Where to go from here?

[aarolar]

I want to shoot cast in my 358 Win at full power velocities. First I know I need a chamber cast but where do I go from there? I shot some groups today using a 35-200 over 43 grns of IMR 3030 that were averaging 2300fps. These were grouping anywhere from 3 to 4" at 100 yds with zero leading even after 20 or so rounds, acceptable to me would be 2" max. Just checking my once fired brass it appears I may need around a .360 boolit to fit my throats and I'm more around .3585. My RCBS mold drops .359 using my 3-1 alloy which is essentially WW alloy.

I know I have to fit the throat and it appears that is going to be impossible with my mold so I guess I need to look custom. Going to check tomorrow for a piece of 5/16 rod so I can do a pound cast. Anyway I'm just rambling and looking for input.

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[Larry Gibson]

12" twist?

[Texas by God]

Aarolar, try some jacketed loads to establish an accuracy baseline and to polish the bore a bit.
Several members here know a lot about pushing boolits to high velocity. Perhaps someone will chime in with pointers.
Best, Thomas.

[aarolar]

12" twist?

Yes sir.

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[aarolar]

Aarolar, try some jacketed loads to establish an accuracy baseline and to polish the bore a bit.
Several members here know a lot about pushing boolits to high velocity. Perhaps someone will chime in with pointers.
Best, Thomas.

I hesitate to shoot jacked bullets in it at all, the goal for me was to stick with cast entirely. I may break down and try some eventually but I want to try and stick it out.

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[aarolar]

More ramblings, I feel my wheel weight alloy is going to be too soft at these velocities in respects to expansion and meat damage. An alloy with more antimony should yield a larger diameter as cast too right? I have 7 lbs of Lino I think I may cut it with 7 lbs of pure and see where I end up.

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[aarolar]

Finally got around to the pound cast and here is what I got could someone please help me interpret it. Can't accurately measure bore size due to three groove rifling.






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[gpidaho]

aarolar: To measure slug sizes when there is an odd number of grooves I like to use sizing bushings as sold by NOE (I have a rather large collection) Then it's just a matter of sliding the slug into the sizing hole until you find which one fits. I tried the old wrapping the bullet with thin aluminum strips trick but I'm too fumble fingered to get the same number twice. lol Gp

[gpidaho]

also we would need the brass thickness of the neck of the cartridge above to help you out with measurments.

[aarolar]

also we would need the brass thickness of the neck of the cartridge above to help you out with measurments.

Appears to be approximately .012 thick.

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[gpidaho]

Something wrong with the measurements somewhere. If your bore is truly .3594 then your bullet should be sized .360. With the OD of the case neck @ .391 and a neck thickness of .012 that would make your bullet .367 so there seems to be a .007 error in measurements somewhere. Gp

[buckshotshoey]

I had a similar prob in 45- 70. I lowered the powder charge a bit, and started water quenching my bullets (100% wheel weights). Problem solved without changing my alloy.