Full Case And Compressed Loads

[308win]

Is it generally preferable to use a powder that completely fills the case if possible for best consistency/accuracy. Also, when loading a compressed load what is the acceptable amount of compression - a few (how many?) thousands, equal to cal of bullet(?) or what?

 

[Big_R]

Speaking in general bottle neck rifle terms, it can be better to fill a case. Some people swear by it. Myself, I go with whatever powder charge gives me consistent velocities in the range I'm looking for. I'm also one of those guys who believe a 30-06 will never be a 300 win mag. The advantage of filling a case is more consistent ignition, ie. the powder can't shift away from the primer, hence better accuracy through more consistent velocities.

As for compressed loads, the same is true about powder shifting, although with compressing the charge, one is trying to get more powder, or powder of a different burn rate to attain higher velocities.

Overall, I've found accuracy is most effected by cartridge length (bullet seating) and proper firearms construction.

Ryan

 

[Delmar]

I personally subscribe to the theory of a full or very nearly full case for consistency. I tried compressed charges and did not see much of a difference in accuracy, but a word to the wise should you try compressed charge loading: Make sure the case has an excellent grip on the bullet as compressed loads (no more than 10%) tend to push the bullet out of the case.

 

[dakotasin]

agree w/ delmar.

i like the powder to be very lightly compressed, meaning the base of the bullet pushes on the powder charge very lightly - assuming i am working w/ powders that can do this and provide accuracy.

 

[caz223]

From what I've seen, lightly compressed loads with some powders are fine.
Others, however seem to gain nothing from it, and velocity stays the same, until you get one seated a little deep, then pressure is way to high.
I try to fill the case until the powder level is almost touching the bottom of the seated bullet.
Powder selection is important, and obviously this can't be done with all powders,or all calibers.