Need help getting runout more consistent.

Brosome

Machinist
Feb 17, 2014
67
10
8
#1
Need some help or advice on getting my bullet runout more consistent. I've read about 100 different threads and articles but nothing has seemed to cure the problem yet.
Out of 50 rounds I get ~30 with .003 or less runout and I'd say about 50% or so of those are right at .003 the rest between .001 and .002. So clearly I'm doing something right on at least some of those. The other ~20 out of that 50 is between .004 and .006 on the extreme. Im trying to figure out whats going wrong on those that I can fix and get down to ideally less than .001 or .002 consistently.

What I'm using/doing:
MEC Press (floating shell holder)
Lapua 308 Palma brass, necked down to 7mm, fire formed
162gr ELD-M bullets
Anneal after every firing with annealeez
Redding Full length sizing die, bumping shoulder back about .001
Sinclair neck mandrel with the .002 neck tension neck expander mandrel which I use a very fine amount of neck sizing powder on to prevent chatter/stuck cases. Then make sure is brushed out before seating.
K&M chamfer tool
Redding Seating die with the VLD micrometer stem

Runout I'm getting on the neck of my fire formed and sized brass is .0005 - .001 pretty much all day long.

So far I've tried:
Spinning the case several different ways while seating
Backing off the seater stem so it floats a bit
Backing off the whole die so it floats a bit
using lee lock rings with the o-ring
cleaning out the press and case holder
Cleaning out the seating stem and dies all together
more/less chamfer
making sure the powder is settled


And im out of ideas. It seems like my issue happens on the seating phase unless I'm mistaken, but I'm not sure what else to do to get it more consistent. Any help from reloading gurus more knowledgeable than I would be super appreciated.
 

spife7980

Full Member
Feb 10, 2017
3,494
567
113
TX
#2
What tool are you using to measure? Is it held between centers and spun or does it have the double roller wheels that the case body spins on?

Since you already have your brass segregated this would be a good oportunity to test and see if you can shoot the difference in them.
 

Brosome

Machinist
Feb 17, 2014
67
10
8
#3
Using a Sinclair tool and confirmed it by rotating a few over a vblock with a different indicator.

You're right though maybe I should shoot and see if theres actually a discernable difference at range. Wonder if im putting too much stock into concentrity for the prs type shooting im mostly interested in.
 

Stpilot12

I love lamp...
Jul 18, 2012
370
97
28
Northern Crappyfornia
#4
What Spice said.. How are you measuring? Total indicated runout or actual runout. .006" is actually .003 total runout, thats pretty good in my book. And, not trying to be a dick but.. Can you actually see and/or shoot the difference between .003 and .006??? I know I can't. It's not gonna cause you to miss a 2 moa plate at 1k yd. (my shiity wind call usually takes care of that for me)

It sounds to me like your loading process is pretty good. You could try a bushing die for sizing, I think that made a minor difference for me. I use a Forester seating die and my total runout is generally .001-.002 total.
 

Brosome

Machinist
Feb 17, 2014
67
10
8
#5
Ok that makes sense, its only half as bad as I was thinking then coming off center of case. Probably nothing that would really mater in the end I suppose just tell the ocd in me to shut up and shoot.
 
Likes: Stpilot12

tscoz

Private
Nov 8, 2017
32
0
6
67
Bluffton, SC
#10
Something very simple that you might want to try is to seat the bullet in four steps a little deeper and turning it 90 degrees each time. It’s a lot easier than it sounds and after a short time, it’ll become automatic. Using an RCBS Competition Mic Seating Die it brought bullet runout down to a consistent .001-.002 for me.
 
Jun 13, 2008
721
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#11
Something very simple that you might want to try is to seat the bullet in four steps a little deeper and turning it 90 degrees each time. It’s a lot easier than it sounds and after a short time, it’ll become automatic. Using an RCBS Competition Mic Seating Die it brought bullet runout down to a consistent .001-.002 for me.
He doesn't need to do that with a Redding Comp seater.
 
Sep 27, 2008
895
13
18
California/SFO
#15
Using an RCBS Competition Mic Seating Die it brought bullet runout down to a consistent .001-.002 for me.
Interesting, I had just the opposite experience with a RCBS Mic Competition seating die. Did a comparison test between it and a Redding Mic competition die. The Redding seater was slightly better runout than the RCBS. I did use a Lee lock ring with the O ring on the RCBS seater. It helped a bit with runout. Using a standard lock ring, the RCBS seater, runout was worse.

I was surprised at this and did some research on the Web. What I discovered was I wasn't the only one noticing this result. The RCBS Mic seater was not designed for low runout in mind, a bit different than the Redding Mic seater and the Froster Mic seater.

I already had the Redding Mic seater in 308 Win. I found a complete set of the RCBS Competition dies in 308 Win. in excellent condition at an Estate sale for about $30.00, so I bought them. The RCBS seater is an interesting design.
 

Brosome

Machinist
Feb 17, 2014
67
10
8
#18
Fine walnut tumble for about 2 hours, couple drops of turtle wax rubbing compound. .002 neck tension, bullets seating feels right, not too tight or loose. They start in pretty easy with the shallow chamfer.
 

mijp5

Gunny Sergeant
May 7, 2009
4,190
1,221
113
#19
I’ve only measured runout once in my life, and that was on a caliber I don’t shoot very often, and it was 0-1 thou. I don’t bother with my go to caliber because it cannot shoot any better and what do I do if it shows 10 thou of runout?
 

Brosome

Machinist
Feb 17, 2014
67
10
8
#21
Measuring closer to the case mouth on the bearing surface, I did run some of the more extreme ones the other day over the ogive, about .0005-.001 worse there at maybe at .006-.0075 but not very different.
 
Feb 18, 2017
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14
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#22
427 Cobra mentioned checking runout along the way. This is the best way to find out what stage does what. Start with fired, unsized case.
 
Likes: LG65CM

ezekeial

New Hide Member
May 17, 2018
12
0
1
#23
Some try squaring up their resizing dies to the shell holders. This assumes the bored hole is square to the die body. Not familiar with a Mec press, but am thinking the Forester press actually slightly floats the die? Have taken to squaring die to the fired brass, before locking the sizing die down. If using a neck expander, also might try allowing it to float slightly so it self aligns to the sized case neck. Same principle may be tried for Redding "s" dies, and allowing bushing to float slightly.
 
May 18, 2009
752
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England, ar
#24
First of all, .001-.003 is not bad. Try measuring some LC Match or Federal Gold Metal Match! .005 or .006 will show up in your group size but .001-.003 will be a lot less noticeable. When I size with a full length die I make sure the groove in the shell holder is clean and I let the deprimming rod/expander ball stay loose. I also start the bullet as straight as possible and use a slow and gentle stroke on the press handle to seat. Some reloaders will seat the bullet about half way and rotate the case 180º to finish seating. I get about the same results with a conventional seating die by being careful as I do with the competition dies. If I size with a bushing die I neck turn and can usually stay under .003. With neck turned brass, an arbor press and a Wilson die .001 is pretty easy to get.

Before you drive yourself crazy, shoot the .001-.003's and compare to the .005-.006's.
 
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