A while back (last summer) I loaded up some 55 grain ballistic tips in my .243 Winchester. I loaded them with varying charges of RL15 and seated them to an overall cartridge length of 2.705". As I shot them, none of them grouped terribly and as I climbed up the charge weights the groups seemed to consistently have a nice "round" shape and the groups got consistently tighter. The last group at 45.5 grains of RL15 threw the tightest group that rifle has ever thrown. It is just a stock Ruger M77 with tang safety so don't misinterpret me by thinking it threw 3 through the same hole [img]/ubbthreads/images/graemlins/tongue.gif[/img]
However, it was a solid .75" group. Anyway, I got to dinking around making up some more of those loads and decided that I wasn't seating them deep enough. So, I moved them down to a c.o.l. of 2.600". Group size tripled. [img]/ubbthreads/images/graemlins/frown.gif[/img]
I just got done loading up some at the original speciification but my concern/question is this:
With the bullet seated to achieve the c.o.l. there just isn't much of the bullet sitting in the case. I did some measurements last night and I have about .140 of the bullet in the case neck. Part of that length is the boattail. Is this enough to securely hold the bullet in place, and are there any other concerns I should be looking out for that I haven't thought about?