Prepping The Cases
My wife wanted me to try and shoot a few seal this summer when I am out on the Kuskokwim River here in Southwestern Alaska. I cannot do this according to the Marine Mammal Protection Act of 1972...but she can as she is 100% Yup'ik Eskimo. So for her upcoming birthday, I bought her a Winchester Model 70 in .223 WSSM.
I purchased 100 cases of Winnie brass, and Wilson arbor press style dies, Redding body and full-length dies and an assortment of projectiles from Russ Haydens Shooters Supply. I thought I would create the most consistent cartridges I could to see what the rifle is capable of.
I inspected the cases and seperated 18 because the primer flash holes are oblong. I trimmed the remaining cases and reamed the primer pockets and de-flashed the flash holes. I then ran all through the body die, which did nothing. Then I ran them into the full-length sizing die to squeeze the neck down, opened them back up with the K&M expander mandrel and began turning the necks (to say these cases are thick necked is an understatement; most of the neck-wall thickness are 0.021" without much variation). I found only 6 cases that fit tightly on the neck turning mandrel the rest were too loose, so squeezed them back down and put the expander mandrel in a drill press to remove some material. I measured the mandrel at 0.2245" exactly with my Starrett micrometer. I used 600 grit sandpaper and then polished with 1500 grit. Final diameter is roughly 0.2242". I didn't think it would make much difference, but it is enough the cases are tight, and not wobbly on the turning mandrel.
I am removing 0.0015" of neck for a neck-wall thickness of 0.0195". I finally have the 85 good cases done and am glad of it; my wrists hurt.
I have started priming the cases with my new K&M Primer Seater with dial indicator. This neat piece of machinery measures each primer so you can zero the dial indicator, then when seating said primer, when the indicator reads 0.000", it is just touching the bottom of the pocket. Squeeze just a little more for preload and it's done. So now all my primers are seated with excellent consistency. Yes, I wanted to go all the way on this project.
To establish my chamber length I inserted one of the 53 grain Barnes TSX bullets long into a case then chambered it. From base-to-ogive it is 1.836", compared to a couple of Winchester factory rounds at 1.775". That 0.061" off the land surprised me. But then again this is the first time I've done anything with a .223 WSSM.
Time to pack everything away as the wife is coming in on the afternoon flight and I don't want her to see all this gear on the kitchen table.
Once I start loading, I think I will set the seater die to 0.010" off the lands using beginning loads and work from there. I'll have to wait for the river to break up first before I can do any shooting though.
So far it has been a bit a work, but I find it very relaxing after a day at the office. I only hope this rig shoots as well as the time I've invested in the cartridges
You may want to consider seating the TSX's a bit further off the lands. Barnes recommends .030 to .070. I've found .040 to .050 to be most accurate in my three guns.
+1 with Kay9 and check your rounds to be sure that they fit into your magazine. Sometimes the magazine length is the limiting factor in OAL in WSMs and WSSMs.
Thanks. I think I will use three-round groups to start at 0.050" and then work forward. I'll use lower than beginning loads so I am unconcerned with pressure.