6br freebore

[chomondely]

Lawton Machining is building a 6br for me. I am getting ready to spec the barrel and spec the chamber.
I am plan on shooting 70 to 90 grain bullets out to 300 yds. I am planning on either a 1/10 or 1/12 twist. I am concerned about using a reamer that seems to be set up for heavier bullets.
If I am using bullets less than 95 grains, how much freebore do I want?
Thoughts on twist?
Thanks for your thoughts.

 

[Preacher]

If your going to shoot under 95 grain bullets, the 10 twist should work, a 9 twist is what I would do, and set it up with a .070 free bore..... even if you used a reamer with a .110 free bore you would still have no problem with bullets under 95 grains.....

 

[chomondely]

Thanks, I'll probably go with a 1/10.
The reamer is set up with .10 freebore. Is that too much for short bullets?

 

[Toby Bradshaw]

Thanks, I'll probably go with a 1/10.
The reamer is set up with .10 freebore. Is that too much for short bullets?

If you want a reasonable length of the bullet's shank in the neck and still be able to reach the lands, then 0.100' is too long for most of the lighter 6mm bullets,and even too long for the Berger 95 VLD). A 1-10 with 0.100' freebore would work well with the BIB 95gr FB, though.

The ~0.100' freebore is the common setup for 105-108gr bullets in 1-8 twist barrels.

Toby Bradshaw
baywingdb@comcast.net

 

[chomondely]

.10 freebore seems a bit long. I'll see what else they have.