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308 run out

Hello, I have just now joined the forum and I am also new to reloading. The question I have is, me and a buddy of mine were reloading some bullets for me last night and we were checking the run out on my Hornady brass with Hornady 168 gr. BTHP and I am using RCBS dies and my run out is way out. I am not getting that good of groups at 200 yards. I also have a 22-250 and am also using the RCBS dies and the run out is good on them. Is there some way to adjust RCBS dies or do I need to just go ahead and bite the bullet and get Redding dies or better dies.
 
That is interesting. I have only had run-out issues with an old set of C&H dies. All of my RCBS stuff has been real good. I guess there is a chance that you got a bad die, but I would say that is not real likely. A friend of mine has quit using newer RCBS, as he feels that he has had more problems with them.
 
What was runout before seating the bullets? I bet if you search through the articles on this site you'll find plenty of ideas to check.

-Mac
 
You did not say how much run out you are getting. For some applications it may not be important. I did some testing many years ago and shot some of my 308 ammo with the highest run out and some that were near zero and there was no statistically significant difference for that particular application. If I have the choice between straight ammo and crooked ammo, I will take the straight ammo but will admit that for many applications it is not important.
 
If you have a smooth flat counter or table top roll your ammo across it. Watch the tips of the bullets. If they wobble up and down you will be able to see run out exceeding .003.
About 1972 I bought one of the early .25-06 in 700 Rem and it did not shoot as well as my other 700 Rems. Eventually I noticed the wobbly bullets when rolling loaded ammo across the table. I investigated the RCBS dies and found that the seater stem in the seater die had about .030 runout. This was tested in a new lathe at work. It appeared that the section of bar stock that die was made from was bent. Then entire top of the die ran out compared to the threads.
I complained to RCBS. They immediately said send them the entire die set along with sample bullets and brass. About a week later I got a new set of dies and my bullets and brass back. Ammo loaded with the new dies appeared to have no run out as measured with a Mark I eyeball. With that change in dies my rifle went from a 1.5" to 1.75" shooter to most groups around .625" at 100 yards.
 
Try this when seating Bullets.
Raise the press ram and seat the bullet only about 1/3 of the way. Lower the press ram and rotate the case in the shell holder 90 degrees. Raise the press ram and seat bullet another 1/3 of the way. Lower press ram, rotate case another 90 degrees. Raise press ram and seat bullet the remainder 1/3.

Now check your runout.
 
With all one piece dies, the culprit tends to be that the ID of the neck portion of the die is too small. The result is that the expander has too much "work" to do (has to expand up the neck too far)

Assuming that your sized cases are the culprit, and that your seated bullets are simply extending the angle of the necks, here is one thing that I have found that helps. Lube the inside of your case necks (which will require that the lube be removed after sizing) and deprime before sizing. Remove the expander assembly from the die. Short stroke cases turning a quarter turn each time, hitting top stroke four times per case. This actually goes pretty fast once you get the hang of it.

Use a expander die and mandrel to expand the necks. Prelube the mandrel before doing the first case. Go slow, feeling your way, because the case will become more crooked if the thrust exceeds the elastic limit of the shoulder, and that will make the neck more crooked in relation to the body.

Once you have expanded the neck, remove the lube. When seating your bullets, seat half way, reverse the ram, turn the partially assembled round 180 degrees and then finish seating.

If you are working with unturned necks and a factory chamber, when you get to where you want to upgrade, instead of going to a bushing FL die, I suggest a two stage sizing method, using a Lee collet die first, followed by a Redding body die set to produce the correct amount of shoulder bump.

I don't know where you are in your reloading journey, but if you do not have a way to measure your cases shoulder to head (Hornady or Sinclair "headspace" tool) and you are setting your FL dies as the manufacturer's instructions dictate, you need to do some research on how to properly set a FL die right now. Do not follow the manufacturer's instructions. They tend to be flat wrong in this area.
 
Are you neck or full length resizing ? I don't use my neck dies any more, they tended to give about 4-5 thou run out, probably due to inadequate support of the case body compared to a FL die. A good (and inexpensive) option is to use a body die to set the shoulder back then size the neck with a Lee Collet die.

Martin
 
All things being equal, if you have good numbers on the case neck after resizing, the bullet is cockeyed in the case neck. I don't care whose seater you use, this can happen.

One way to improve neck runout with common RCBS dies is to move the expander closer to the case neck when when cartridge is fully engaged in the die. Do this by running the cartridge fully into the die and start cranking the expander stem up until it makes contact, then back off about ⅛ turn; if you have too little clearance you will damage cases when you insert them. This way the expander engages while the neck is still supported and alignment is improved. Make sure you use some sort of inside neck lube as this will also help prevent distortion. Of course, when you do this you can no longer decap your cartridges and you will need to do that in a separate step.
 
You will get a million different answers on this issue...here is one more. First, remove the expander assembly from your size die and size a case. Check concentricity at the neck. If it is not dead zero then you have a die that needs to go back to whoever made it. You are beat before you start if you have a bad die.
Next, reinstall the expander assembly and leave the lock nut loose. Run a case into the die all the way. As you start to bring it out you will feel the case neck going over the expander. Stop there and lock the nut. Size a few cases with it as you just set it and check the necks for concentricity again. If your die/expander assembly is unable to produce a concentric case then you will not be able to seat a concentric bullet.
Hardcore benchrest guys tryiing to set the next world record will tell you otherwise, but .000" to plus .003" is generally considered a good tolerance for concentricity on a seated bullet.
Charge up the cases and seat a few bullets and see what you have...if they are within .003" then you should be good to go. If not, you can waste time sending the seater back, but most factory seaters just wont do it anyway. This is where you order a L.E. Wilson Straight Seater.
 
All things being equal, if you have good numbers on the case neck after resizing, the bullet is cockeyed in the case neck. I don't care whose seater you use, this can happen.

One way to improve neck runout with common RCBS dies is to move the expander closer to the case neck when when cartridge is fully engaged in the die. Do this by running the cartridge fully into the die and start cranking the expander stem up until it makes contact, then back off about ⅛ turn; if you have too little clearance you will damage cases when you insert them. This way the expander engages while the neck is still supported and alignment is improved. Make sure you use some sort of inside neck lube as this will also help prevent distortion. Of course, when you do this you can no longer decap your cartridges and you will need to do that in a separate step.

Thinkin’ Forster’s de-cap/expander stem, w/high mounted expander ball, will screw rite into a RCBS die.
 
I am going to buy a Concentricity gauge and would like to find one today. The only one around here that I can find is the Hornady Lock N Load Ammo Concentricity Gauge. My buddy has the Sinclair and I was wondering what everybody thought about the Hornady one or should I wait and get the Sinclair
 
I am going to buy a Concentricity gauge and would like to find one today. The only one around here that I can find is the Hornady Lock N Load Ammo Concentricity Gauge. My buddy has the Sinclair and I was wondering what everybody thought about the Hornady one or should I wait and get the Sinclair

I have the Sinclair, it works. NECO is a good one, and 21 century is a third.
 

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