I'm looking for some reference data on .35 Newton fireforming loads. I'll be using 250-300 gr. bullets and have lots of .338 WM, .358 Norma, & Hirtenberger 8x68s brass. My initial idea is to use 4350 or RL19 to fireform, but a friend suggested 4064 or 4320. I would be grateful to learn what fireforming loads other Newton shooters use.

Hey Strawboss,

Want to trade some of that 358 Norma brass ?

Chronograph data on an original Buffalo Mewton rifle done in 1971 pushed a 250 gr Hornady out at 2664 fps with 76 grs of IMR 4350 and CCi 250's. The brass was WW .338 WM.



The .35 Newton has a base diameter of .522" and the .338 is only .513" Those expansion webs did not look that good at all. Thus I would use the 8-68 brass. Its a bigger case than the .338 WM so that data would be fine to fire form with.



Thats a beautiful cartridge and far superior to the tiny 9.3-62 and a better design than the .375 HH. To bad it did not prevail.

Jimmy Mac: Sorry, but I just got a few .358 Norma's loaded with Woodleigh 250s on closeout from Graf's and don't have enough to share. When I measured the brass and tried to get more, it was all gone.
Savage 99: You're right about the .338 brass, but my reamer is cut a little tight at the base to compensate, but I agree, the 8x68s brass is a better basic case for this application. Huntington's rejected a shipment last fall and should have more available in the near future. I really like Hirtenberger's 8x68 brass and even contacted them in Germany trying to get more. They were extremely nice about it but said they were re-evaluating their product line and might not make more. So maybe RWS brass willl be available. Thanks for the info!