Freebore diameter

[Radar]

I have a 30 cal. that leaves scratchs on the bullet and seems to throw a shot or two in almost every 10 shot group. I have a barrel stub and it takes alot of hand pressure to push the bullet in it. So how tight is to tight? I'am thinking I should probably rechamber with a different reamer.

 

[Alex Wheeler]

I like .0002" over bullet shank diameter. What do your bullets measure over the shank? The pressure ring can be larger than the freebore diameter without negative effects.

 

[Radar]

I like .0002" over bullet shank diameter. What do your bullets measure over the shank? The pressure ring can be larger than the freebore diameter without negative effects.

I don't remember what they measured but I'll measure them in the morning. It's not just the pressure ring it's the entire bearing surface on four different bullets from Berger and Hornady. What I'am wondering is if anybody has seen tight freebores causing flyers.

 

[Alex Wheeler]

If your freebore is that tight, its definitely a problem. No better than not having enough neck clearance. Your best bet is to just order a throater from JGS and just run it in enough to clear up your freebore.