• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

what should .223 freebore using berger 70gr vld

I'm building a tube gun .223 Rem. 1 in 8 twist 27" barrel. I will be shooting Berger 70gr vld & 75 gr vld
mostly shooting 300-600 yards. I need to know what the free bore should, I'll be loading .010-.015 off lans.
I don't want to get to long and have concentricity problems, and not to short to have pressure problems.
Thanks for the help
swamprat1
 
Take it for what it's worth... (long way away from an expert)

I take the desired bullet and load it into a newly FL sized cartridge (which I do every loading as I have my dies setup to my chamber) one caliber in depth. On my .223, that seems to be the perfect depth for what I shoot. I then take a measurement for the ogive (as this is where I want to base my throating) and then have the throat reemed for that length. Now I can vary the seating a bit to touch the lands, have a slight jump, or possibly jammed just a bit (which - so far I do not do). I do not actually throat my barrels... I let my smith do that. I always give him a smaple bullet and the dummy loaded cartridge to use.

Recent example was .223 chambered CBI barrel with 1:8 twist shooting 75gr AMax (and I can shoot the 80gr SMK as well with a slight adjustment). the COAL was 2.467 and the ogive length was 1.941. Bullet length was 1.106 measured and 0.579 to the ogive (and the BT base was .175), calc. bearing length = 0.707. So with a 1.760 cart. length, that would make the freebore ~ 1.941 - 1.760 = 0.186 (again... approx as I do not have exact measurements)

Maybe you could modify that if you knew the measurement on the VLD yoou wnat to shoot?
 

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
166,996
Messages
2,226,577
Members
80,095
Latest member
Raqhmanov
Back
Top