SmallCaliberCentral

Last nite I prepted some new brass. Did my usual think. Ran them thru a full length sizer, flash holes, primer pockets, checked length and trimed.
Loaded and unfired brass..........TIR ranges on some rounds .000-.002 to as much as .006 My question is will the TIR correct it self once fired in the rifle?
How can one correct TIR on new un-fired brass.
Thanks for any help or suggestions
Later
Ray P

Ray: On that unfired brass, are you checking runout at the case neck after being F/L sized? If so, and you're getting up to .006" rounout, your die is probably not axially aligned with the shellholder in the press, and you're inducing the runout when sizing. Most unfired brass is rough in that department, and will almost always show excessive runout prior to sizing.

One way to correct this (on sized, unfired brass), and assuming your F/L sizing die is cut properly, is to raise the press ram to full height, screw the die all the way down until it just kisses the shellholder. Lower the ram just enough so that the die is not touching (at this point, you can actually move the die from side to side in the 7/8-14 threads, and feel 'rattle'), then screw the die down just a very small amount, raise the ram again so it bottoms out on the die. You'll notice the die will move in the threads, and is now aligned with the shellholder flat. Lock your lock ring on the die.

The only caveat here, is that some dies will now induce excessive headspace when sizing, so you'll need headspace gauges such as the Stoney Point set, or size a case, and see if it chambers okay. If it does, put one layer of Scotch Tape on the end of the case and see if it still chambers. If you feel resistance upon closing the bolt, you're probably okay now, and you can F/L size all your cases.

The threads on 7/8-14 presses are course threads, and have a lot of slop in them in regard to die-to-press threads. What you're attempting to do here is remove the slop by having the die go just past center of the press ram by screwing it down just pass the 'kiss' point to give the interference needed to align the die to the shellholder.

If you have too much headspace by doing this, you must use a flat spacer (I use a 4" flat machinists scale) when adjusting your die, so the shellholder will still bottom out on the die, but the spacer is used to only register a 'flat', but not have the die touch the shellholder when raised to full extension (after adjustment), that will allow the die to F/L size, but not bump the case shoulder back and create that headspace.

Sounds complicated, but it's really not once you understand the principal. Hope that's as clear as mud....

I'm far from a professional reloader, but what Rick describes sounds like something that a Forster Co-ax press would pick up on automatically with their floating shell holder. I have this press and their Match dies and they work awesome. I haven't ever checked any runouts though. My reloading techniques have not quite advanced that far...

Rick & Td-Max Thanks for the reply. I have had a little trouble reading TIR on some cases due dents in the body frome shipping and packing in the bags there sold in and fire forming is the only way know to remove them. I'd know if this was giving me a false reading. Thanks for help on the die alignment. My die is down to the shell holder with the ram in raised position. I roatate the brass 3 times while doing the necks. Being that the brass is new the only place I feel or see contact is in the neck and expander ball area.
Once fired I use my redding bushing dies and neck size only.
Thanks for reply and help.
Later
Ray P

Would a competition shell holder set from Redding also address the shell holder height?

Good call WP.....yes it would.

I may have posted this before, and if I have, sorry. If your TIR is say .006, your runout is .003. Total runout is what you are actually measuring, in other words, the total number of .001 the needle is moving. In this example, you are .003 off center. You take the TIR and divide by two to obtain the amount off center.

I'm not that good at explaining this sort of thing, but perhaps Rick or another machinist/toolmaker type can do a better job.
I may have made it even more muddled for you.

Mike

Thanks for all the help. I have checked case neck that are fired and have "0" TIR. So I know my chamber is good. Any TIR after this point is reloader induced, dies, shell holders, die threads.
New brass is another story. I have checked it right out the bag or box and have TIR up .010 before it ever saw a die.
Sorry if I'm geting anal.
My brass seams to get better with fire forming.
Later
Ray P

Ray P

You might want to consider stepping up to a Wilson Stainless Steel Bushing Neck Sizing die for your once fired brass. This isn't a full length sizing die so it will preserve the fire formed shape of your brass. This is a hand die and doesn't need a press so there is no way for it to be affected by a misalignment between the die and shell holder. You will also need the base pictured below. You drive the round into the die with a plastic faced mallet. The base provides the clearance between the die and your bench so the decapping pin can protrude. Then you simply drive the protruding decapping pin back into the die to deprime and eject the case. I know this sounds complicated but, I promise, after one round you will have the hang of it.

I have sung the praises of the Redding dies for some time now. If you use a conventional press, they ARE the way to go. Since I bought my arbor press, I have been amazed with the Wilson dies. My poor RCBS Rockchucker doesn't get much use any more for the .204. I still use it for my son's XR-100 but, he doesn't shoot nearly as much as I do.

I have found that TIR can improve during the bullet seating process as evidenced by the following numbers from this afternoon's reloading:

Neck TIR before seating:
3 cases @ .0015
22 cases @ .002
11 cases @ .0025

After seating with Redding competition die:
1 case @ .0005
10 cases @ .001
12 cases @ .0015
9 cases @ .002
4 cases @ .0025

I guess the concentricity of the bullet helps to "straighten" the neck in relationship to the case.

My firearm also fire-forms the brass to TIR of 0. I've been struggling with induced runout for several months (read as since I bought a Sinclair concentricity gage kit and Fowler electronic indicator). On new brass, I never full length size as all of my .204's are factory rifles; do the primer pockets, flash hole deburring, camfor necks, prime, charge and seat bullets specifically for fire-forming. It is then that the fun begins in trying to maintain that zero TIR. I've tried what others have suggested; neck sizing in 2 steps with progressively smaller bushings, letting the shellholder float, etc., etc. My next step is to take the most used neck bushings and put them in with my bullets to be WS2 coated.

Skipper You think the wilson is the way to go huh? I have a wilson seater and am thinking about the sizer die also. I really like the seater.