I have some .308 brass (fired 2x) that the bullet can be hand seated/pushed/started into the neck. I do not turn necks. I have had this problem before with some Hornady brass. I measured the neck thickness as best I could with my dial caliper gauge. The problem brass had neck measurements .002-.003 thinner than the good brass, (IN Dia .308 compaired to the good brass .305). I couldnt find anything else wrong. So I chalked it up to some bad brass. Now I have the same problem with some Winchester nickel plated brass. None of the dies are set up any different than before. I even resized a few times hoping to tighten things up, but no luck. Has anybody had this problem before? I am using RCBS .308Win full length dies. If the outside dia is sized properly, but the inside dia is bigger (thinner necks), is this just bad brass? any help would be greatly appreciated!
Very loose neck tension???
- Thread starter whiplash
- Start date
- Oct 30, 2004
- 24,296
- 3,044
Grind down your expander ball or call rcbs.....
Try measuring the expander ball. it should run ~0.003 under bullet diameter. If it is larger you might try polishing it down or contact RCBS and see if they will do it for you.
You might also remove the expander and size a case you consider thin and see if the bullet is still loose fitting. If the bullet is tight when the case is unexpanded I`d consider the ball the cause and double check it.
The case measurment you want to find is the thickness of the wall, not the diameter of the mouth ID. Thick brass if similar to 7-08 and 260 rem brass will run ~ 0.013"-0.015" maybe more. Brass with a wall thickness of 0.011" and under is where I (I, personally) figure it as thin.
You might also remove the expander and size a case you consider thin and see if the bullet is still loose fitting. If the bullet is tight when the case is unexpanded I`d consider the ball the cause and double check it.
The case measurment you want to find is the thickness of the wall, not the diameter of the mouth ID. Thick brass if similar to 7-08 and 260 rem brass will run ~ 0.013"-0.015" maybe more. Brass with a wall thickness of 0.011" and under is where I (I, personally) figure it as thin.
- Nov 4, 2004
- 25,207
- 8,512
I agree with Pop, call RCBS and explain the problem to them. My guess is that they will send you a new expander ball.
JD338
JD338
- Thread starter
- #5
well you guys have some good input, as it got me thinking, and jogged my memory. I THINK the brass i have problems with was sized BEFORE I polished my expander ball. I was dealing with concentricity, and read about taking emery cloth and LIGHTLY polishing the expander ball a few months ago. That helped on my recent sizing. I measured my expander ball tonight (after emery cloth) and it was .305 (.003 under .308). I compaired that to my other expander balls from 30-06, .300Win Mag, and 30-30, and they measured .306. So I figured I removed no more than .001 from my .308 expander ball. The problem brass neck thickness measured .010-.011, as compaired to my good brass, as Ol Joe mentioned .013-.015. I still have 14rds left of that batch, so well see how that resizes with the polished expander ball. If I remember right, when I resized prior to polishing the expander ball, it was pretty rough as the ball passed back through the neck. Thats one of the reasons I ended up polishing the ball, along with trying to get things concentric. Now I just need a day off to go shoot.......thanks everyone for clearing some things up, and rattling my brain. I really need to start a journal, to write things down, like any modifications that were done etc.
rick smith
Handloader
- Apr 6, 2005
- 1,249
- 0
Another good reason to use bushing dies.Rick.
