request: advice for best concentricity

[bow shot]

I'll take all the advice that that I can get. 'Thought I was doing much better, untill I started measuring with good equipment, and increasing my sample size..

Currently setup (Hornady 32gr VMax's on Hornady brass):
Lee collet neck sizer
Lee dead length seater
Old RCBS JR3 press
RCBS shell holder
Wilson (actually CH4D)trimmer
light RCBS too chamfer and de-burr

Out of the collet sizer, I'm usually very good (.001" TIR). I vary .001" to .006" after seating.
I'm searching the old threads inthe mean time...

[BabaOriley]

I'm using the Hornady dies, but the Redding Type S Match Bushing 2-Die Set is on my list. Actually, this set is on clearance at MidwayUSA right now for $105. Don't ask me why. Kind of bummed I can't even afford the clearance price right now. The next best price was Sinclair at $133.

http://www.midwayusa.com/viewProduct/?p ... ber=643793

Sounds like your Lee sizer is working well, as I've heard others say. Maybe you just want to try the Redding competition seater, which from what I've read on the net, is the best seating die on the market.

[bow shot]

Yes, I'm thinking seater issue, or perhaps non-uniform wall thickness in the neck area. Both issues imply that I've got to buy stuff, (neck turner and/or copetition seater) which is not likely for me at this time. Coming off a long string of 32 hr weeks.

I'm hoping there are details/methods that that don't involve much cash. I've tried seating in tiny increments as I rotate the cartridge, no measurable success with that one.

I do have a good caliper, I should study the wall thickness variation on a bunch, and then see how they seat. Ie., if I have 10 perfect cases (neck TIR and wall thickness uniformity after after sizing) but some of them load crooked, I guess that would incriminate my seater...

[bow shot]

...and I'm wondering... I see that neck trimmers are often listed as "outside" trimmers. It seems to me that the neck's ID would be the one that would need to be uniformed.

Can someone straighten me out on this? I may post this question by itself...

[Silverfox]

bow shot--I'm no expert, but I use a K&M outside neck turner. I use the carbide mandrel to help cut down on the donut problem AND it doesn't build up copper on the mandrel and probably stays cooler than the regular steel mandrels. Make sure you get an expandiron from the company where you purchase your neck turner.

You will need a good micrometer, NOT a caliper, if you want accurate casing neck wall thickness readings. I bought a Mitutoyo tubing mic that has interchangeable tips so they will fit inside the necks of my .172 caliber casings and on up to my bigger calibers. My mic cost under $100 about three or four years ago.

Until you get the casing neck wall thickness uniform and a bullet seater that you are sure is capable of giving you straight seating of bullets, you are probably going to be putting up with this concentricity problem. Even if you turn your casing necks, you may still have a slight difference in neck wall thickness--maybe .0005"??? If you are turning a lot of material off the necks, you would be advised to do that in two operations. I know that's a pain, but as the saying goes, "No pain, no gain!"

[Rick in Oregon]

Once you run an expander plug through a case neck as you lower the press ram, you basically have just 'uniformed' the inside of the case neck. All the variances in thickness have now been transferred to the outside of the case neck. The only way to remove them is by carefully neck turning the high spots.

For factory chambers, neck turning usually shows no reward at the target (because of SAMMI, or industry spec chambers). If your case necks vary in thickness by more than say .0015" - .002", I'd either neck turn just to make them consistent, or use a different, more consistent lot of brass for any accuracy testing, or long range shooting. You'll need to invest in a good tubing micrometer. I use Mitutoyo digital and analog mics and dial indicators....very good quality.

A trim die is just a press-mounted way of case length trimming for those without a dedicated case trimmer. If you run a sized case into a trim die, you've just reversed the neck imperfections, and put them back on the neck I.D. Best to trim after fireforming, and after all sizing has been completed, either F/L or neck sizing. HTH

[bow shot]

good, good.. I'm listening.

I have access to an ID mic at work. I'll check to see how tiny it goes. Used to use it a lot, but its been a long time.

So when I neck (or F/L size and have the expander ball in use) I'm uniformint the ID of the neck. I should therefore suspect that the non-uniformity in the necks originate in the original manufacture of the cases, and will continue in my life till I trim it ff the O.D., correct?

Did someone mention match grade in one of the older posts? Maybe it was on the Firing Line forums.

Great advice folks, again, thanks kindly...

[bow shot]

I should say that I'm measuring TIR on the cases and cartridges with a Mitutoyo .0005" dial and stand, with a steel surface plate. The case is supported at two spots with a custom V block milled for a similar purpose, measuring runout on steel pins and axels.

[Rick in Oregon]

[quote="bow shot"]

So when I neck (or F/L size and have the expander ball in use) I'm uniformint the ID of the neck. YES I should therefore suspect that the non-uniformity in the necks originate in the original manufacture of the cases, and will continue in my life till I trim it ff the O.D., correct? YES

[quote]

[Silverfox]

Looks like RIO and I were posting at about the same time.

bow shot--Your TIR measuring device sounds just fine. The mic for measuring casing neck wall thickness should look something like this one:



The ball on the end should be small enough to easily fit inside the neck of the smallest caliber casing you want to measure. Many of the reloading supply web sites don't seem to realize there are shooters out there who need mics with a ball smaller than .224"!! So, make sure the mic you order will work in your caliber casings.

Yes, IMHO, you should turn the outside of the casing neck walls. Be sure you make a slight cut down onto the shoulder, but only barely onto the shoulder. The cutting blade in my K&M neck turner is shaped so if you adjust the turner right, it will make that slight cut. Be sure you full length resize your casings and then trim them so they are all the same length--that's what enables you to do your cut down into the shoulder. If your casings aren't all the same length, you may not get into the shoulder on some and too deep on others. The expandiron is run up into the casing neck after you FL resize. That increases the ID just a tiny bit so the mandrel of the cutter will slide into the casing neck with a fairly tight fit, but not so tight that it causes so much friction that your casing neck and mandrel heats up. Use a good lubricant on the inside of the casing neck, on the mandrel and a bit on the outside of the casing neck as well. Don't turn the casing or neck turner at to high a rate of speed as that can cause excessive heat too. Excessive heat will give you casing neck walls that aren't uniform in thickness. Heat is your enemy. Like I mentioned in an earlier post, I like the carbide mandrel because it seems to stay cooler and brass doesn't seem to build up on it. It also cuts the donut out of the inside of the casing neck if you have one.

Here's a link to Sinclair, Intl. to a page with a listing of the mics they have for sale.

http://www.sinclairintl.com/prod_detail ... icrometers

[bow shot]

I'm thinking that any metal work that I do will be slow motion.

Great knowledge base here, thanks very kindly for loading me up folks.

[bow shot]

So, I shall weight the cost of purchasing tools to measure/improve my brass against the cost to purchase good brass.

Anyone that can comment or rank the quality of Hornady, Nosler, Norma, Laupua?

Currently working with Hornady, but if that is poor quality I may switch rather than fight.

[Rick in Oregon]

The highest quality brass available at this time for the 204 Ruger is Nosler. This brass is manufactured and headstamped for them by Norma. It has very consistent body and neck thickness, drilled vs. punched primer pockets (like our domestic brass) and consistent extractor grooves.

It is more expensive of course, but the time and effort saved from uniforming primer pockets, possible neck turning and other tasks to make the brass consistent is just not needed. The stuff is also weight sorted prior to shipping, so no need for that task either. I've had to put some WW cases on the lathe to properly recut the extractor grooves, or the case would not even fit into the press shellholder.

I've used a couple thousand WW 204 cases since I got my first 204 in 2006, and it took quite a while to properly uniform them all, but they're good to go now. I'd much rather just buy the good stuff right out of the gate.

In my dealings with other brands such as R-P and Hornady, let me just say that although I may someday have some more R-P cases on hand for my 204's NONE of them will ever again be Hornady! The worst/tightest primer pockets I've ever encountered in ANY caliber in over 40 years of handloading.

Lapua does not at this time produce cases for the 204.......yet.

[bow shot]

I've noticed the same thing with my Hornady cases...

is W W Winchester?

[Rick in Oregon]

Affirmative. Goes under the name "Winchester-Western", hence "WW". Available in bags of 100, and in the overall scheme of things, is a pretty good buy for the money. A precision shooter just must dedicate some time to bring those cases up to snuff.