Peterson vs weatherby/norma brass for 257 Wby

Mike D Texas said:

I prefer Weatherby head stamped brass for my 257 Weatherby. I can consistently run 115 Bergers at 3600fps in a 25" barrel and still get multiple firings from it and print consistent 1/2" 5 shot groups as well.

Pretty cool to punch clean holes through 3/8" AR500 at 200 yards too.

View attachment 637830

Click to expand...

Your steel plate was bleeding...

Following

I have used the Weatherby/Norma brass in 6.5-300 and 300 Weatherby with no complaints. I've run the 6.5-300 really hard and after five firings, primer pockets are still tight. I've used both Peterson and ADG in other cartridges and found them to be likewise excellent. I plan on using Peterson in the future.

Pricing on 257 Wby brass is all other the place. Midway charges $94 for 50 Norma cases and $125 for the same quantity of Weatherby head stamped brass. Go figure. They are showing $109 per 50 Peterson cases with an availability date of 8/7/25. If you can wait until August, I'd go with the Peterson. If you are looking for some factory ammo to shoot for brass, Scheel's has 100 grain Interlock SPs for the same price ($65) as 20 prices of unprimed brass. That seems like a no brainer to me.

Somethin seems up with the 3.7-3.9.. numbers there. The bullet would be hangin out of the case for those lengths enit.??

I ran Weatherby n Norma stamped brass in my 257 n got 10 loads on all before pockets got too loose.
Also ran them in the 6.5-300wby and had good life there as well.

I hear/read now weatherby gets brass from whoever and wont say who makes what so this may affect things for the factory stuff.

I'm running weatherby brass in mine and it's ok but would definitely do Peterson if or when it comes out. I have one that's running 3886fps with the hammer 90gr
Have one that's running 4160fps with the same 90gr both with h4350.
26-28" barrels

The 90 has been great for everything I've hit with it. Not thing goes far usually straight down like it was struck by Thor.

FEENIX said:

My .257 WBY has a 1:7" barrel specifically built to propel the heavy/high BC bullets. I am experimenting with different powders (pressure testing) with the 163 Chinchaga. I am currently using Norma but will transition to Peterson when they become available.
View attachment 637831

Click to expand...

Holy smokes I didn't know chinchaga made such a long quarter bore!

The gun I bought is used and I plan on re barreling it in a year or two to a fast twist so any info you get on that would be useful to me in the future. For the first barrel I'm gonna push my limits of velocity with some of the light weight bullets, but once I get a new barrel I'll be switching to the heaviest I can find. Before you mentioned them I figured it would've been the 130 ish grain Bergers. But 163 sounds awesome!

Rifleman97 said:

Awesome that's great info. Can't see the top labels but I'm assuming that the 3.795 and 3.957 is COAL. That seems really long given the short bullets and long neck of the bee, is that just chasing the lands with the long freebore, or was there another reason you had for seating so long?

Click to expand...

Here are pictures....

Rifleman97 said:

Holy smokes I didn't know chinchaga made such a long quarter bore!

The gun I bought is used and I plan on re barreling it in a year or two to a fast twist so any info you get on that would be useful to me in the future. For the first barrel I'm gonna push my limits of velocity with some of the light weight bullets, but once I get a new barrel I'll be switching to the heaviest I can find. Before you mentioned them I figured it would've been the 130 ish grain Bergers. But 163 sounds awesome!

Click to expand...

Yes, and the 180 is coming out soon.