Hey Folks,
I am planing a 20PPC for benchrest competition. I have done quit a bit of homework but still have a question or two.
What I want is a tight neck 20PPC that alows me to turn case necks, comparable to a .262" neck on a 6PPC. Todd Kindler in his book "Terrific Twenties" built a no turn neck 20PPC with a custom reamer that measured .237. When I called Shilen for the specs on their 20PPC reamer, I was told it has a .229 neck.
From my calculations a .204 bullet plus 0.025 equals .229, equaling 12.5 thousands case neck thickness.
First question is what is the case neck thickness of new Lapua 220 Russian brass?
Second question is how much smaller should my neck be compared to the chamber? If the chamber is .229 what should a loaded round be? .228?
I guess what I'm asking is .229 a tight neck, and how much will have to turn off new Lapua 220 Russian brass, if any?
The other part of my question is concerning freebore. The Shilen reamer has .010 freebore, which I was told is SAAMI spec. I want to be able to set my seating depth for a jam fit like the 6PPC. With .010 freebore what lenght of bullet can I shoot? Will I be able to get a 35gr Berger into the lands, or will I have to shoot a longer bullet to get into the lands?
Thanks in advance. Any comments appreciated.
I am planing a 20PPC for benchrest competition. I have done quit a bit of homework but still have a question or two.
What I want is a tight neck 20PPC that alows me to turn case necks, comparable to a .262" neck on a 6PPC. Todd Kindler in his book "Terrific Twenties" built a no turn neck 20PPC with a custom reamer that measured .237. When I called Shilen for the specs on their 20PPC reamer, I was told it has a .229 neck.
From my calculations a .204 bullet plus 0.025 equals .229, equaling 12.5 thousands case neck thickness.
First question is what is the case neck thickness of new Lapua 220 Russian brass?
Second question is how much smaller should my neck be compared to the chamber? If the chamber is .229 what should a loaded round be? .228?
I guess what I'm asking is .229 a tight neck, and how much will have to turn off new Lapua 220 Russian brass, if any?
The other part of my question is concerning freebore. The Shilen reamer has .010 freebore, which I was told is SAAMI spec. I want to be able to set my seating depth for a jam fit like the 6PPC. With .010 freebore what lenght of bullet can I shoot? Will I be able to get a 35gr Berger into the lands, or will I have to shoot a longer bullet to get into the lands?
Thanks in advance. Any comments appreciated.
