01-12-2015, 01:46 AM
Excellent project!
Absent contrary advice, the twist rates needed to stabilize bullets are pretty much the same whether bolt or gas guns. I am using a TC Encore with a 9-twist 18" barrel but have not yet tested bullets heavier than 130 grains. I expect to test heavier bullets in the near future.
Some prefer an 8-twist to be sure of stabilizing the longest bullets, especially when the barrel is less than 19 or 20 inches long.
With the swelling of lead-free bullet advocacy, there may be some advantage to going with the 8-twist if you want to use 140 gr-class bullets.
Absent contrary advice, the twist rates needed to stabilize bullets are pretty much the same whether bolt or gas guns. I am using a TC Encore with a 9-twist 18" barrel but have not yet tested bullets heavier than 130 grains. I expect to test heavier bullets in the near future.
Some prefer an 8-twist to be sure of stabilizing the longest bullets, especially when the barrel is less than 19 or 20 inches long.
With the swelling of lead-free bullet advocacy, there may be some advantage to going with the 8-twist if you want to use 140 gr-class bullets.