Crooked case necks

[jnmullin]

I am having some trouble with sizing a couple calibers. On both 30-30 and 303 British, the necks are coming out crooked after sizing. I have tried both full length and partial length sizing with both new and once fired cases. It doesn't matter which method or which cases I use. The runout seems to be random; some are bent awfully, and a very few are almost perfect. In 30-30 I have used Redding and Lee dies, with Redding and Lee shell holders. In 303, I have only Lee dies. My press is a Frankford Arsenal from Midway. In the calibers that I have the collet neck sizer for, I have no visible runout at all. The lube I am using is Imperial Sizing Die Wax, and I am actually following the directions for once.

When I got the set of Redding 30-30 dies, the decapping rod was visibly off-center, so I sent it back to them. The replaced the rod and the die was within specs. It was bending the necks very badly before I sent it back, anfd isn't as bad now, but it is still happening. I am following the directions for all sets of dies. The new cases for both calibers are Winchester; the fired cases are mixed brands. What I find really strange is that all of the new Remington 8x57 cases that I have run through my Hornady die set have almost no runout at all, as measured by my super-scientific method of watching them roll across a flat surface.

Any ideas that y'all can give me will be greatly appreciated.

Thanks in advance,
John Mullins

 

[jnmullin]

BTT

 

[swifter]

Polish the expander ball: Chuck in a drill, spin while pinching emery cloth in increasingly finer grades around it, finish with crocus cloth to mirror polish.

Lube case neck interior.

Install a small O-ring between the die top and the decap stem nut to allow some flex for self-centering.

This should help.

Tom

 

[zeke]

jn- Couple things ya might try.

1-don't lock down the sizing die, put fired case in shell holder and pull lever down till case is fully inside die. Now lock down the rezing die.

2-don't lock down the neck expander, or lock it down when the case is being lowered after it has been rezied. Wait untill the expanding plug gets self centered in the neck.

3-have tried these methods after just squaring up the reziing die by using flat washers on top of shell holder and raising up till the resizing die is under pressure, then tightening the lock collar.

 

[Clark]

Once an expander ball has been pulled through a neck, shooting and reszing may not straighten it out.

Take some brass that has been once fired, but never seen an expander ball.
Take the expander ball stem out of the sizing die.
Resize the ammo, but don't set the shoulder back.
Prime and load the ammo.
Now when the concentricity guage measurements are done, results will be much better.

If the bullets will not start to be seated becase the necks are too small, either:
1) lapp out sizer die neck
2) get a bushing die
3) resize as described above, but then put the expader ball stem back in the die and in a separate step, after the cases are sized, introduce the expander ball just enough to bell the mouth of the case enough to start the bullet. Pushing the exander ball is much less likeley to bend necks than pulling an expander ball.


I have never seen any bullets yet that will not seat without the expander ball, but you may find some.

How to fix brass that has had an expander ball pulled through: get a mandrel or expander ball from the next size up bullet, ie .323" for a .308 cartridge. Expand the neck with pushing. Then resize the brass to 308 with no expander ball stem. The brass will then look good on the concentricity gage.

 

[jnmullin]

I have tried most of what y'all suggested. If I resize with no decap rod, the cases come out nice and straight. If I use the decap rod, whether locked down while centered or left loose, the necks still come out crooked. The cases are lubed with Imperial Sizing wax, with a touch to the mouth of each case. If I seat a bullet without using the expander, it noticably bulges the neck and become way off-center. I am using Lee locking rings with the O-ring on my Redding 30-30 dies.

After locking down the Lee 30-30 die with a case inside, the 3 once fired cases I tried come out almost perfect. I really wish I knew what was going on with these stupid things.

Thanks,
John

 

[Clark]

It has been my experience that the expander ball will make the concentricity ~.004" or worse referenced from just rear of the shoulder and just forward of the extractor rim, and measured at the ogive of the bullet.

Seating with RCBS dies can add ~ .001" of excentricity that is removed with Forster type [the patent has now expired and Redding also makes them and RCBS makes a few] seater dies.

Oddly, the best groups I ever got with my 30-30 was with cheap .308 Win dies and seated the cast bullet so long they had to be loaded single shot. Buying expensive Forster 30-30 dies and seating so the ammo would feed from the tube does not work for me.

 

[Dave P]

In the calibers that I have the collet neck sizer for, I have no visible runout at all. *****Collet dies are very good, if you don't need to re-size the case.

cases that I have run through my Hornady die set have almost no runout at all, ****** Hornady dies are are very good these days.
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