6.5 PRC Load Dev - Did annealing change pressure?

[JM151]

In my experience, virgin brass will take a higher charge than when the case is once fired to achieve the same velocity. In other words, it's totally normal to have to reduce the charge after the first firing. If the charge is not reduced, pressure will be higher and as a result, so will the velocity. I think this is what you are experiencing. Has nothing to do with annealing.

And as other have stated, probably a good idea to go down at least a grain.

That’s good to know. I didn’t realize going from virgin to 1x fired would make that big of difference, but like everybody is mentioning I’m on the edge of pressure.

I’m probably going to disassemble my firing control so I can get accurate headspace and bump shoulder accordingly.

 

[BigDog00]

Was there a big difference in air temperature between the two range sessions? Not sure what the temp stability of N565 is.

 

[Jason Snyder]

In my experience, virgin brass will take a higher charge than when the case is once fired to achieve the same velocity. In other words, it's totally normal to have to reduce the charge after the first firing. If the charge is not reduced, pressure will be higher and as a result, so will the velocity. I think this is what you are experiencing. Has nothing to do with annealing.

And as other have stated, probably a good idea to go down at least a grain.

This. This. This.

 

[Shortschaf]

Yeah, never use virgin brass charge data.

 

[JM151]

Was there a big difference in air temperature between the two range sessions? Not sure what the temp stability of N565 is.

No. Both days around 80