Any feedback as to some of the techniques would be greatly appreciated.
I am going to be using Norma 300wsm brass, and berger 7mm 180vld.
Thanks
I am going to be using Norma 300wsm brass, and berger 7mm 180vld.
Thanks
Re: Necking down a 300wsm to a 7mm-300wsm?
One pass thru the sizing die with good lube ought to form the case. Problem maybe/maybe not is that when you size the neck down, it thickens and shortens a bit. If you can get the internal neck diameter of your new chamber from your gunsmith, form your new brass and seat a 7mm bullet then mike the outside of the neck with the bullet seated. You need about .002 on each side to allow for expansion and release of the bullet. If you don't have that much or more, you'll need to outside neck turn the brass to allow expansion. Then trim to length as your new brass allows. JMHO
One pass thru the sizing die with good lube ought to form the case. Problem maybe/maybe not is that when you size the neck down, it thickens and shortens a bit. If you can get the internal neck diameter of your new chamber from your gunsmith, form your new brass and seat a 7mm bullet then mike the outside of the neck with the bullet seated. You need about .002 on each side to allow for expansion and release of the bullet. If you don't have that much or more, you'll need to outside neck turn the brass to allow expansion. Then trim to length as your new brass allows. JMHO
Re: Necking down a 300wsm to a 7mm-300wsm?
Suggest Imperial sizing die wax (lightly applied), don't jam them through the die. Just smoothly size them down, trim to length, deburr, and run a brush through the neck. just finished 500 of the Norma brass, didn't lose any, good lot of brass.
Try RL25 and H4831SC with mag primers and put the Bergers into the lands a bit.
Suggest Imperial sizing die wax (lightly applied), don't jam them through the die. Just smoothly size them down, trim to length, deburr, and run a brush through the neck. just finished 500 of the Norma brass, didn't lose any, good lot of brass.
Try RL25 and H4831SC with mag primers and put the Bergers into the lands a bit.
Re: Necking down a 300wsm to a 7mm-300wsm?
Do you mind listing the specific dies that you used.
Thanks
Do you mind listing the specific dies that you used.
Thanks
Re: Necking down a 300wsm to a 7mm-300wsm?
I use a 7mm WSM Hornady full length die for case forming and Redding competition dies for neck sizing and bullet seating.
My rifle has a tight neck so I must also turn the necks, which is a whole extra list of steps
I use a 7mm WSM Hornady full length die for case forming and Redding competition dies for neck sizing and bullet seating.
My rifle has a tight neck so I must also turn the necks, which is a whole extra list of steps
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