good, but I was partial to the Fed 205 and recently I've been using the new Fed 205 AR which is another good one.

 

[biednick]

I'd skip the 400s in an AR. They have thinner cups than 41s. I've had issues with severe cratering well below max in ARs with them, and piercing in other guns that do just fine with 41s or 450s. There's a few factors that play into it, but in my opinion the best option is to use the thicker primers and not worry about it. I haven't used 7 1/2s.

 

[fmuguira]

Biednick gives good advice. Shoot 3-4 groups with the 41 s and the 7 1/2 s ….. then the rifle will give you the answer to "which" !

Enjoy the exercise

 

[Coyote Shadow Tracker]

CCI BR-4 and Fed Match GM250

 

[QuietTexan]

Out of those three, Rem 7 1/2s.

But Fed 205 GM ARs or CCI-450s are better IMO.

41s are and I use a lot of them, just not really necessary if they're priced at a premium. I've never once had a slam fire in an AR, even though pretty much every primer shows a dimple if the bolt is dropped on it. If the pin channel in the bolt is clean very little risk there.