Switching to Magnum Primers

[Hschweers]

X bolt hells canyon 24” 6.5 PRC

Lapua Brass
140gr Nosler Custom Competition .035” off lands
H1000

I’ve been using WLR standard large rifle primers and 59.0gr of H1000. I recently found some CCI 250s locally, so i figured I’d give them a shot. How much should I back off to start working back up with a mag primer? I’ve only worked up to 59.0gr with standard LRPs and am not at pressure. I’m right at 3000fps and am happy with the groups so I haven’t chased more.

Velocities with standard LRP:
59.0 = 3,000fps
58.0 & 58.5 = 2960fps
57.5 = 2940fps
57.0 = 2840fps

Do I need to go back to 57.0? Is 57.5/58.0 a safe starting point?

Thanks in advance.

 

[Legend]

Where are you located? Might be easier to trade for large rifle primers.

 

[Hschweers]

Where are you located? Might be easier to trade for large rifle primers.

I still have about 700 WLR…. Just like to tinker

 

[Tahoe1305]

Shoot one or two at 57. If it’s the same velocity I’d accelerate back up quickly to your WLR loads.

 

[A382DWDZQ]

Shoot one or two at 57. If it’s the same velocity I’d accelerate back up quickly to your WLR loads.

This

 

[Weldor]

In the same boat, started at the bottom and worked up. No pressure signs at my old load , but I'm not shooting max load. Got the 129's worked out just need to work up my 140's. Loaded 2 ea. and shot them out of a cold chamber. Takes forever but is worth it. Using IMR4831, Nothing else available around here. Would love to get ahold of some rl 26

 

[Hschweers]

Shoot one or two at 57. If it’s the same velocity I’d accelerate back up quickly to your WLR loads.

I hate not being able to load ahead of time, but oh well! Guess Sunday’s trip will just take a little time. Thanks!

 

[t_carlson]

I'd back off at least 2 grains and work up again, but I'm not a hot-rod handloader.

 

[Flea21]

X bolt hells canyon 24” 6.5 PRC

Lapua Brass
140gr Nosler Custom Competition .035” off lands
H1000

I’ve been using WLR standard large rifle primers and 59.0gr of H1000. I recently found some CCI 250s locally, so i figured I’d give them a shot. How much should I back off to start working back up with a mag primer? I’ve only worked up to 59.0gr with standard LRPs and am not at pressure. I’m right at 3000fps and am happy with the groups so I haven’t chased more.

Velocities with standard LRP:
59.0 = 3,000fps
58.0 & 58.5 = 2960fps
57.5 = 2940fps
57.0 = 2840fps

Do I need to go back to 57.0? Is 57.5/58.0 a safe starting point?

Thanks in advance.

Id definitely back off to be safe. I use QuickLoad for my load development and save the printouts and keep a binder with records on the rifle so I know what I did last and if there is something I should do different next time... Im a little OCD obviously, LoL.

Let me know if I can help out by running some data through QuickLoad for you with your component changes.

 

[4cMuley]

Aren’t WLR known for being a bit hotter than others large rifle primers? (Cci, federal)