Curing bullet runout in your cartridges.

[jamesdmock]

After reading the Daily Bulletin, I thought of something that Mr. Ferris Pindell told me at the Super Shoot many years ago. While I am not taking away anything of what was stated in the aforementioned article, I would like to add Mr. Pindell's comments to the discussion. For those few who do not know who the late Mr. Pindell was, he is known as the Father of the PPC cartridge (along of course with Dr. Lou Palmissano).

Ferris told me that runout can be caused by several factors, but the most common cause can be traced to the sizing die. This statement is from a master tool and gage maker who has made many bullet dies in his career.

A great FL die is the best cure, but there are a few other tricks that can help solve the problem. If the FL die is a bushing type, then the bushing should be allowed to float slightly so that it can seek its own center. (also, let me add the bushing should be checked for concentricity) another thing that I do is not let my die touch the shell holder. This can be accomplished by grinding ~ .020" off the top of the shell holder. This will allow a small amount of centering of the brass and the die. I believe that it was Gary Ocock that gave me this tip, thanks Gary. These are some of the methods that I have used along with the use of good seating dies. If you would, please add your methods for obtaining straight ammo. Good shooting........ James
PS- Mr. Pindell was a good friend of L.E. (Sam) Wilson. They were both great shooters, inventors, and they both had a love for shooting pool.

 

[jepp2]

If you would, please add your methods for obtaining straight ammo.

Several years ago I read "Precision Shooting Reloading Guide" by Dave Brennan. I learned a lot of things I needed to check. Biggest factor was, no matter how well you lube the inside of the case necks, if your expander has to enlarge the neck 0.003-0.004", it is going to pull the neck off center.

I changed my practices, I hone my die necks, I set my expander high when I use one, and I float my die with an O-ring (controversial I know) * but covered today in the bulletin https://www.facebook.com/USAMU1956/posts/10153707187509734:0

With the changes I made, my die neck runout after FL resizing is ALWAYS less than 0.001" TIR.

 

[Tim Singleton]

I moved away from neck bushing sizing dies and away from inline Wilson seater to a custome sleeve type seater from Whidden
Cut my runout in half

 

[Shynloco]

Several years ago I read "Precision Shooting Reloading Guide" by Dave Brennan. I learned a lot of things I needed to check. Biggest factor was, no matter how well you lube the inside of the case necks, if your expander has to enlarge the neck 0.003-0.004", it is going to pull the neck off center.

I changed my practices, I hone my die necks, I set my expander high when I use one, and I float my die with an O-ring (controversial I know) * but covered today in the bulletin https://www.facebook.com/USAMU1956/posts/10153707187509734:0

With the changes I made, my die neck runout after FL resizing is ALWAYS less than 0.001" TIR.

+1. And I also use the "O" Ring method to float my die and shell holder. Started that a few years ago and improved my runout considerably, even when using Bushing neck dies which do cause runout increases. A custom FL die will cure that issue and took me from .002/.003 to .0005-.015. That's good enough for me.

Alex

 

[BoydAllen]

Concentricity gauges are IMO best used to diagnose equipment issues. One piece dies that do not require the use of an expander ball, which are closely matched to the chamber in their other dimensions (assuming you are serious and and are using cases with turned necks) give the best sized brass concentricity. The problem is that custom dies can be expensive and may require adjustment to get the fit that you want. The other approach is to start with a standard one piece die, and design a tight neck chamber reamer based on the dimensions of sized cases from that die. I have done this multiple times and it works very well.

If you are using a threaded sliding sleeve type of seater they can be tuned up to produce better results. Setting them up to lightly toggle on the shell holder can have a beneficial effect on BTO consistency.Trimming the bottom of the sliding sleeve a bit so the case pushes the sleeve up rather than the shell holder gives a better fit of the case in the sleeve. I have also seen the inside of the bottom of the sleeve shimmed to fit sized cases better using a strip of carefully applied tape.

For both sizing and seating letting the shell holder float a bit helps. To accomplish this you can remove the spring clip retainer from the top of the ram and replace it with an O ring. The clip actually holds the shell holder slightly off center. Another thing that can be done is to reduce the diameter of the lower flange and that of the smaller diameter between the top and bottom flanges, to make some clearance so that the shell holder and case can center on the die.

Using an O ring under the die lock ring helps, as does using a Lee lock ring with an O ring built in. When using the latter, be sure not to tighten the ring to the point where its outer edge contacts the top of the press. Doing this would negate the advantage of the O ring. Another thing worth trying is turning the case and seating in stages.

 

[chop house]

if your expander has to enlarge the neck 0.003-0.004", it is going to pull the neck off center.

i am an engineer, but not a materials guy. is brass stronger in compression than in tension? IF that is true, would there be a benefit from two separate operations... i.e. size without the expander, then reinstall and expand on (short stroke) upstroke? or does that all go out the window if the anneal is not perfectly uniform?

years back i started comptemplating this, then for my purposes found the collet die / wilson seater workable in re t.i.r... as the ff brass out of my chambers was already very straight.

 

[BoydAllen]

If you take the bushing out of your FL die, effectively turning it into a body die, and check the runout of cases you size with it as compared to fired, I think that you will be pleasantly surprised. All that you need to do to complete your process is to neck size with a collet die either before or after body sizing. For unturned brass this is probably the best of all possible sizing processes. When I did some testing with one caliber, years back, neck sizing first and then using the body die gave better results. I suggest that you do your own testing.

 

[centershot]

I use a Wilson die. How do you "float" the bushing? It just sits in there flush.

 

[T-shooter]

If there is a problem with the brass, no die will fix the runout. I had a box of new .308 Hornady brass. I always F/L resize them first, then expanded and neck turned and resized again to get the necks into specs. These showed .006-.010" runout on the turned necks. I fired a few and one side of the necks was perfectly clean, the other side had soot. I annealed the fired ones and re-turned the necks. The cutter didn't touch until about 1/8" from the shoulder, then only took off metal on one side. So I did the rest of the unfired cases, the same thing, metal removed on 1/2 the diameter of the necks about 1/8" from the shoulders. Afterwards the runout on the necks ran from .001" to .003" even for the unfired cases.

 

[jdh47]

Thanks James and Boyd. It makes sense and perhaps I should try that. I try to pay attention to other peoples successes in an attempt to get better results. Everything can be improved.

I have been using a Redding FL bushing sizing die with the bushing and the expander removed. Then I use a Lee collet die. Seating is done with a Wilson chamber type seating die. This works for me if the cases have little to no case neck variance and cases are checked before, during and after loading.

Expanders have not worked well for me and I went to the collet die because I get pretty good results. Some cases do not spring back the same as others due to differences in hardness I suppose.

Joe

 

[JRS]

If there is a problem with the brass, no die will fix the runout. I had a box of new .308 Hornady brass. I always F/L resize them first, then expanded and neck turned and resized again to get the necks into specs. These showed .006-.010" runout on the turned necks. I fired a few and one side of the necks was perfectly clean, the other side had soot. I annealed the fired ones and re-turned the necks. The cutter didn't touch until about 1/8" from the shoulder, then only took off metal on one side. So I did the rest of the unfired cases, the same thing, metal removed on 1/2 the diameter of the necks about 1/8" from the shoulders. Afterwards the runout on the necks ran from .001" to .003" even for the unfired cases.

Evidently, you have never used a WTC sizing die.

 

[mikecr]

Even with inline dies, floated bushings, floating fitted stems, and neck turning, etc., you will still introduce runout with sizing. This is because the root cause of runout is yielding of thickness variance.
If you culled out thickness variance, your runout over the long term would drop considerably.
If you stopped sizing all together, your runout would go to that produced by your best die(your chamber), which is very very low.

Where your plan includes use of a cartridge of relatively poor reloading design, sloppy chamber, and a bunch of FL sizing, then your plan is accepting of ever growing runout. If you're there and not accepting that result, then your plan was flawed.

 

[swadiver]

Lee collet die?

 

[jepp2]

Expanders have not worked well for me and I went to the collet die because I get pretty good results. Some cases do not spring back the same as others due to differences in hardness I suppose.

Since the Lee collet die can't undersize the case neck like a FL sizing die can, you do have to anneal more often. But I also have excellent neck runout using a Redding body die and a Lee collet die. It is just a 2 step process.

I use the Redding Competition bullet seating dies for most calibers I load. I have to admit, I was pretty disappointed in the runout I was getting during bullet seating. With case necks that had less than 0.001" runout, I was seeing 3-5 thousandths as measured near the ogive or closer to the tip. I gave seat partially, turn case, seat more, turn case and fully seat the bullet a try. For me it reduced bullet runout by at least 2/3, down to were most were 1-1.5 thousandths.

 

[swadiver]

I also use the Lee collet die in conjunction with a Redding body die with excellent results. Forrester or Whidden for the seating dies

 

[jepp2]

I also use the Lee collet die in conjunction with a Redding body die with excellent results

Just curious, which die do you use first? I normally use the body die first, then the collet die. Not sure it makes any difference on order, but I really haven't tried using the collet die first.

 

[swadiver]

I use the Lee for the necks first. I have tried it both ways but really didn't see a difference

 

[onelastshot]

Could someone explain what bullet runout is?

 

[gotcha]

Just curious, which die do you use first? I normally use the body die first, then the collet die. Not sure it makes any difference on order, but I really haven't tried using the collet die first.

Same for me, body die 1st. Results have produced very low R/O consistently on turned and unturned necks. So good that I've never considered reversing the process.................. Not saying you shouldn't be curious and give it a try.

 

[jepp2]

Could someone explain what bullet runout is?

The bullet isn't straight in the case neck. If you have much runout, you can see the bullet tip wobble when you roll the case on a flat surface. This means the bullet can enter the throat/lands with the tip not axially aligned with the bore.