Is there a need to check short cases for runout?

[Goofycat]

I anticipate the delivery of .221 Fireball brass,small rifle cases) in a few days. It will ultimately be sized down to .20 VarTarg brass. Since this is a relatively short case, how important is it to check for case runout, say, as compared to the need for checking runout on much longer cases? The completed ammunition will be used in a Cooper rifle. I have no experience in runout in short cases, since I have not owned a rifle with cases shorter than .222, and don't want to have to purchase a runout gauge if the consensus is that cases as short as the .221 Fireball are fairly concentric to begin with.

 

[ballistic64]

All cases are as straight as thier going to be after firing them once.Its usually a step in the reloading procedure that will cause runout issues,the expanders in conventional dies are notorious for this.

 

[Goofycat]

Which leads to another question, this time about expander buttons. Froggy,6mmBR article) says that he never uses expander buttons, but he is referring to cases that have been fireformed. In his video "High Power Rifle Reloading," G. David Tubb says that he hones the button in his dies so that the button will only minimally touch the neck interiors,I don't know if he is referring to new or used brass). If the expander button is to be ignored, why and when is it to be used? Seems to me that once the brass has been fire formed, the necks have expanded to maximum, then slightly closed again when the case has been run through the die. Froggy says that the expander will just "tweek the neck or throw it out of alignment." So,,1) when is the button to be used, and,2) if it is used, how much honing is required? I am really confused on this point.

 

[ballistic64]

A conventional die will size the neck down much farther than it really needs to be,hence the requirement of the expander.
I use the bushing style neck die which doesnt require the neck to be opened back up by an expander.With the bushings you can also control the amount of tension holding the bullet,whereas with the conventional die you have little control over it.Ive heard of polishing the expander and trying to center the expander,but figured the best cure was the elimination of it with the bushing style dies and if need be to bump the shoulder when required,if chambering a neck sized case becomes difficult).

 

[steveyrock]

My BR has a .264 neck and I ordered a full lenght die from Foster with a .259 neck which is .005 under the chamber neck and I removed the expander ball to keep from over working that area.

as mentioned above,the standard die for a standard chamber will size the neck way more than is needed so the expander is needed to bring things back in line for bullet seating.

 

[Goofycat]

Considering I know zilch about bushings, are you saying that the bushing-type die allows the case to be sized in smaller increments than an ordinary die/expander combination would allow? And, if so, the exterior diameter of the neck is determined only by the size of the bushing used? And that the case ends up with no possible deformation from the expander,because there is no expander) when the case is lowered from the die? Sounds too good to be true. Do I have this right?

 

[Goofycat]

Here is the story as it stands today: I have on order a .20 VarTarg from Cooper Arms. Should arrive in a couple of months. I just received 500 .221 Fireball brass cases, which I will sort for weight, then square up the primer pockets and deburr the flash holes. That is about all I can do at this point. Then, the next step is to neck down the .221s to .20,with a Redding die in .20 VarTarg), trim and chamfer. The next question is: which die set to order,just the bullet seating die and the .20 VarTarg full length die....as far as I know) from Redding. I want a competition seater, and again, as far as I know at this point, a .20 VarTarg bushing-type die in full-length. I will have to have a .20 VarTarg dummy case made for the Stoney gauge to help determine cartridge length measured at the ogive,at .020" off lands, for starters), put together some loads and see what happens at the range.

For reasonably good accuracy,in other words, to try to check for case/bullet runout), which gauge,s) should I plan on ordering. Neco? Sinclair? And, is it important to even measure case and/or bullet runout prior to fire forming?

Mind you, I have never used a bushing die, being satisfied with plain-Jane dies with expander buttons in the past. I have not reloaded for almost six years and am trying to not only get up to speed again as to the reloading steps,as I remember them), but to throw in the added challenge of shrinking the cases from .22 to .20.....something I am not familiar with. I know this stuff is routine for you guys, but at this stage, I am in uncharted waters.

 

[ballistic64]

Gunamonth is right about the fact that if there is a difference in neck wall thickness,when sizing a case,the difference will remain after sizing.Turning the neck is the only way to eliminate this cause of runout.
I dont have any experience with the .20s,but with my .30 cal. this is my procedure.
Full size new cases with the expander removed.Trim the new cases to the shortest length case in the lot Im working with.Run the expander,neck turning expander,not die expander.I use the K&M turner,but many others are available) into the case necks to obtain proper size for the neck turner mandrel.Turn cases to completely true neck wall thickness to .014".In this case of the 30 cal. Im working with,removing a little over .001" completely trues the wall thickness to .014"
I then run the cases into the bushed neck die,Redding comp neck die) with a .334" bushing,which is .002" smaller than my loaded rounds.
Until I have fired the cases once,I wont even bother checking runout as its usually impossible to reduce runout to .002" or less with a new case,usually .004-.005 is the norm with new cases even if they were neck turned.In my experience anyway).
After they are fired,I clean them,run them in the comp neck die and load,I dont usually need to bump the shoulders for 2-3 firings).Ive generally found my runout to be under .001".So much so that I usually only check one cartridge for every 20 I load.
With your Cooper Vartag,Im assuming you may be high volume dog shooting and such,so I dont know how much time your willing to put into your reloading.All I can tell you is that it cant hurt your accuracy.
The .30 cal Im loading for was just finished for me and is more of a big game /target gun,but I did have some fun during deer season mowing praire dogs in half with some Berger 185 VLDs.
If I get my camera back from my friend in the near future Ill try and post some pics of the steps I do for you.Good shooting with your Cooper.

 

[Goofycat]

Thanks, Ballistic 64. Looks like I full-size the case to proper specs, fire them,and hopefully get some reasonable accuracy...whatever that is), THEN check for runout and neck wall thickness, etc. Either way, I can plan on having to buy the instruments to check for NWT and runout. If the neck wall trimming is required and I fail to do it, I will never know the potential of this nice little round. Lot of work,I have 500 pieces of brass in front of me. One of the reasons I don't like to miss shots.

Any advice as to which all-in-one gauge I should purchase to check for runout and neck wall thickness? I want to buy the one that is easy to use. I do not want to buy one that is a pain to use, ending up with my wanting to sell it, then have to buy the one I should have bought all along. I have been looking at the Neco, but have not bought anything yet.

 

[ballistic64]

The Neco is a good one and the price reflects it.I use the Holland which only measures neck/bullet runout,which is all I really want.Sinclairs is also a good one for this.

 

[ballistic64]

Goofycat, on the other hand,you can always load some rounds up without all the prep and see how it shoots,then do some prep and see if the extra work makes a difference for you.

 

[Goofycat]

Yeah, this is what I plan to do. Seems, though, that if there is a wall-thickness/runout problem with a .20 caliber neck, it will be magnified. I.e., .001" off in a .20 will be a greater percentage of error than .001" in a 30 caliber. It is interesting that the more I think about this stuff, the more questions pop up. Oh well, when I wake up at 3:00 AM, this is just another topic I can think about to get me back to sleep.