Forming 300 Ultra Brass from 404 Jeffery


Well-Known Member
Jun 20, 2001
I am thinking of buying a 3-die set from Huntingtons to form 404 Jeffery brass into 300 Ultra brass. The Remington stuff is very poor. I have ordered single cases from HDS, RWS, and Bertram. I will cut these up and play with them to get an idea of differences. I am hoping that the .539 rim will just fit into my Remington 700 bolt face of .541 and still function. I know that I will have to fire form my brass, and turn necks of course. But, what am I missing here? Who do you think makes the best brass for this? I would really love to hear some opinions.
A less expensive route would be to get redding form and trim dies in 375 and 338 ultra mag. Then run it through a 300fl die. Let the 375 set the head space and adjust the 338 so to just touch the shoulder. I used the 375, 338, 300, and 7mm to form 270x300ultra mag and it works quite well.
Thanks, TXHunter. What manufacturer of brass did you use. I take it you where not happy with the Remington brass either.
TXHUNTER, I had a fellow reply to me today on this subject. He said that due to the smaller base diam. of the 404 cases that I would not be happy with the results of fire formed brass in the 300 ultra chamber. Did you use a m700 action? If so, did you have any problems getting the 404 rim to fit into your bolt face or did you have a Sako extractor installed? Did you run into a sittuation where the base was to small? Do you think that the extra trouble is worth the better brass. If I can get better brass then it seems to be worth it to me. A 1/8" difference in group size at 100 would sure make things worth while or the ability to boost preasures a little higher.
Can't hepl you with wether they will fire form well or not. I too have given thought to the fact that the 404 will be a tad under sized, will just have to see. My rifle is still at the smith, haven't had a chance to shoot yet. I sent him 3 formed 404 cases to be test fired and expect to here from him pretty soon.
Yes it is on a 700 action and I did have a sako extractor installed.
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