Reloading 7mm PRC

[Countrykang8]

I'll be trying the Magnums with the N565 in the once-fired Peterson brass.

I am slowly transitioning away from magnum primers because I have experienced a few pressure spikes during hot temperatures here in Texas. No issues in colder temps, but I like to practice year around.

 

[Longtine88]

I have an 8lb jug of N570 and was curious if anyone has experience using this with some 180 class Berger's in the 7prc. The lack of information I've found online leads me to believe this combo is not worth pursuing. Any information is appreciated.

Compressed a little. Use a drop tube and it will work. I've tried it on 195's in the 7PRC and 7 Saum. Both work great with it. N568 also works well also but will be 40 to 60 fps slower. But It does work and works very well.

 

[Phil Rizzo]

Mine is happy with 568 and 190LRHT.

 

[Longtine88]

Mine is happy with 568 and 190LRHT.

Yeah that's a good combo for sure. I use it in one barrel

 

[Countrykang8]

Mine is happy with 568 and 190LRHT.

Sir, what your charge with N568. I just obtained a couple of pounds.

 

[Phil Rizzo]

Compressed ! But not maximum. Around 1-1.5 grs under max with .004 neck squeeze

 

[deputyrpa]

I am slowly transitioning away from magnum primers because I have experienced a few pressure spikes during hot temperatures here in Texas. No issues in colder temps, but I like to practice year around.

I ran these two lots just for you.
Both lots:
67.9gr N565
175gr ABLR
Once-fired Peterson Brass
2.640" CBTO
First 5-shot lot using White River Large Rifle Magnum Primers
Velocity average: 2832fps with ES=10 and SD=3.8

Second 5-shot lot using White River Large Rifle Primers
Velocity average; 2819fps with ES=21 and SD=7.7

Target set at 203 yards, no MOA adjustment on scope. Alternating shots. WR LR on right, Wr LRM on left.

 

[Countrykang8]

I ran these two lots just for you.
Both lots:
67.9gr N565
175gr ABLR
Once-fired Peterson Brass
2.640" CBTO
First 5-shot lot using White River Large Rifle Magnum Primers
Velocity average: 2832fps with ES=10 and SD=3.8

Second 5-shot lot using White River Large Rifle Primers
Velocity average; 2819fps with ES=21 and SD=7.7

Target set at 203 yards, no MOA adjustment on scope. Alternating shots. WR LR on right, Wr LRM on left.
View attachment 602857

The magnum primers produced much better groups and tighter fps.

 

[deputyrpa]

The magnum primers produced much better groups and tighter fps.

Yep. I just juiced up the load to 69.4gr N565 and it opened up again. I'm going to step down to 69.1gr

 

[Wy Will]

I ran some 160 monos with N565 at 71.5gr with an sd of 2.6 shooting 3179.6 fps for 2 separate 5 shot groups. Group was about .8 moa. I was using GM215M primers. Everything was pretty good, but I was at pressure and wanted to back off. I decided to try large rifle primers and also dropped the charge weight. Using GM210M primers and 71.0 gr of n565 got me 3088.2 fps and an sd of 4.4 for a 5 shot group. It was about a 1 moa group.

I'm going to try using the LRM primers at 71.0 gr for 5 shots and also try the LR at 71.4gr to see what I come up with and compare velocities. I'd be a lot happier if I was around 3/4 moa or less for 10 shots.

 

[Phil Rizzo]

Wouldn't pressure spikes be associated more with powder/temperature than the choice of primer?
I'd think so.
Especially if you are on the edge. Might not realize that part until the mercury gets up enough though.

 

[deputyrpa]

Yep. I just juiced up the load to 69.4gr N565 and it opened up again. I'm going to step down to 69.1gr

Oofa....69.1gr N565 was evern worse. about 1.5MOA