runout driving me nuts!!

[panzer075]

Hello all, read all I could on the subject and wanted some opinions from you guys..

I am using Lapua Brass, 308Win, all turned necks to .0145 thickness.

fired cases measure .342-.343

Upon resizing with redding S-type dies in 2 increments, first runthru with .340 bushing, and redding carbide sizing button yeilds brass with very little runout around .0005-.0015 at most.

second runthru uses same die with .336 bushing to final size, some brass runout goes up a little, maybe .0005-.001 but others go up as much as .002-.003

I am using an RCBS rockchucker press, I clean the press thoroughly before using, cleaned my shellholder also. Clean the dies, threads..so on. I have tried using o-rings under the dies..tried tightening them down the the ram, cleaned all the bushings...I am goin nuts.

funny thing is, when I seat the bullets with my redding competition seater on same setup often the runout will actually go down some, and only a few rounds when seating does runout increase.
I have had the dies checked by redding, and I am suspecting the press...but wouldnt the runout always increase if the press were bad?

I am open to any suggestions...trying to make the X-ring bigger, so I am new to all these extra measuring and benchrest type steps...

 

[johara1]

From your info. .0145 neck thickness times 2 = .029 + .308 bullet, a loaded round is .337. fired case neck is .342- .343 right? seems too much to me.
Why would size the brass twice? if a loaded round is.337 you should size the neck to ..334 or .335 or what ever it likes.......in ONE pass with out an expander, it's not needed if you turn necks.I realy think you are turning too much off, you have .005 -.006 clearance........cut it down............jim

 

[panzer075]

thanks for the reply Jim,

I am turning to .0145 more to uniform the necks...I got 400 Lapua cases all from the same lot..and the neck thickness varied from a high of .016 down to .014. The average was closer to .0145 so thats why i tunred them down to that.

I am sizing twice because on the redding site it says to never resize more than .005 in one increment..

.0343 down to .0336 is .007 in one pass...figured it was too much. and its not really an expander ball its their carbide sizing button...but I didnt know it wasnt needed if I neck turned..

 

[johara1]

This is why i say your turning to much off...you have too much clearance. your fired case should be around .339 - .340,that way your only sizing a small amount. I have no luck with redding dies,i use forster and have the neck honed to the size.run out is .001 or less.......jim

 

[JRinCo]

Try sizing them with only one pass, with the .335 bushing and see if that doesn't solve the runout problem.

 

[panzer075]

johara1,
I understand what you are saying but i cant afford to rebarrel it right now...so i am stuck with the .342 sized neck..and as far as turning off too much most necks only took off .001 or like 60% of the neck...I used a .336 bush before, and still have good neck tension using the same bushing now that i have turned the necks..

JRinCO, next time thru I will try that...but I am goin to splurge for a Harrel's songle stage press..and a new comp sizing die..my old die is just the plain ole s-type...maybe the comp sizer with a new press will help. My rockchucker is several years old..and it feels a little wobbly thru the arm and ram..there is some play in it..

I appreciate any opinions or ideas...thanks guys..

 

[johara1]

panzer, do you want to sell it? i'm loading on an a2 made in 1966 and guess what runnout isn't a problem.I don't think you press is the problem.pull them down on one pass.......jim

 

[dreever]

Before you spend the money on new press and dies,which in my opinion won't solve your problem, buy this book. It has a wealth of knowledge. I've read my copy cover to cover three times and have highlighted and made notes in the margin. It will make you a better re-loader. Sinclair carries this book also.

http://www.zediker.com/books/handloading/hlmain.html

I agree with the above comments and think if you tried unturned brass and checked the run out after initial firing and one or two neck sizes I think your run out might just be considerably less.
Perhaps your also worrying too much. I've shot some of my best scores using 'Practice' brass that I culled out because of run out. Go figure?????

Danny

 

[panzer075]

thanks for the Tip dreever,

I own the book and have already read it a few times..it is an excellent book.

As far as the new press..I needed one anyway, I have resized RUM's and 338 lapua on it...done ALOT of LC brass that was very hard to do..I have pounded out casings too many times to count in the past...so while the problem may not be entirely from the press..it really is time for a new one...the chucker will be only for hunting loads and the BIG boys..RUM's and Lapua mag..

the comp die..I always wanted to upgrade to it..I have the standard s-type now..the comp looks and works better.

I actually have several hundred loaded rounds from another 400rd lot of Lapua loaded for sniper matches..and upon checking them they fall into the same category..and actually 30-40 of them fell into runout as high as .005-.007 so the RO was actually worse on non turned, neck sized only Lapua brass from the same gun..

I do agree with all of you though..I put 15 rds into 4.4 inches on a 600yd f-class target during practice, with rounds that had between .0025-.0035 runout the other day.

that amounted to a 150-9x...it was evening practice in Albany NY, Forbes, and it was very calm..but still it shot well.
I was concerned that, at 1000yds everything changes..LOL

 

[Winchester69]

Reduce the clearance by not turning. Cull your brass with a ball mic to get uniform neck thickness.