how deep is seating too deep?

[Carphunter]

parallel to my other post, I'm beginning to wonder how deep is too deep when seating a bullet.

In constructing my 6.5x55's for my Encore, I'm trying some Sierra Pro Hunter 160 gr.  (so you know, I bought these bullets to try and cover the long space to the throat in my Swedish Mauser).

Anyway, on my mock bullet, I've ended up with an OAL of 2.964" on this sample. The case length is 2.159.  Case length from head to start of neck  is 1.85. The bullet length is 1.260.  So, when assembled,  .805" of the bullet is exposed, meaning .455 is inside the case:  .145" of the bullet extends past the start of the neck.

How deep inside the case can a bullet be, and still be safe?  

If this combo isn't good, I won't use it.... these bullets just seemed to work well for getting the measurements to my rifling.  I'll switch to gamekings if need be to make working loads.

[Iowegan]

Carphunter, I would go with 3.035" C.O.L . That is the recommended length for loading a 160gr bullet.  Seating the bullet too deep can be very dangerous. The internal space in the loaded case determines chamber pressure. The deeper the bullet, the higher the pressure.

[Questor]

I always use the specs from the reloading manual for seating depth, except to seat the bullet less deep so that the bullet is closer to the rifling. Seating it deeper than spec will generally increase pressures.  In some handgun calibers even a 10th of an inch can nearly double the pressure. Your caliber will be more forgiving than that, but it's still a concept to keep in mind.

[JBMauser]

My question is what is your planned load, are you shooting a Max load?  will a deep seated bullet compress your load?  I would not look to Sammi length for your single shot since you have no magazine to deal with.  I would compute my OAL from your specific chamber and apply a modest clearance to the rifling. What percentage of the case volume does your load occupy? These I think are more important factors for consideration.  a bullet which extends into a bottle neck cartridge is not a problem in and of itself.  RE: Swede 160gr. data -the Lee manual warns to maintain minimum OAL or longer with  Max (nerver exceed) loads.  That is saying you can have a good bit of the bullet in the shell if you stay in the midrange of pressure.  JB

[Steve P]

You did not mention your powder load.  I have shot lots of 6.5x55 ammo in model 38 and 96 swedes.  Most are throated long, and as such, you seat your bullet out, as you described.

If you need to seat the bullet a little deeper for your Encore.  Do it.  If you practice proper loading techniques, you will NOT raise pressures beyond what is safe in your Encore.   Lower the powder charge about 3 grains, seat the bullet a little deeper as you described, and safely work up.  Watch for pressure signs on the brass.  ALSO, If you have any problems opening the action or extracting the brass you are getting too much pressure.  

I have lots of wildcats built on the original Contender frame.  Some have such short throats that you have to seat the bullets into the case.  Just lower the powder charge and safely work up to your load.

Good luck.  You should end up with a tack driver and good deer gun.



Steve  

[Carphunter]

I've since discovered I have to get my bullets even deeper than when I first posted this thread.

I made my first round of bullets, and took them to the ran ge.  I figured out pretty quick that i had it mucked up....

So, remeasured thoroughly and made new loads.

Nothing spectacular with the 140 gn gamekings and H4350.

I'm going to look to see which loads gave me best pattern, and then try seating another .005 deeper to see if it helps.

After that, I'm moving to some lighter bullets to see if it helps.