Grain Weight Reduction Switching to Lapua Brass 6.5 PRC

[General RE LEE]

I've been using factory 6.5 PRC Hornady brass for my reloads and about to dip into some Lapua brass I bought. I've got a solid load of 57.5 grains H1000 with the Hornady brass. How much should I reduce the weight of the charge switching to Lapua if any? I read two tenths of a grain is about the difference when doing load development. I am in a velocity node at 57.5 grains so I don't think it would swing much.

 

[918v]

I would drop it half a grain and creep back up if necessary cuz Lapua has less case volume.

 

[straightshooter1]

I've been using factory 6.5 PRC Hornady brass for my reloads and about to dip into some Lapua brass I bought. I've got a solid load of 57.5 grains H1000 with the Hornady brass. How much should I reduce the weight of the charge switching to Lapua if any? I read two tenths of a grain is about the difference when doing load development. I am in a velocity node at 57.5 grains so I don't think it would swing much.

I would suggest you measure the volumes of both the Lapua and the Hornady brass to see just how much difference there really is for those particular lots of brass. The difference could be far apart or it could be very close to the same.

For example, my Hornady brass I have averages 68.8 grs H2O and my Lapua brass averages 68.6 grs H2O. For that .2 grs difference in volume, it's a difference of .1 gr less of H1000 for the Lapua brass than the Hornady brass. If it's a .4 gr difference, then .2 grs less of H1000. So, you see . . . it all depends on the volumes.

 

[30cal user]

i would drop a whole grain for fire forming the new brass, the more i shoot virgin brass the more i want to start low and not have clickers from one firing

 

[General RE LEE]

i would drop a whole grain for fire forming the new brass, the more i shoot virgin brass the more i want to start low and not have clickers from one firing

My accuracy node is 57.5 grains H1000 147 ELD-M 2940 FPS.

Not exactly screaming

 

[918v]

My accuracy node is 57.5 grains H1000 147 ELD-M 2940 FPS.

Not exactly screaming

By SH standards you’re shooting a Creedmoor

 

[Earnhardt]

By SH standards you’re shooting a Creedmoor

Yup...he is