Decreasing bullet runout during bullet seating

[B-P-UU]

I recently acquired the Sinclair concentricity gauge and am now determining what steps of my reloading process are contributing to bullet runout. I'm currently reloading for my .204 (Hornady brass and 39 gr SBK pills). Once fired brass give less than 1 thou runout. Brass resized using a Lee collet die also give less than or equal to 1 thou runout. When seating bullets using the Lee "dead length bullet seater" (the one that comes with the collet dies); I'm seeing anywhere from 1.5-5 thousands of runout in the loaded ammo with most averaging around 3 thou. Measurement is taken on the ogive close to the ballistic tip.
I have noticed brass with a more aggressive case mouth chamfer helps with runout so I have went back and re-chamfered the brass with a VLD style chamfer – even with this, I'm still seeing high and inconsistent runout. I'm not sure what bothers me more, the high runout values or the extreme spread (one round will be 2 thou runout and the next will be 5 thou).
Also noteworthy; I'm not using the lock nut w/ O-ring provided with the lee seating die. I've replaced it with a Hornady-style collar.
Suggestions appreciated; thanks.

 

[gilmillan1]

There is only so much perfection you can achieve without moving into advance reloading. In order to get more consistent cases, you will have to do complete benchrest cases, meaning you will have to start turning necks. In addition, you will have to sort all of your bullets, and if you want more consistency, weight them as well. You need to decide why you want such level of perfection. If you have a hunting rig, you probably dont need to get into such hassle. Its up to you.

 

[ultraedge]

The best method that I have found to get low runout is as follows: 1. size brass 2. neck turn 3. load and shoot in a good chamber 4.resize and reload with quality dies such as Forster or Whidden. 5. when seating the bullet, rotate the cartridge in the shellholder at least three times and seat in each position. Using this process , I rarely have loaded cartridges that exceed .001 runout. Cartridges that I normally load are .22-.250, .243, 7STW, .308, .300 RUM, and .338EDGE. Gary

 

[flashhole]

A Forster benchrest seat die will go a long way to minimize your runout. You don't need the micromerter adjust the Ultra comes with. The sliding-sleeve, tight-tolerance axial alignment of bullet to case design is superb. Your lee die will work well on blunt or flat nose bullets but not so good for points.

 

[CB11WYO]

I just got a Hornady Concentricity tool for Christmas and have actually been impressed with the readings I get on my reloads straight out of the seating die. I use plain ol' RCBS and Redding dies and usually see .001"-.003" runout in a box of 50, with only a handful being .003" out. Not exaggerating, seriously...

From pictures it doesn't look like the Sinclair concentricity tool lets you tweak the runout after measuring. The Hornady one is handy in that once you get a reading you can then crank the thumb-screw which presses laterally on the bullet until you have a satisfactory amount of runout. Getting to less than .001" runout with this method is usually pretty easy.

 

[steeltraps]

Here is what i do with all the custom guns i have built. Fisrt i buy a Harrells Precision blank, then i have my gunsmith use the same reamer he used on my rifle barrell to make my seating die. Then when i fire the rounds i send John Whidden 2 peices of fired brass and in 3 or so i have my fl or neck dies sent to me. I think the last set of bushing dies where around 200 dollars or so. Whiddens will make you what ever you want. You can just send John a print of your reamer or if its real popular he may allready have it on file .

 

[Mikecr]

I just got a Hornady Concentricity tool for Christmas and have actually been impressed with the readings I get on my reloads straight out of the seating die. I use plain ol' RCBS and Redding dies and usually see .001"-.003" runout in a box of 50, with only a handful being .003" out. Not exaggerating, seriously...

From pictures it doesn't look like the Sinclair concentricity tool lets you tweak the runout after measuring. The Hornady one is handy in that once you get a reading you can then crank the thumb-screw which presses laterally on the bullet until you have a satisfactory amount of runout. Getting to less than .001" runout with this method is usually pretty easy.

You're seeing less runout because the Hornady is greatly inferior to the Sinclair V-block for measuring runout, and neck bending does not actually reduce runout.

BPUU, that your fired runout as measured on necks did not increase with collet neck sizing means whatever thickness variance you have in the brass is still internal. It wasn't driven outward. Then you seat bullets into this internal runout, and see the result of it while measuring off bullet noses.
You need to expand necks to drive thickness variance outward. With this, seated necks will measure higher runout, but lower off bullets(because they will be seated straighter).
I recommend Sinclair's expander die system for this.

 

[CB11WYO]

...You're seeing less runout because the Hornady is greatly inferior to the Sinclair V-block for measuring runout, and neck bending does not actually reduce runout...

You have my attention, please expound ??

I think I understand that readings would be different between the two brands because of different methods of suspending the cartridge. A cartridge which had .005" runout on the Sinclair might appear to only have .002" runout on the Hornady and therefore might be deceiving. I could again influence that number by using a different/incorrect bullet spindle on the Hornady which would hide/reveal runout.

What did you mean by "neck bending"? I think that's where I'm behind.

Like I said, only been using one since christmas...

thanks

 

[Mikecr]

I refer to the Hornady style 'concentricity' gage as a 'neck bender' because that's what your adjustment is doing.
This does nothing good for actual runout, and the tool doesn't measure runout.

You don't have straight ammo(runout free) until measured so on a v-block runout gage.
The concentricity gages are popular because they read very little actual runout and most reloaders don't know the difference between runout and eccentricity.

Pick up a Sinclair, measure some ammo side by side with the Hornady, learn from this and sell off the Hornady.

 

[CB11WYO]

Thanks mike

guess I'll do some digging, rat's a racin' now...

runout and eccentricity... hmmm alrighty then. At least now I have a rabbit to chase on a slooooow saturday at work.

 

[flashhole]

The Forster tool is pretty good too.

 

[Trickymissfit]

Mike's right, and many just refuse to accept it. I use a Neco, plus a couple home brew gauges. They use nothing but standard wand type indicators, and these are well know to be the most accurate.

Now for a good seating die, I will say get the Forster and take that part out of the equation. Of course you could order one in 17 Remington, and run the chamber reamer thru the sleeve (easy and accurate). I have found that if a sized case has five tenths run out in it, it will end up at about one thousandth loaded or maybe a couple tenths more. So your sizing operation is where to start. Are your dies perfectly aligned to the shell holder, and also is your die strait with the moving axis. If not, your simply adding error. If the shell holder is .0003" out of square, that error will often come out to .001" when it triangulates out or even more. Machining error alone will often give you that .0003" without the shell holder in place. Try another shell holder from a different brand, and stone the area it seats on lightly to remove any bumps and burrs.
gary

 

[65WSM]

.204 Ruger is becoming my favorite cartridge because I can afford to shoot it.

I used the Wilson seating die. I have reamer/blank Wilson dies in 4 cartridges but am using the stock off the shelf Wilson in .204 Ruger. No need to change. It is simply perfect for seating the Hornady and Sierra plastic tipped bullets I favor. I use separate stems and caps for each bullet. I have 3 stem and caps I swap. I find this more helpful than the micrometer designs. I mark the tops with a Sharpie with the stem position for contact with the lands. Then you can use the tread pitch to change the seating depth into or off the lands and hold with the set screw.

I have a variety of sizing dies. I prefer the Forster "Bump" size die with bushings. It allows me to partially size the neck like all bushing dies. The part of the neck just above the shoulder is unsized and left chamber diameter while the last two tenths of the neck toward the muzzle is tuned with bushings to provide the minimum tension to keep the bullets in place but not drop on top of the powder charge.

In my chamber and using F205M primers I have found that I cannot use the maximum loads from Hodgdon data with IMR 8208 and Benchmark. I have to reduce one grain, even with HBN coated bullets. I have had pierced primers and swelled primer pockets in Nosler cases. I find that the shoulder bump die allows me to run the ragged edge and still get top accuracy. If I back off it probably maters less.

I have a Redding full length bushing die that just sits. I have Lee and Hornady full length dies that have about one use each.

I find VV N-133 outstanding in the 24 and 32 gr bullets and am using IMR 8208 for the 39 Sierras. I am open to suggestions with the 39 and 40 gr bullets. The SD and ES are not the best.

 

[Mikecr]

I use Wilson myself. But given all the praise for forster, they must be pretty good.