Is it normal when bullets seated at jam are only half way in the neck?
Registered User
Is it normal when bullets seated at jam are only half way in the neck?
Registered User
Yes. Or, at least it depends on the freebore in your chamber and thrilled being used.Originally Posted by nksmfamjp
Most 6PPC chambers used by competitive shooters have around a .050 freebore, some a tad longer.
When using typical 65 to 68 grn bullets made on .790 or .825 jackets, the ideal location for the base of the bullet when touching the lands is a little past half way into the neck.
Other things can affect this. If you are shooting a flat base bullet with a rather low number ogive, such as the original Fowler and Watsons at around 7, the base of the bullet will be around 2/3 the way into the neck in a .060 freebore chamber.
Starting around 15 years ago, boat tail bullets with double radius ogives became popular, and you naturally have to seat the bullet further out to reach the lands. Adding a boat tail made it where you would actually have the straight portion of the bullet shank only around 1/8 inch in the neck.
This all works fine. For a number of years now, I would guess that quite a few bullets being made for Short Range Benchrest bullet makers feature a double radius ogive and a boat tail. The original Paglia and Bruno Double 00 statrted this trend. The original Barts flat base Ultra also featured a rather high number ogive with a double radius ogive.
Last edited by jackie schmidt; 03-01-2021 at 07:59 AM.
Registered User
[QUOTEWHEN I PUT A STRAIGHT EDGE ON A BULLET I DONT SEE A DOUBLE OJIVE.=jackie schmidt;842483]Yes. Or, at least it depends on the freebore in your chamber and thrilled being used.
Most 6PPC chambers used by competitive shooters have around a .050 freebore, some a tad longer.
When using typical 65 to 68 grn bullets made on .790 or .825 jackets, the ideal location for the base of the bullet when touching the lands is a little past half way into the neck.
Other things can affect this. If you are shooting a flat base bullet with a rather low number ogive, such as the original Fowler and Watsons at around 7, the base of the bullet will be around 2/3 the way into the neck in a .060 freebore chamber.
Starting around 15 years ago, boat tail bullets with double radius ogives became popular, and you naturally have to seat the bullet further out to reach the lands. Adding a boat tail made it where you would actually have the straight portion of the bullet shank only around 1/8 inch in the neck.
This all works fine. For a number of years now, I would guess that quite a few bullets being made for Short Range Benchrest bullet makers feature a double radius ogive and a boat tail. The original Paglia and Bruno Double 00 statrted this trend. The original Barts flat base Ultra also featured a rather high number ogive with a double radius ogive.[/QUOTE]
Tim B.
Yes. That way you can jam in more powder.....
Registered User
Yes. Or, at the very least, it is dependent on the freebore of your chamber and the thrilled that you employ.
Posting Permissions
Reply With Quote