6.8 rem spc

I can get cci primers.what # should fit?,Im wanting the smaller primer size.Why o why did they have two diferent sizes???.Thank you pan.:-?

several types of brass take two different primer sizes.
the 45 acp,40 s&w,7.62x39,454 casull, and many of the bench rest calibers.
some do it for a lead free type of primer, and some do it for ignition characteristics.
and others do it to help with pressure issues to keep the primer from backing out of the case.
if you have the small primer pockets then the regular #400 will work just fine. the 450 is their magnum number.
and their standard rifle primer will suffice if you have the large pockets.
if you are not sure which you have look at a scrap 223 round it is small rifle.

Thank you Run.I have both.Someone told me that the standard small rifle primers will not fit properly.I have a bunch of #400s.The more i shoot the 6.8 the more i like it.Kills without ruining a lot of meat if i use the 130grn. grand slam.pan.

#400's will work just fine, but I use #41, which is more of a mil-spec primer..

If you use Hornady brass or Winchester they both use SR primers. I use CCI-41 mil type primers in my AR. Remington uses large rifle primers so I would use CCI-34 on those.