Bullet runout or concentricity

[Liven The Dream]

Simple Answer: seat the bullet halfway into the case. Lower the ram, rotate the case 180* and seat.

If your original runout was .001" or less, be happy! If it is more, and my trick does not get you to that .001", get a better set of dies. I am in process on a live varmint rifle to be able to consistently hit Rockchucks at or past 1000 yards. Six inches wide, and twelve to fifteen inches tall. I will likely go with a set of Whidden dies. I have gravitated to them in the last year where 1-1.5 moa accuracy is needed. Depends on results to make the decision.

Good Luck,

ISS

Simple Answer: seat the bullet halfway into the case. Lower the ram, rotate the case 180* and seat.
I got that info from two older shooters over 40 years ago. I still do, and find my Whidden and Redding Bushing Dies just fine.

Just a note just got 200 Lapua 6BR cases. Ran then thru a Mandel Die. Start check a few for Run Out. Surprise most at .0005 a few .002.5

 

[Tedk]

No runout at all would be ideal. Wouldn't perfection be great!

I am not sure what the least acceptable runout should be. I have only recently purchased a gauge and the runout I got on my latest 308 Win loads ran from a low of .002"(4 out of 15) to .007-.008 for the rest. I think that is not good.

I am using Lee dies. I think that a better bullet seating die would go a long way toward correcting my runout problem. If so, what bullet seating die would you recommend ?

I am using Winchester Match Brass.

Can you measure the run out of the neck right before the seating operation?

 

[Bronsin]

Runout isn't a problem for me because I have machined my press and dies to make sure I have none of it. If anyone is looking for 6PPC FL Bushings dies that are crooked and can't be fixed, then I have 2 for sale............

 

[Dave M.]

I wonder how many people don't always use the same shell holder, also.

Details matter.

All of my shell holders are color coded for this exact reason.

 

[Dave M.]

Simple Answer: seat the bullet halfway into the case. Lower the ram, rotate the case 180* and seat.
I got that info from two older shooters over 40 years ago. I still do, and find my Whidden and Redding Bushing Dies just fine.

Just a note just got 200 Lapua 6BR cases. Ran then thru a Mandel Die. Start check a few for Run Out. Surprise most at .0005 a few .002.5

Been doing this for years.

 

[doublenickelcovers]

Dust covers for concentricity gauges. New business opportunity. I know I need 2. Good

Dust covers for concentricity gauges. New business opportunity. I know I need 2.

Good evening. I can certainly make dust covers for your gauges. my website is https://doublenickelcovers.bigcartel.com send me a message via my website along with pictures and I would be happy to make them for you.

Susan

 

[DShortt]

I've tested up to half of that variation with no real advantage on an F class target.

What I find so hard to wrap my head around is how a chamber and throat need to be withing 1 TENthouthanths yet we can feed it ammo that is miss aligned 100x that tolerance and it doesn't cause major issues.

So, a loaded round with run-out can apparently be corrected with a concentric chamber.
A non-concentric chamber? Matters not what your run-out is because unless the 'stars align', that bullet will leave the bore with a wobble.
Or so I see it.

 

[Bill Norris]

So, a loaded round with run-out can apparently be corrected with a concentric chamber.

That seems to be the common idea and it kind of makes sense that with that tight space it would align the bullet to whatever concentricity the chamber holds.