I finished shooting a batch of .458 Lott loads just before Christmas and have been pondering a difficulty that arose. Perhaps some light can be shed.

The issue at hand was bullet runout, in the extreme. Realize that I'm shooting the Lott, with irons, standing, so benchrest accuracy isn't the goal here. I wouldn't give bullet runout a second thought with this rifle except for the fact that one round was so bad that it wouldn't chamber.

I'm shooting a Ruger No. 1 so I can get an excellent feel for how each round chambers. Out of 20 total rounds, I would guess that 6 chambered "very firmly". I really had to bear down with my thumb to get 'em to go. And, as I said above, one round was so bad that it wouldn't chamber at all. All the difficulties were caused by very noticeable bullet runout, approaching 0.050" (estimated) in the un-chamberable case. It was obvious where the chamber wall was contacting each "tight" round.

I'm shooting Hornady brass loaded with Hornady dies. Any and all opinions are greatly appreciated.

first you need to determine what caused so much runout. double check the die set up
Check a new unfired case at the sholder and at the neck before you do any thing to it. roll it across asmoth surface and check for wobble
Second check the case in the rifle and see if it chambers ok,
Next load a round and check after each step FL or neck sizing,
Seat a bullet check runout.
Fire the load and go through the process above.
you should find the problem by then.
dave

Mic the bullets independantly. They may be over or under sized. This is typical with mass produced "squeezed" bullets. A sheeet bullet makes for a sheeet loaded case dimensionally which makes for sheeety feeding!!

I had runout problems with several rifles. The problem was greatly reduced when I switched from spray case lube to Imperial Sizing Die lube. It's a cheap thing to try, no risk.

This may sound dumb...but your seating die isn't crimping at the last stage of bullet seating causing some deformation??

Kraky, the seating operation per se isn't putting any deformation in the mix, at least not that I can tell. I crimp in a separate operation. However, I don't put a true crimp on since I'm shooting a single shot, only enough to get rid of the bell mouth. There could be enough force involved to cause the problem though.

I wish I had a picture of the round that wouldn't chamber. It's really quite shocking. There isn't any crimping, crunching, bending, or denting involved. The bullet is just drastically non-concentric with the axis of the brass.

My sizing die produces a very noticeable bottleneck in the case. Seating a bullet pushes the brass back out. The bottleneck extends further down the case than the base of a seated bullet, so there is a small area (~0.5") where the case remains necked down in the loaded ammo. Really, before firing, this small area isn't in contact with the chamber wall.

In the problem rounds, it seems that the necked down portion of the case didn't expand equally around it's circumference to accept the bullet. In fact, for the round that wouldn't chamber, it looks as if the brass only stretched on one side to make room for the bullet.

I've made a crude diagram to make things a bit more clear. I'll post it if I can figure out how to do so.

Any chance that you are using a .45 pistol die set?

Nope, using gen-u-ine Hornady .458 Lott dies. I have mixed feeling about Hornady dies, but that's another topic.

Here's a diagram of what I attempted to describe above. The "necking" of the case is exaggerated.

is there any chance that the expander ball
is too close to the neck sizing portion of the die??? if so screw it out a little further so there is more decaping pin hanging out..

It's a 3-piece die set, so no expander ball to speak of...one die to size it down, one die to give a little bell mouth to perch the bullet on, and one to seat the bullet

I'll be loading another batch soon, and you can bet I'll be paying extra attention to find the root of the problem. Gonna measure the case wall thickness at various points around its circumference for starters. Stay tuned...

quote:

Originally posted by 458_wanderer:
Gonna measure the case wall thickness at various points around its circumference for starters. Stay tuned...

Measure the neck O.D. of virgin brass, fired brass, and sized brass. For all the world, what you are describing sounds (and looks) like brass that is being sized with a .452 die. Is it being full-length sized? I assume that you are using the seating die in the separate crimping operation.

I don't recall if Hornady marks their dies with the part number, but your sizing die should be 044457, if that's any help. All of their other 45 cal. sizing dies are 0445xx.

Hey 458, Great drawing of the problem.

I'd recommend you email Hornady and include a Link to this thread. Or at least send them a copy of your drawing.

They might ask you to return the Dies to them with a couple of Fired Cases so they can adjust them. Lots of excellent folks at Hornady who are always willing to help a Reloader.
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I've had Straight Wall Revolver Cases end up with a similar profile using Carbide Dies, but mine Seated straight enough that they were no problem to chamber.

The only Straight Wall rifle Cases I have at the moment are 444Mar. They also show a slight bit of "stretch" for the length of the Seated Bullet, but of course that is to be expected. None of mine appear to be Skewed or Canted, but if they are, they still feed and chamber fine.
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I believe this Link will take you to a simple way to straighten Run-Out by "Reloader" who posts here. Perhaps it can help you in the short term.

Best of luck to you.

458,

What bullet are you trying to load? I think that the Hornady seater works good for the RN style that Hornady makes, but may not work as well for a pointed bullet such as a Swift or TSX. In any case, contact Hornady, and they should be able to help you out.

Same problem?

[SEE BELOW]

https://forums.accuratereloading.com/eve/forums/a/tpc/f/2511043/m/472108597

Hell if I know what happened. I'm just pushing the buttons.

I Have had this problem on some smaller cartridges...

The cause was that the shell holder, had allowed the cartridge to slant forward slightly...

so what I have to do is let push the base of the case back with my thumb as I lower the ram handle until the case guides into the die...

I am using the proper shell holders, but the problem occurs the most often with the 223 and 22/250.... however I have had it happen on cartridges up to the 30/06 and my 444....

so far not a problem on my magnum cases, but I don't shoot those very much...

I shoot a lot of 22/250 and 223.. makes one wonder if shell holders can wear out? or have tolerance wear on them...

pushing the base of the case back with my thumb eliminates the problem tho...

I guide my cases into the neck sizer by rotating them. I then size in small steps, withdrawing the case and rotating it a little before pushing it in further. I do the same for bullet seating. I don't get any measurable runout this way. But if I don't do this, the cartridges won't chamber! In my hornet anyway.

Has there been any resolution?

A really dumb suggestion, but check to ensure your case base is going all the way into the shellholder. Take a pick or small nail and see if you can find anything that might be not allowing full entry into the shellholder.

No resolution yet. I hope to get busy loading this weekend.

never had one run out - always shot them, (OK so its way below zero here and windy and friday and my brain is frozen)