request: advice for best concentricity

[bow shot]

..I'm measureing on the brass side of the olgive, hate to think what it'd be at the tip!

[bow shot]

I was cheking the ID of my case necks the other day with some of pin (plug) gauges. I know this is not a tell-all method, but I was curious about my collet die installation and was seeing if varying the ram force (within "reason") would change the neck ID (and thus, neck tension on th bullet).

I noticed that the pin gauge (.202") would seal quite nicely, and would actually "bob" in/out of the case as I applied/relaxed insertion force. Ie., the pin gauge compressed air inthe case at insertion, and the compressed air in the case would force the pin back out if I let go of it..

"hmmm" I says to myself. I wonder if this compressed air thing has some effect on the seating process, like the bullet wants to "squirt" one way or the other at the initial bullet/case "make" . Perhaps made better/worse by flat/boat tail...

So I'll likely knock the primmers out of a few, seat, measure bullet TIR, and then repeat with primers installed.

I guess its something to do...

[bow shot]

Finally got back to the bench. I bought a Wilson seating die and gave it a try. ‘Loaded up 20 rounds, and here’s the story:

1) 1x fired Nosler brass
2) Sorted brass for neck wall thicknesses variation of 0.001" or less.
3) Sorted brass for TIR of 0.0015" or less (generally very close to 0.001").
4) Not tumbled or cleaned
5) original trim verified at 1.833 +/- .001"
6) Lee Collet neck sized (on a VERY old RCBS Jr 3 press, w/ RCBS shell holder)
7) Slight VLD chamfer (just enough to remove soot from last firing) w/ Lyman tool.
Cleaned primer pocket with Lee tool
9) Did not prep flash hole
10) Installed Fed 205M primers with Lee auto prime
11) 24.0 gr Benchmark
12) Wilson seated with Hornady 40 gr VMax to 2.33”

And the bullet TIR result is (case side of the olgive):
18 @ 0.0015" or less
2 @ 0.002"

I didn’t use an arbor press, this is just squeezing the die/stem/base together by hand until I hit positive stop, which was no problem. OAL was consistent compared to the Lee and Forster seaters.

Can't wait to get back to shooting groups and varmints!!

I’ll learn to neck turn someday, I have a friends Forster trimmer with the neck turner tool and mandrel.

Still would like to bed the action…

[bow shot]

Neck turning with the Forster case trimmer (with neck turner tool accessory). Was fine, easy. Couple observations:

1) Some of the Hornady cases had up to .004" neck wall thickness variation (per individual). Ie., .009 - .0013". So trimming those to a uniform thickenss (over time) would reduce the brass to only .009". Wow. So I won't bother trimming anything with more than .002" variation.

2) Since it is a known thing that neck wall thickness varaition translates directly the wall thickness variation of the entire case, I can see why some handloaders just sort by weight, and then confirm the necks with a (tubing or anvil) mic.

[bpratl]

Finally got back to the bench. I bought a Wilson seating die and gave it a try. Can't wait to get back to shooting groups and varmints!!

+3

[bow shot]

Trying to attach a pic of the neck wall thickness variation of the Hornady brass.

Thickest at 0.013", thinnest @ 0.009". Wow

I should note that this is Hornady brass from their ammo, not the boxed brass.

the Nosler brass was very tight in neck wall thickness, but on the thin side, which (to me) is evidence that it wasy mfg'd by one house, and prepped/refined by another. That's just my guess.

[Rick in Oregon]

Nosler brass is made for them by Norma, imported here to Oregon, then it is prepped and weighed in-house as you surmised.

It's not uncommon to find uneven neck/case wall thickness, but the one you show in your photo is about the largest variation I've ever seen in a single case. I suppose this is why we have case concentricity gauges and outside neck turning tools, eh?

In my rifles I really want to extract every bit of accuracy, I use either Norma, Nosler, or Lapua cases. It should only be a matter of time until Lapua gets on the bandwagon and starts to produce .204 Ruger brass. But at least we have Norma/Nosler for now. When that happens though, our brass woes will be a thing of the past.....as long as you're willing to pay the price of admission. Remember, accuracy costs, just how accurate do you want your rifle to be?

It boils down to this: if you use domestic brass, get a full set of brass preparation tools and be prepared to spend long hours at the bench using them. If you want the best cases available, buy the excellent imported stuff from Norma or Lapua. No prep work (or very little), almost perfect consistency in regard to neck/case wall thickness variation, drilled vs. punched flash holes (no burrs) and consistent rim and extractor groove dimensions. Quality costs, period. It just depends on how much you want to spend....just like drag racing....speed costs, how fast do you want to go?

[bow shot]

I think you put it perfectly and precisely Rick.

[bow shot]

I think I mentioned earlier thread that if my brass had poor (say .004") TIR before or after sizing with the Lee Collet, that repeatedly bringing the brass back into the die while rotating the shell (AND holder) 360 degrees in small increments brought the TIR of the brass down to an acceptable level (.002" or less).

An update on that method: I found recently that just rotating the shell and holder ONCE, 180 degrees, was the superior method (most people recommend this). Neither method worked every time though.

Also, I found that if I backed the cap of the die out, and brought the brass back into the die repeatedly while screwing the cap to home, that this was more effective for reducing brass TIR. May be the same thing as backing the whole die out….

It needs to be known that this worked for me with quality brass (Nosler) having low neck wall thickness variation (0.001 – 0.0015”).

I’m sure that this is tough on the brass too, since it is being worked more...

I'll post this as a new topic also.

[Quoddy]

Loaded 75 rounds of .204 Sierra BK's yesterday, fifty 32g and twenty five 39g. I used new Norma brass and loaded them with Wilson SS hand dies and a Harrell arbor press. I happened to have them with me today at a reloading seminar and checked them on a concentricity gauge. On most there was no movement, at all, on the gauge. There were a few that made a slight needle twitch, but not enough to really move off of the zero. I'm sold on this brass and method of loading. Off to the range this week for the final test.

[bow shot]

Amen, I'm also sold on the good brass/Wilson seater combo, it did great things for me.

'But i haven't tried my other seaters (Lee and Forster) with "prestige" brass yet. May be they would seat bullets with good TIR if the brass was perfect .

I almost don't want to know at this stage of the game, LOL!!