Seating bullet problem... need help

Methow Packer

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Apr 14, 2013
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Methow, Wa
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...
Consider change your seating plug to accommodate the shape of the bullet and acquire a precision seating die such as Reading Micrometer seating die. You’ll eliminate most all your runout
 

Mike Matteson

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Jun 26, 2017
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From what I have read so far, I am wondering if he has turned his necks? He has done about everything else.
 

Philward

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Maybe it's the measuring tool, or the procedure used, or natural human variation in how you hold each case? I'd bet it's more about the bullet than anything else.
 

emp1953

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Sep 29, 2013
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Any time I develop a load with new/different components or change a component (brass, bullet) I do all the measurements, check concentricity/runout, and I write it all down. Then I chamber a few rounds and eject without firing and measure/check everything again and compare before and after. I occasionally find that the rifle's chamber fixes deviations I have in concentricity/runout. My old RCBS press had started to wear, I could wobble the ram a little bit and the 30 cal shell holder seemed to allow the case to "not be straight" as it entered the die. I replaced the press with another RCBS and all the weird measurements went away. I always checked my reloads in a Lyman Ammo Checker go-no-go block. Anyway, before and after the new press all my ammo shot to "minute of deer" at 600yds. This echoes what others are saying here that all the measurements that deviate from perfect sometimes don't make a hill of beans difference down range.
 

Jeffrey Van Zandt

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tok
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
I would switch bullets berger,hammer and try annealing your case every firing also try some dry neck lube
 

nksmfamjp

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I would make 3 key points.

1) what is your neck runout? Your bullet runout will never beat your neck run out.

2) How does your seater fit your bullet? If it wobbles, even a slight bit, it might be worth a custom seater. On YouTube, a guy named Johnnysreloadingbench seems to think this is quite important and shows it in many videos.

3) Are you neck turning? I’m not saying you should, but turned neck should have under 0.001” neck thickness variation. Unturned Winchester could have up to 0.002” neck thickness variation in a single case.

I understand runout isn't "super" important, but mine seems a little erratic.
Well, I would say TIR under 0.005” is pretty darn good, under 0.010” is good enough, over 0.02” and there is a real problem.

Under 0.01” can shoot under 0.75” groups at 100 regularly.....it matters.

I measure rolling about 0.01” up from the base, 0.05” back from the shoulder and measure 0.05-0.01” from the tip.
 

vancewalker007

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Mar 30, 2013
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I try to measure about here. Not to close to the tip.

View attachment 265523
Bullets vary so much, except the ones lathed turned, you're going to get readings all over. I never measure on the bullet only on the cases to make sure the dies are not wrecking the cases. And, like people have said here, runout in the thousandths is not be noticeable on target.

You likely don't have this issue but long secant ogive bullets for long range will seat screwy without the right seating stem.
 

COBrad

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I neck turn all my cases for my long range rifles to get runout as low as possible and neck tension as consistent as possible. My grandson runs an expander through everything instead of neck turning. We both use high end seating dies, Redding comp for me, and I seat bullets in three stages pushing it down about 1/3 and turning the case about 1/3 each time. We also use the appropriate seater stem for the bullet profile. I’m usually seeing runout in the range of .001-.002 total runout. Without turning the cases I see about double that. Is it making my ammo more accurate... not that I can tell, but I’m trying to squeeze out all the accuracy I can.
 

Mikecr

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Bullet runout itself is normally -way under 1thou. Maybe a couple 1/10ths of a thou in extreme.
Otherwise, we'd all be measuring bullet runout itself, and culling offenders before moving on to seating.

OP I notice your bullets have little for exposed bearing real estate(because of the grooves). You need to be absolutely sure that you're not on the bullet ogive(anywhere on nose curve). If you are, ever so slightly, then any fore-aft movement of the case on rotation can cause what you're seeing. This could be due to case heads slightly out of square.
 

DartonJager

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FWIW
Look up a guy named Eric Cortina on you tube he also go's by the nick name "Speedy Gonzalez" He is a national champion competitive shooter.
In one video concerning reloading techniques for obtaining maximum accuracy he said he cares nothing about run out up to IIRC 0.004" or 0.005" and considers only 5 shot 100 yard groups at or BELOW .25 MOA acceptable accuracy if his rifle shoots above. 25 MOA he he pulls that rifles barrel.
Mr Cortina produces IMO great common sense reloading video content.
Check him out
 

Rosebud

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Anniston Alabama
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 +/-
If you're groups are good, in your opinion! Stop OCD ing this.
 

nwmnbowhunter

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Nov 13, 2017
Messages
288
Bullet runout itself is normally -way under 1thou. Maybe a couple 1/10ths of a thou in extreme.
Otherwise, we'd all be measuring bullet runout itself, and culling offenders before moving on to seating.

OP I notice your bullets have little for exposed bearing real estate(because of the grooves). You need to be absolutely sure that you're not on the bullet ogive(anywhere on nose curve). If you are, ever so slightly, then any fore-aft movement of the case on rotation can cause what you're seeing. This could be due to case heads slightly out of square.
I can visibly see the wobble in the worst ones.
 

nwmnbowhunter

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Joined
Nov 13, 2017
Messages
288
FWIW
Look up a guy named Eric Cortina on you tube he also go's by the nick name "Speedy Gonzalez" He is a national champion competitive shooter.
In one video concerning reloading techniques for obtaining maximum accuracy he said he cares nothing about run out up to IIRC 0.004" or 0.005" and considers only 5 shot 100 yard groups at or BELOW .25 MOA acceptable accuracy if his rifle shoots above. 25 MOA he he pulls that rifles barrel.
Mr Cortina produces IMO great common sense reloading video content.
Check him out
I've watched most of his stuff... both he and F class John are pretty good.

I'm not denying that "if things shoot good who cares?"

It bothers me that i get so much variation.

We worry about shoulder bump, ES single digits, powder charge to .02...etc. yet i can't get a bullet seated straight consistently?

I need to get another seating stem. Then find my most straight round and I will mold the seating stem to my bullet.

I appreciate everyone's input, i have a few things to try and a few things to not worry about... haha
 

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