I just fireformed 5 rounds of brand new Peterson straight 284 winchester in my rifle that has previously shot only Lapua. The initial dimensions after fire forming are right on with the Lapua that is 8-10 fired as measured with a Whidden Gunworks chamber type tool. Both come in right at +0.001 (+/- 1/2 thou) from the zero mark. Sized the first piece with a Whidden 284 FL busing die that was set up for the Lapua brass to set back 1.5 to 2 thou. Lo and behold the Peterson set back 6 thou. Ran another piece of freshly annealed Lapua and it set back 1.5 as expected. Any thoughts as to why this might be? And along that line does this mean that I will likely have two different die settings based on the Brass manufacturer. As a note all of the Lapua has been annealed after every firing using and AMP annealer and the AZTEC code of generated off the specific lot of brass. Load is not hot at 50.1gr. H4350 running at 2750 FPS from a 30 inch barrel.
Sizing once fired Peterson 284 Brass
- Thread starter JPB4BAMA
- Start date
Sounds like the Peterson might be softer than the Lapua. Doug
r0tt3n1
Silver $$ Contributor
It has been my experience that Peterson .284 brass is "softer" than Lapua, and had similar shoulder bump results like yours. Not too big a deal for me, I am using the Redding Competition shell holders and just had to use a different holder because the Peterson would "squish" more. I did not have to adjust the die itself at least...
No issues with the Peterson brass for me otherwise. But the brass life of the Peterson was (for me) a couple or so of firings less than the Lapua overall; 6 or 7 vs 9 to10 for Lapua.
No issues with the Peterson brass for me otherwise. But the brass life of the Peterson was (for me) a couple or so of firings less than the Lapua overall; 6 or 7 vs 9 to10 for Lapua.
End of life due to primer pocket loosening?
Yes. Within +\- 1/2 thou.
r0tt3n1
Silver $$ Contributor
No, in my case it was signs of head separation that were worrisome
It’s softer on top. Same thing with PRC brass. Adjust die/shellholder. Keep it pushing.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.