40 cal - Twist

[yule]

 I am planning to build another 40 cal this year. My plan is to shoot 275 - 300 grain bullets.

 What twist is working well for you 40 cal shooters?

 Thanks

[jims]

I would ask sw. He is a long time .40 shooter and has several I believe.

[sideshow]

Whats being offered for sale is primarily 13s to 15s . My 2 are in the middle with 1 in 14 .

[ronc]

You didn't say at what speed or distance you want to shoot those bullets so this is generic. Twist rate to me is also dependent on the type of bullets you plan to shoot and at what range. The more frangible the bullet, the slower I want to spin it for a complete pass through, which I prefer.

I have 2 40 cals that are 16" twist for shooting the 228HC Pittman at 2700 to 2850 fps that I have been pleased with so far. I believe faster twist rates make for more violent expansion and less penetration with this type bullet, all else being equal. With an all copper bullet I want a faster rate.

I have an 18 tw 40 cal that I will be testing this bullet faster next deer season. We have a few choices out there that should fit your needs. I hope this helps...

[ET]

Ronc

Keep believing that faster twists make for violent expansions or shrapnel affect. The faster a jacket bullet is spun the more centrifugal force is loaded unto the bullet. This force is unloaded through violent outward expansion. Many believe velocity is the culprit for violent expansion but they are only half right. Here a copper bullet shines because the centrifugal force does not have the dramatic affect as on a jacketed bullet.

[jims]

I have an RB PacNor .40 barrel. I think it is a 1 in 16 twist.

[sw]

It is 16

[thelongrider]

Take a look on Pittman Bullets website. He has a bullet weight to rate of twist chart and the velocities for the bullets he offers. It shows the twist rate of 14-16 works for all his bullets. It may help you to decide.

[yule]

Thanks for the input. Good info to consider.