Originally Posted by Lefty7mmstw
Stop for a second here guys.....
The only difference between the 8 rem and 7 stw is neck diameter. NO FIRE FORMING IS NECESSARY....
Neck, square your brass in a trimmer, load and shoot. The first firing will be similar to having new 7stw brass and the head space will grow to where your rifle's chamber is. Have fun.
Another note; you don't need a third of a case of pistol powder to cream of wheat fire form. A five to 10 grain dump will do and you should try to run it as low as possible while still getting form. I personally dislike this way as it'll soot your pipe up good.
You are right about the chambers being the same except for the neck, but Each chamber is
slightly different and it is recomended that to obtain maximum accuracy you should fire a
case at least once in the chamber before loading for accuracy.
When a squibb load is used the case is not forced into the chamber hard enough to be consistant
from one case to another. This is the reason I use medium loads to fire form brass. (Fire
forming does not have to be only when blowing out shoulders or case body's) It is actually every
time you fire a round for the first time in a particular chamber. After that most size only enough
chamber. This keeps the case more consistant and extends brass life.
In fact I like to fire form new brass, then size it to just barely chamber, trim all the cases to the
same overall length and then weight sort to be the most consistant.
J E CUSTOM