|
Two other things I have had in the past that drove me nutty just like this.
One was case neck tension. I loaded up some test loads, found my accuracy and everything was peachy. Loaded up a hundred rounds for the years worth of practice and hunting. Next time out that fall, groups weren't even within 2". Couldn't for the life of me get it down. Figured what they heck and pulled a round just to check the charge weight just in case. The bullets on some were nearly scraped shiney all the way around from the brass contracting on them where as some simply eased right out, and looked like they just came out of the box. Lesson learned for sure.
The other thing was while working up loads I was simply shooting 10 - 20 rounds, between a thorough cleaning. Similar situation, great load found, loaded up a quantity, and was happy. Couple of months later same load, same everything, groups in the 3" area. Cleaned the bore, and repeated, with same results. Got fed up and simple decided to work on trigger pull and such and after about 8 consecutive rounds the groups dropped to around an inch, then a bit smaller and stayed there. Cleaned the rifle up and back to 3" groups. Only thing I could remember was that when I did the initial work up, I also had two other rifles and possibly had switched over to allow this one to cool and not cleaned between rounds. Once fouled it shoots like a laser, but when clean all bets are off.
Similar to one of my revolvers, if you clean it up to spotless, you might as well simply walk out and shoot at least three full cylinders through it before putting it on paper if you want any reasonable accuracy. It just likes it dirty.
__________________
LAter,
Mike / TX
|