Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Reloading

Reloading Techniques For Reloading


Reply

Excessive bullet run out. How to remedy?

 
LinkBack Thread Tools Display Modes
  #1  
Old 12-07-2011, 11:47 AM
Bronze Member
 
Join Date: Feb 2010
Location: Vass, NC
Posts: 87
Excessive bullet run out. How to remedy?

I am reloading for my 338 Lapua built by Kirby Allen, and finally broke down and bought a concentricity gauge. This was an unwelcome surprise. I see a .004-.006" runout when measuring at the ogive of the loaded round. Here is my process:

Press is a Lyman T- Mag II turret press
Full length size with a Forster FL die, ensuring inside of neck is lubed
Trim to 2.711" on lyman universal trimmer
Deburr and chamfer with lyman tool
Prime fed 215M primers with hornady hand priming tool
Fill with 92.1 gr H1000
Place Berger 300gr bullet as straight as possible and place round in press with hornady 338 Lapua shell holder
Using Forster Ultra micrometer seating die
Push bullet up into die. Once it contacts the seating stem, I gentley tap and rotate the round 4 to 5 times. I then seat the bullet around 1/4 inch then rotate 180 degrees. I do this a couple times until the bullet is completely seated at a COAL 3.870"

After seated I use a Holland Concentricity gauge to measure. It runs from a few at .001 to the majority at .004" run out at the bullet's ogive.

So far I am only using new Lapua brass. I haven't gotten to reload the fire formed brass yet. After full length sizing, the brass neck run out is around .001" with a few in the .002 range. I'll neck turn once I start reloading the fire formed cases. I had to adjust the seating stem by drilling out the center so the bullet tips will not contact the stem. It only contacts the ogive now. When I set up the dies, I run the ram up to contact the bottom of the die and tighten the die lock nut hand tight.

Does anyone have a suggestion on how I should fix this. I know <.001 is the goal. Right now to straighten, I drilled a hole in a 2x4 and "bend" the bullet straight. After this, it's usually around .001" run out. Is this smart? Thanks.
Reply With Quote
  #2  
Old 12-07-2011, 12:03 PM
Platinum Member
 
Join Date: Aug 2003
Location: NC, oceanfront
Posts: 3,262
Re: Excessive bullet run out. How to remedy?

3 contributors here:
- New brass(not fire formed)
- Neck thickness variance(unturned)
- FL sizing(un-fire-forming)

You will never see <1thou runout without addressing all three.
Reply With Quote
  #3  
Old 12-07-2011, 06:06 PM
Junior Member
 
Join Date: Oct 2011
Posts: 9
Re: Excessive bullet run out. How to remedy?

SAPPER26, Mikecr is right on the money. I used to straiten my brass the way you are, never had any problem's through 1000's of round's. I now use the Hornady concentricity gauge that has A built in straitening fixture. With it you are able to get them to .0005 or under with no problem, that was $88.00 of money well spent on A very good reloading tool. I also neck size after fire forming and the next 2-4 reloadings depending on the cartridge before FL sizing. Alot of new brass is 003-006 out, you just have to clean it up one of the way's mentioned above. Good luck and good shooting to ya...
Reply With Quote
  #4  
Old 12-08-2011, 06:05 AM
Platinum Member
 
Join Date: Jan 2007
Location: PA
Posts: 1,074
Re: Excessive bullet run out. How to remedy?

Even with loading for BR, it is difficult to achieve .001" total run out consistently. I am satisfied with .000 - .004". The ultimate test is how well it shoots. Sizing dies with a ball expander are a common cause of run out. Remove the expander ball and you might see improvement. Bushing dies are great, and you can select the diameter for best bullet grip. I assume yours is a no turn neck, but turning just slightly - skimming the neck - may show improvement.

I had one of those tools that bend the neck. Sold it. Problem is that if you use the same sizer die, you will need to bend the neck with every loading, which stresses the brass.
Reply With Quote
  #5  
Old 12-08-2011, 08:11 AM
Gold Member
 
Join Date: Jan 2005
Location: Searcy, Arkansas
Posts: 700
Re: Excessive bullet run out. How to remedy?

Everyone has been giving you very good advice. I went through the same process several years ago when I "discovered" how much runout my loads had. The steps I used to correct are as follows.

I use a Forster press which floats the case base and die. You can accomplish the same thing by not tightening your die down or using an "o" ring under the die.

I removed the expander ball.

I turn necks to get them true.

You described your seating process which involves rotating the case as you are seating. I do the same and have found it helps quite a bit. You can also try the same when sizing. Some will say this work hardens the case and I have no doubt that it does to some degree. However, with the loads I typically use the problem I see most often is lose primer pockets after 6 or 7 loadings. Never had to discard a case that I could attribute to work hardening. I also anneal my necks after the 1st and 5th loading. I am also full length sizing. No problem with neck sizing, but full length works for me.

One obvious thing but I will mention it anyway.... make sure you get a good chamfer on the inside of the case neck.

Following those steps I went from 6 or 7 thou of run out to less than 1 to 2 with an occasional 3 in the mix.
Reply With Quote
  #6  
Old 12-08-2011, 08:35 AM
Platinum Member
 
Join Date: Jun 2001
Location: Potomac River
Posts: 5,057
Re: Excessive bullet run out. How to remedy?

If you have case neck runout then geometry says you will have bullet runout. I don't bother measuring bullet runout very often. I just check the necks and see if that is good. As was mentioned, how you thread the die in the press and adjust your lock ring makes a lot of difference. Sometimes it takes me three or four tires to get the die set properly.

You should check your cup in the bullet seater and make sure your VLDs are not seating off of the tip.
__________________
The Smokin Fur Rifle Club
Reply With Quote
  #7  
Old 12-08-2011, 05:35 PM
Platinum Member
 
Join Date: Dec 2005
Posts: 2,114
Re: Excessive bullet run out. How to remedy?

Quote:
Originally Posted by Buffalobob View Post
If you have case neck runout then geometry says you will have bullet runout.
Amen.

I've tried all sorts of bullet seaters including Wilson hand seating chamber types, a variety of floating collet dies for the press, even a Lyman Tong Tool with a die. All bullets tend to align with the case neck regardless of the type of tool.

Best solution is to use a full length sizing die without an expander ball and cases with neck wall thickness spread of less than .001". You can lap out the neck of a full length sizing die to 2 or 3 thousandths smaller than a loaded round's neck diameter, but it's easier to just get a bushing die from Redding or RCBS; both use the same bushings.

Bullet runout's best measured with the front V centered on the case shoulder slope. That's where rimless bottleneck cases center in the chamber when they're fired. Belted cases whose shoulder's set back a couple thousandths in a full length die do the same thing. Best part of this is any out of round of the case and/or chamber at the shoulder-body junction doesn't matter when full length sizing dies are used. Neck only sizing still allows some interference when fired case body diameters get too big. Resting the front part of the case in a V just behind the shoulder ends up with any out of round in the case at that point altering the bullet's real runout.

30 caliber rifles need no less than 2 to 3 thousandths runout. Bullet's straighten up very well and machine rest tests have proved this is enough. Any straighter's a waste of time. Especially if the loaded round's bullet just barely touches the lands when its chambered and pushed all the way forward by the firing pin like it is when its fired.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Excessive bullet run out. How to remedy?
Thread Thread Starter Forum Replies Last Post
Surgeon Remedy 338 Lapua, Leupold Mark 4 muscletrpr Guns For Sale 3 02-16-2010 03:20 PM
Excessive Headspace! Johnny5 Gunsmithing 16 12-18-2009 12:22 AM
Excessive bullet runout grumpyBD Reloading 10 12-05-2009 05:10 PM
excessive bullet runout on new 7-08 AI jmbn Reloading 5 06-18-2005 07:23 AM
Is this excessive pressure??? PrimeTime Rifles, Bullets, Barrels and Ballistics 5 02-09-2002 07:33 PM

Current Poll
Do you archery hunt for elk?
YES - 30.98%
57 Votes
NO - 53.26%
98 Votes
Not yet, but I plan to. - 15.76%
29 Votes
Total Votes: 184
You may not vote on this poll.

All times are GMT -5. The time now is 11:20 AM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC