Primers

[6.5_fanatic]

What primers has everyone had the best results for loading the Grendel with?

[xlcc]

I have been using Remington 7 1/2 with good results.

[lrgrendel]

A lot of people get great results with the CCI 450 in their AR’s.

I am getting better results with the FED 205 M in my HOWA bolt action.

[Lone Hunter]

Haven't tried the Federal 205M yet. The CCI 450's are doing pretty good in the AR and the Howa Mini. The 210M do real good out of my .308

[Doon]

Was using WSR in my bolt guns, tried Federal 205 m and had better accuracy also.

[cb4017]

I've had great results with Tula SRM primers in the Grendel and target 5.56 loads. Unfortunately I don't think they are available any longer. When I use those up I'll start using the CCI #41s or 450 primers I have.

[6.5_fanatic]

So the magnum primers seem to give better results in the 6.5?

[cb4017]

An AR pattern rifle has a floating firing pin and will contact the primer on chambering. A magnum primer has a thicker cup than a standard primer (see chart) and is a little more insurance against a slam fire. A thinner cup primer may also show signs of pressure where you really don't have a problem.

[6.5_fanatic]

Thanks for the info. The attachment didn't show up though.

[LRRPF52]

Use the thicker cup SRPs.

I know at least one of the primer manufacturers recommends using thicker SRPs based on chamber pressure alone, even in bolt guns, for anything over 50ksi.

For AR15/M14 or anything with floating pins, use thicker SRPs.

Slam fire is just one aspect of it, loose firing pin aperture and firing pin tip dimensions are another.

When you have a larger firing pin aperture and a smaller firing pin tip, you're more likely to have primer cup flow around them (looks like cratering).

A thicker cup helps fight this.

[Sticks]

The CCI BR cups may be thicker, but I think they are softer.

I had concerns about flattened primers, so I swapped out some factory loaded powder and bullet into a sized and primed case, and still show signs of flattening.