Forming .338-06 brass

[onlybrowning]

I have a a couple .338-06 barrels that I’ll be loading for. Neither are here yet, but I was hoping to get some brass sized in preparation for their arrival. I ran a couple of Starline .35 Whelen cases through the RCBS full length sizing dies and all went smoothly. I also tried a piece of .30-06 brass, with the die adjusted the same (ran the die down til it contacted the ram then another 1/8 of a turn or so). The part that I’m struggling with is the brass looks quite different to me. Without either of the barrels here, it probably makes sense just to wait, but I thought I’d post a picture here to see if anyone has any insight. Is there a piece that looks “better” or can you see anything that would lean you toward using the .35 whelen or .30-06 brass? .30-06 is on the left, .35 whelen on the right. The whelen brass is new, .30-06 once fired (I have new .30-06 Starline brass I could try as well).

 

[4570neal]

When I built mine I used 30-06 brass like you did and just fire form it.
Worked good. Used a Winchester action and a Douglas premium bbl. I was getting 2750 fps with 225 gr bullets and 4320 powder. Good luck and have fun!

 

[onlybrowning]

Thank you! I happen to have more brand new .35 Whelen brass on hand. Any reason not to go that route? Curious if you noticed anything problematic from the picture?

 

[RME]

35 Whelen brass is fine. Wait until you get the barrels then when you neck the cases down you can set up a “false shoulder” with a light crush fit. That way you’ll get a good fire form on the first firing.

 

[4570neal]

I agree with RME, the shoulder looks better on the Whelan case. And wait for the barrels.

 

[onlybrowning]

Thank you! I thought I liked the looks of the .35 Whelen brass necked down, but I wanted others to see it since they definitely look different to me. The only real fire forming I’ve ever done was for a couple different .30-30 AI’s in Contenders. With those, I just sized tve neck, loaded a moderate load and fire formed them.