Home Forums Reloading Big Game Rifles ? on crooked cartridges.

I recently bought a 6.5 Grendel. I bought some Hornady brass for it and a set of Redding series "C" dies. If it helps I use a Forster Co-Ax press. After loading some bullets I checked them on my concentricity gauge. With new brass less than 10 of the 50 loaded were further than .003 out. After shooting them I resized all and loaded 10 more with a different primer. All ten were well out of alinement. I then checked the unloaded case necks and found them to be well out too. I happened to be reading Mule Deer's book ... Gack II and remembered he said to take the depriming pin out to have straighter cases. I re-ran the cases through the die and they came out .001. Then I loaded the bullets. Almost all were again very crooked. I straighten them on my True Tool and they shoot great. My question is why would they go crooked after making sure the cases were straight and then loading the bullets? The die didn't seat them crooked before and no adjustment was made on it.

Might try posting this on the Gun Writer forum and maybe Mule Deer may have an answer.

Thought about that, but figured it should go in the reloading section. He gets here occasionally. If I don't get some action on it soon I'll go there.

Any chance your seating stem is out of alignment or doesn't fit your bullets?

Id also be looking at the seater as the culprit.

After you sized the brass without the expander ball did you take any steps to expand the necks to a proper size for the correct interference fit when seating bullets?

I've dealt with gremlins of that nature since forever, and it never seems to be the same solution twice. Even with premium top quality dies there's room for error to pop up. (I've long suspected that the average reloading press's rams are seldom in perfect alignment with the die holes, not to mention slop in male and female die threads and slop in ram fit.) Nowadays when I want the ultimate in perfectly straight ammo right out of the chute, in selected calibers, I resorted to using straight line L.E.Wilson dies and an arbor press. Oh my god slow, but oh my god straight ammo, as confirmed with my Sinclair concentricity gauge. Besides, what's time to a pig?

Wouldn't that cause the necks to go back crooked? Also, I used the same style and brand of bullets. 100g NBT. They did not seat hard.

The seater wasn't a problem when originally loaded. Also, it wasn't adjusted after the first loading when cartridges were much more straight.

That depends on tools, technique and the brass itself. I rarely ever use the expander ball in FL dies in the conventional matter. If I FL size I push the neck over an expander mandrel in a subsequent operation. When the brass has good necks I rarely see as much as .003" runout in the assembled rounds.

What mathman's talking about is pushing the expander ball through the neck (starting from the outside) in a second step, rather than pulling it through (from the inside) during the first sizing step.

Either way, you do need to expand the necks if using a standard FL die, otherwise the neck inside diameter is usually way too small and that can cause both runout and neck tension issues.

This kind of thing is also why a lot of guys chasing accuracy and low runout like to neck turn their cases; uneven neck thickness can cause runout during both sizing and seating. Adjusting neck wall thickness can also be used to adjust neck tension on the bullet.

Would double seating help in this case?

I recently purchased a Hornady concentricity gage and found that my ammo assembled using RCBS and/or Redding NS/FL dies and Hornady New Dimension seaters with the sliding sleeve were consistantly within .001" - .003" concentric. I no longer check concentricity and with proven loads get MOA accuracy.

Now you guys got me really confused. How does one pull the expander ball through the neck from the inside without first pushing it through from the outside? I hope I am not being too dense.

You size with the expander removed. Then you put it back in the die but screw it down so it expands the neck before the case contacts any other part of the die. Mule Deer wrote about this in (I think) Gun Gack 1. The idea is that the bottom of the case is flat against the shell holder as you raise the ram and it makes more concentric sizing than pulling the expander out when only part of the rim is contacting the shell holder.

If the expander ball is in your sizing die when you first size the case, it doesn't (shouldn't!) have to expand the neck on the way in, only on the way out after the neck is squeezed down in the die.

If you run the case into the die without an expander ball, then push it through in a second step, the neck is already sized small so the expander ball has to expand the neck as it's pushed in.

Ok. Thanks.

If you want to decap during the sizing process, screw an expander from a smaller caliber into your sizing die. For example use a 270 expander stem in your 30-06 die so it pushes out the primers without contacting the case. Saves buying a separate deprime die if you don't want to mess with that.

Never thought of that. I may have to try it.

Variable neck wall thickness most heavily expresses itself after ones slugs have been seated. Turn/ream one's necks and the issue may vanish.