Seating bullet problem... need help

[nwmnbowhunter]

I'm having inconsistent bullet seating in regards to runout. Different bullets, dies, and presses.

Total runout varies from .001-.01.

Seating depth is fine, neck tension is .002.

Neck runout after sizing is under .002.

I've floated shell holders, rotated cases in steps when seating... doesn't seem to help a whole lot.

Using the sinclair concentricity gauge.

Anyone solve this problem?

Thanks
John

 

[LaHunter]

What bullets? What resizing dies? What seating die? What press?

Assuming you have a quality single stage press, I would think this would be the least likely culprit.

How are you determining your neck tension?

The more specific info you can provide, the better / more useful responses you will get.

 

[Calvin45]

Can you verify that the problem isn't the projectiles? Inconsistent projectiles can't be loaded to perfectly uniform depth.

 

[ShtrRdy]

What brand of brass?

What brand and type is the seating die?

Do the case necks have a nice clean chamfer on the inside?

 

[nwmnbowhunter]

I just got the sinclair runout gauge and so i went and measured a bunch.

Neck tension i measure neck diameter after sizing them after seating.

All cases chamfered using lyman VLD chamfer

RCBS rock chucker Supreme
RCBS regular seating die
243 win Barnes 85gr ttsx - federal brass
.005
.003
.002
.007
.008
.001
.007
.002
.008
.002

Redding t-7
Rcbs matchmaster die
300 prc berger 215 - ADG brass
.001
.004
.003
.002
.003

Redding
Forster micrometer seating die
270 win 150 gr sierra gameking - peterson brass
.007
.002
.002
.002
.003
.002
.001
.001
.004
.001

same as above
270 win 130 nosler BT - federal brass
.006
.001
.004
.01

Same as above
270 win hammer 139gr - nosler brass
.002
.003
.003
.002
.002
.003

Redding t-7
RCBS Matchmaster die
300 PRC 199 Hammer ADG brass
.004
.006
.004
.004
.002
.003
.001
MEC MARKSMAN
.003
.006
.001
.002
.005
.002

these are TOTAL RUNOUT, not +/-

 

[nwmnbowhunter]

I try to measure about here. Not to close to the tip.

 

[nwmnbowhunter]

I understand runout isn't "super" important, but mine seems a little erratic.

Frustrating when i can build an arrow and broadhead 28 inches long and have less than .001 variation over the entire span but can't make a 4 inch round straight...

 

[nwmnbowhunter]

As a side note. Guys on YouTube, who i really appreciate...when they measure runout they are very very conservative in their "readings." They use +/- and never round up. So a clear .005 variation becomes just under "2 thousandths"

 

[Huntnful]

Just a quick assessment shows the hammers being the most concentric. And they are turned on a lathe. So it seems your components have the ability to seat consistently. Maybe just variations in the bullets?
How do they all actually shoot?

 

[nwmnbowhunter]

Just a quick assessment shows the hammers being the most concentric. And they are turned on a lathe. So it seems your components have the ability to seat consistently. Maybe just variations in the bullets?
How do they all actually shoot?

My 300 prc is shooting lights out to distance.

243 is a tikka and shoots under an inch at 100 yards.

Rest of them I'm still playing with

 

[Huntnful]

My 300 prc is shooting lights out to distance.

243 is a tikka and shoots under an inch at 100 yards.

Rest of them I'm still playing with

Then IDK man. There's some world class shooters that don't even worry about concentricity. The groups don't lie. That's all I would focus on, until you run into scenario where a bullet that normally shoots well, isn't shooting well, and you can narrow it down specifically to concentricity. Just my thoughts though!!

 

[nwmnbowhunter]

Then IDK man. There's some world class shooters that don't even worry about concentricity. The groups don't lie. That's all I would focus on, until you run into scenario where a bullet that normally shoots well, isn't shooting well, and you can narrow it down specifically to concentricity. Just my thoughts though!!

I don't disagree with you. But when you can easily see the bullet wobble as you spin it doesn't give great confidence.

 

[GLTaylor]

Hammer bullets are cnc turned to be consistent to .0005. Doubt it's the bullets.
Have you measured your case necks with a ball micrometer? .002 or more can come from inconsistent neck thicknesses. If case necks are inconsistent they can affect runout. I'd check that first if runout bothers you.

 

[MagnumManiac]

Did a side by side test with .001", .002", .003", .004", .006" & .008" induced runout.
At 600 no discernible difference in average group size could be seen.
Gave all my concentricity tools away and never looked at it again.
Seen a bigger difference in aggregate from a change in CBTO in a bullet batch I didn't measure than from runout.
How does a bullet that may be .007" off centre fit into a leade/throat that is .0005"-.001" larger than bullet diameter WITHOUT being straightened somewhat?
Does it stay at .007" off centre?
Have you ever measured before and after seating said bullet?
Concentricity is the least of my concerns when making precision ammo.
Concentric necks is a whole 'nuther ball game.

Cheers.