Is there a prescribed method of fixing cases with neck run out of .004" or more? I have some .270 win cases that have been fired and when they were re-sized the neck run out was .004" or more.
Rather than try to explain the process in a small space, which you deserve better than, I will refer you to the articles which were in Outdoor Wife about two years ago. The articles were written by Jim Carmichel, May and June/July, of 2003. They are well worth the time to acquire if you are ready to double the time and effort you are currently putting into handloading. On the pages that I chopped out it gives this web address; www.outdoorlife.com/shooting
Rumshooter,
Can you remember the name of the article? Outdoor Life has very limited search and I can't find anything that looks like reloading article by Jim Carmichel.
Couple of things you need to find out, what is causing the runout and is it a problem with the grouping of that particular rifle. There is a device advertised in Precision Shooting that will move the bullet/case into alingment, can't think of the name of it right now.
Have you loaded any of those cases and tried them in your rifle?Rick.
Rick,
I had sized 100 new brass ( winchester ) and after firing 30 or so on load development and cleaning and re-sizing them I happened to check neck runout, mostly because of problem with another gun, happened to put some brass on RCBS Casemaster and checked them, couldn't believe they had .004" run out, so checked some of the un-fired but sized brass and noticed about the same amount of run out with them. Then checked fired but not sized case and it showed no run out. So took decapping / expander out of size die and sized couple of cases, they too had .004" runout. Did this to see if it was expander causing the problem. I"m going back and check all the unfired cases again and sort them as to neck run out although most appear to have close to .004" and do the same with the fired / re-sized cases and see if I can narrow it down more as to where its happening. I ran all the new brass through my sizer die and do not have any unsized for that lot to start over with and try to see where the problem lies.
Rick,
Also I'm using RCBS dies for this gun, loading for a buddy and he bought the dies and stuff for it. It seems like the collet die might be a better option when loading for hunting ammo. I use Redding bushing type neck dies on most of my own stuff. I also have several sets of RCBS dies and after finding this problem checked some sized brass from them all seemed to be OK, depending on if necks were turned or not showed acceptable neck run out. Everything I've read about neck run out seems to say less then .002" is OK but anything over is not good, although some say it does not make that much difference in group size for hunting rifles. Currently the best load for this .270 has been 140 AccuBond w/ H1000 got first load group of . 470" but velosity was not as high as I would like getting high 2700 fps with it. So maybe I'm beating a dead horse and should not have measured the neck run out in first place but now that I have its bugging me and for furture I'd like to know how to fix it.
You need to find what is causing the run out. Fired out of the rifle is good then it is either the die , shell holder or the ram is not concentric with the dies. If your other dies work well with this press and shellholder, it must be coming from the die, since you have eliminated the expander from the equation, I would work with the die and lock ring. I would take a case without any run out and use it to set the die and lock ring.Rick.
To add to this fine thread, get this book titled Precision Shooting Reloading Guide. If I remember correctly it had a section on fixing runout. As far as if it makes a difference, well it depends. If you have a match chamber then yes it probably will. But I have personally made some reloads with terrible runout and they shot fine ( 1/2"). So go figure.
Thanks guys for the info, I guess I'm going to figure that 1/2" groups @ 2700 fps in 22" barrel is going to have to do it for him. Animals won't know the difference between 2700 and 2900. Last time I loaded this upped the powder charge a little and was getting 2800 fps and still under 3/4" groups so. I'm going to follow up on adjusting the dies to case with zero runout see if that helps.