220 WBY Rocket Fire forming

[WiseOldYote]

I have been working on this 220 Wby Rocket for a coworker. A resurection project of sorts. I was able to get a set of dies. There is no forming die I have found available. So I have come to the conclusion I need to fire form the cases from 220 swift brass. It shouldnt be that big of deal but need some advise.

Should I just load up a standard 220 swift load and use it?
OR
Use a very conservative load off 220 swift data?
OR
other recommendations.

Brass is new remington 220 swift.

Should I anneal the cases once fire formed for longevity or will anealing be necessary?

Thanks

 

[witchhunter]

I load for an Ackley Improved Swift and I use my old Swift loads to fireform brass. It is accurate too. I used 40 grains of 4064 for years, and this load still shoots well for fireforming. I end up with H380 for loads though. I don't think there is much difference between the Rocket and the Ackley. I reamed mine out just to keep the brass from stretching into the neck like the standard Swift does.

 

[WiseOldYote]

I tried 38gr of 4350 and 52 gr speer hp for initial fire forming and obviously wasnt enough powder. should I just step it up a bit and go with 41gr an try from there? fired case has very rounded edges around the neck. I have reservations about this new brass taking shape with one fire forming. Needing advise

Thanks

 

[steveno]

if you can find a copy of "Handloader" magazine #225 , October 2003 it has a pretty good article on loading for the Rocket

 

[witchhunter]

Use the same load a second time, the neck should get better. If you are not seeing pressure signs, go up a half grain until you do. When I was working up fireforming loads, I got lucky and the old Swift loads were very accurate.

 

[lightning]

The 220 Weatherby Rocket can be formed by shooting normal Swift loads. It head spaces properly. You may loose a couple 100 FPS but accuracy does not suffer.
The Rocket shoulder and neck is supposed to be a double radius curve unlike the sharp Ackly improved. Roy liked curves.

Been shooting mine since 1978 when Huntington's did the re-chamber.

Never have to trim brass since except to even the mouth. Neck size after forming if firing in the same rifle. I can get 5-6 loadings without annealing then the necks get brittle.

My load is XX gr H380 with Sierra 52/53 HPBT Match. 4000FPS. IMR 4064 works good but it's a pain to get extruded powder in that little neck. If you are interested PM for XX.

Ruger M77V circa 1977. 26" bull barrel. $198.00 new. I miss those days

 

[WiseOldYote]

Would anyone out there have a copy of that magazine they would like to scan the article to share?

Thanks for all the help/advise guys!

 

[witchhunter]

Yup, H380 and IMR4064 seem to work the best in mine too. I started out with a tang safety 77V in .220 swift. Still one of the most accurate rifles I have ever owned.

 

[lightning]

This is what mine looks like.