What Should Fired Brass Show On V-Blocks For Case Runout?

[Buster Hemlock]

I don't think Mikecr was saying you were a liar but was really asking how you are measuring TIR. If I'm wrong then fight away. I actually was wondering myself from how it was written, are you measuring the total swing of the needle on your gauge for each individual case as you roll it through a full 360 degrees on your V-block and then taking a average of that for multiple cases or are you only checking it at 3 spots per case 120 degrees offset? TIR should be measured through a full 360 rotation for each case.

 

[Mikecr]

I did not word my concern well.
My skin is so thick that things are rarely personal to me (gruff).
So I was fishing for "my numbers are raw" or " no math in it" to clear the concern.
But I should have asked "is there any math in your numbers". In hindsight it would have been less offending.

Please forgive, and I'll take the lesson

 

[Buster Hemlock]

I did not word my concern well.
My skin is so thick that things are rarely personal to me (gruff).
So I was fishing for "my numbers are raw" or " no math in it" to clear the concern.
But I should have asked "is there any math in your numbers". In hindsight it would have been less offending.

Please forgive, and I'll take the lesson

Thick skin on the Internet/forums is a necessity because voice inflection, mannerisms and body posture while typing doesn't come across.

 

[Savage 12BVSS]

I don't think Mikecr was saying you were a liar but was really asking how you are measuring TIR. If I'm wrong then fight away. I actually was wondering myself from how it was written, are you measuring the total swing of the needle on your gauge for each individual case as you roll it through a full 360 degrees on your V-block and then taking a average of that for multiple cases or are you only checking it a 3 spots per case 120 degrees offset? TIR should be measured through a full 360 rotation for each case.

Sorry Buster, didn't realize how my statement was misleading. When I check runout on loaded case or empty brass case I go a full 360 degrees around, been using concentricity gauges for years and have always done it this way. The 120 degree twist is what I do with the case in the seater as I'm seating the bullet, lot of loader's do this automatically to offset a complete seating in one position on shellholder. Not a runout measurement at all, sorry to mention that and mislead anyone. I only mentioned it because it improved runout over one seating position.
You did a great job of explaining, and I see what's being asked. Don't take it negative in any way it's not intended in that vein. So I get 1/2 thousandth's runout out of chamber, and go thru the lee collet unchanged and end up after bullet seating 3/4 of the way between one thousandth's and zero. I call that .0008, and thats the finished product.

 

[Savage 12BVSS]

Sorry Mikecr didn't get what you were asking me, Buster explained where you guys were coming from so accept my apology for taking things wrong. Shouldn't have mentioned the seating technique and confuse things . It simply helped in a small way but I didn't explain it well. Hope all is good between us. Dave

 

[GLTaylor]

Your numbers are great! Be happy.
Rotating the cartridge while seating is obviously the way to go. Thanks for testing/comparing. I love this forum!

 

[Buster Hemlock]

The 120 degree twist makes total sense now and I do the same. If your getting .001" or less in your reloading process your doing a exceptional job. I sort rounds by runout and have my own standards on what are used as fouling rounds, rounds I gather data off and rounds I hunt or compete with. .001" is the hunting and competition number so you are crushing it with sub .001" TIR

 

[Savage 12BVSS]

Thank's gentleman, it makes me real happy, I thought it was the chamber and was ready to order a new barrel. I've got two more cartridges to tackle and hope to get them to a similar point. I credit the new press, the collet die's, and the case turning in the seating step (thats gonna take some time to become habit)

 

[J E Custom]

What runout gauge are you using that reads in .0001???

I drink a lot of coffee and I'm happy if I see .001 runout with my coffee induced shaking finger.

This is the one I have for my tool. (I like the digital because it reads in 0.0001 and is easier to differentiate in 10 thousandths). with a dial I always have to guess exactly where it is at.

J E CUSTOM

 

[jrock]

I would say you are spot on. Fired cases from all my guns are about 0.0005" or less. I do neck turn. I like the lee collect neck sizing dies but I have put them away and am only using FL sizing. Seating of the bullet (brass prep and seating together) seems to be the important part and done right, I can get <0.002" consistently.

 

[Savage 12BVSS]

Until this time I have always used forster neck or FL sizers with the expander ball in them. The cartridge I just got honed in normaly was .004-.005 sometimes as much as .006 runout on an older press with the dies and expanders. This is quite a change to the good for me. I always just worked hard to get them tweaked in on the concentricity gauge at the risk of bending necks.

 

[nicholasjohn]

Sorry Buster, didn't realize how my statement was misleading. When I check runout on loaded case or empty brass case I go a full 360 degrees around, been using concentricity gauges for years and have always done it this way. The 120 degree twist is what I do with the case in the seater as I'm seating the bullet, lot of loader's do this automatically to offset a complete seating in one position on shellholder. Not a runout measurement at all, sorry to mention that and mislead anyone. I only mentioned it because it improved runout over one seating position.
You did a great job of explaining, and I see what's being asked. Don't take it negative in any way it's not intended in that vein. So I get 1/2 thousandth's runout out of chamber, and go thru the lee collet unchanged and end up after bullet seating 3/4 of the way between one thousandth's and zero. I call that .0008, and thats the finished product.

I'm glad that you mentioned your bullet seating technique, and the 20-degree rotation. I was discussing that very thing with my buddy about a week ago, and we discussed it at great length. We've both been doing it for decades, but only because that is what we were taught. I thought about it for a while after the phone call, and a couple of questions came to mind : whether or not it makes a difference, if the difference is good or bad, and if everybody just does it because we all read the same manual forty years ago and we're just doing it because we've always done it that way.

It appears that you have tested the concept and it did make a difference, and the difference was good. Now all that remains to be done is for me to test the concept myself, and see if I get the same results you got. So, thanks for mentioning that detail in your post. This is a highly detail-oriented endeavor, and picking the fly-specks out of the pepper is what we do.

One other thing that my buddy and I discussed in that same call was the Lee Collet dies. I have used them, too, and got the same positive results you did. Seeing another vote in favor of those dies will help my buddy decide if he's going to give them a try. He's another heavy-duty detail guy, and also reads this forum.