Home Forums Reloading Big Game Rifles Lee collet brass irons...?

The redding bushing thread in the Gunwriter's forum got me to wondering about something regarding Lee collet dies. Those squeeze the case neck around a mandrel for anybody unfamiliar with them.

I usually measure case necks for thickness consistency and sort out anything whose necks vary more than about .0015" around the circumference.

Noting how the Lee die works, has anybody ever measured a neck for consistency, take a fairly inconsisten one and run it through the die set up in some big honking crusher press, then measured again? I'm wondering if all that force might actually iron out the neck and produce a more consistent thickness all around? Am also thinking that much pressure might blow out the top of the die first.

Hmm, I might have to try this sometime to see. All I have is my decades old RCBS Jr press though, and not sure that could produce enough pressure.

All you're going to do is iron in some hellacious marks from the spaces between the fingers of the collet. And no, turning the case a little bit and making another pass won't smooth them all the way out, and you'll just be making more. The indicator needle of your neck wall checker will go bump bump bump bump as you turn the case on the mandrel. Not that I've ever fiddled with this......

Yeah... but it's the INSIDE of the neck that matters... not the outside, and since Lee runs the collet against a fixed diam. madrel the ID is usually very uniform (unless your brass is shot-up and springy... but that applies to all dies)... typically within .001". I don't really give a crap how my brass looks... it's how it shoots that is important to me. Don't know if you could iron out any OD inconsictancies... but that doesn't really matter if the ID is on the money.

And, just for the record... I've never seen "hellacious" marks from the collet... some small marks yes... but nothing crazy. If you're squeezing the collet hard enough to leave marks... then you're just being excessive.

The heavy marks came from heavy handed experiments.

My take on the OD/ID thing is they both have to be good for the centerline of the bullet to point down the throat the same way for each round.

+1!!!!



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OD may matter on a tight-necked bench gun... I haven't found it to be an issue on hunting rifles... but, I've only turned necks on a couple different cartridges. And, those were all loaded on Collet Dies...

Well I use collet dies too and I assure you I have some accurate hunting rifles that can show the difference between good and bad brass so processed.

"I'm wondering if all that force might actually iron out the neck and produce a more consistent thickness all around? Am also thinking that much pressure might blow out the top of the die first."

The excellant Lee collet neck die will not shift metal around to "uniform" necks, the compression is far to low for that.

The external vertical lines on the necks, when they appear at all, are shallow and harmless. The case neck's inner bore is excellant.

Significant over-pressure on the ram WILL blow the top plug out if the die. It's designed that way, to be the "weak link" so people won't bust the top off their brittle cast iron presses if they get overly ham-fisted. The reccommended 20# of lever pressure won't do it, but 50# is likely to strip out that aluminum safey plug. (Excessive lever pressure can and will break any press.)

The Lee collet die is unique and it does have a learning curve. Those not willing to try to understand how it works AND read the instructions will be better served with a more conventional neck die.

Funny how mileage varies...

What kind of hunting groups are we talking about? I don't mean the difference between outstanding groups and groups that wouldn't be perfectly suitable for practical hunting purposes. The mileage may not vary that much.

Did an experiment once with a super accurate factory 6mm Rem... started with 50 rounds of once fired brass... measured them all, weighed them, and sorted out the best 25. Then on the top 25 I deburred flash holes, trimmed to identical length, turned the necks, uniformed pockets... etc. The other 25 I just ran through the collet die and loaded up. Groups were indistinguishable... and the largest one was in the low .5" for 5 shots and average group size was in the high .3" range... in fact, I think the unpreped brass actually shot slightly better on average than the super tuned brass. JB did an article on this some time ago with a .223 and results were similar.

Now, I'm not talking about necks that aren't straight... I'm talking about necks that may vary slightly in thickness... or have "high spots". I think we'll both agree that if it ain't straight to start with... then accuracy will suffer.

Interesting.

My latest test along these lines was with a pretty accurate 308, a Model 700 VTR. Not as good as that 6mm though by any means.

I used two sets of once fired brass, all Lake City M852 match neck sized two strokes with a Lee collet die and then body sized with a Redding die for 0.001" shoulder bump. One set of brass had neck walls consistent to 0.001" or less, while the other set had between 0.0015" and 0.002" variation. The good stuff went ten shots into 0.8" while the "culls" went into 1.1".

I think highly accurate rifle will shoot just about anything well... some need a little more TLC in the brass dept. (among other things). I reckon if one wanted to squeeze that last .1" out of a rifle... then some meticulous brass prep might git-r-done.

I often use the phrase: "The last 10% of performance is 90% of the cost"... seems applicable here.

Excellent observation. I think that we sometimes can lose sight of what we are doing and spend money needlessly.

Different guns seem to be affected by brass quality and runnout differently. Over at LR Hunting a guy had a high buck, high quality long range rig. I forget the cartridge but he had to form his brass from a parent cartridge. He said after coming out of the die the brass had .025" runnout..yup that's 25 thousandths.
The result of feeding his rifle this lowly brass to fireform was that he was consistantly shooting .75" AT 300 YDS. In fact he said he could really not tell the diff between this horrible runnout brass and that which was fully fireformed. Kinda takes the "smoke" out of things a bit.

A good reason to sort brass by neck thickness. If the brass is made off center then neither neck turning or sizing with the Lee Collet will fix it

Doesn't answer the question at hand, but I use the Lee Collet dies nearly exclusively and have found it helpful for the sake of uniformity to run it through once, then turn the case 1/3rd turn and give it a second run with equal force.

Haven't measured results so I can't say that they're doing all I need 'em to, but the groups my rifle shoots and the brass life I get is enough proof for me.

I personally feel all the steps to neck consistency are about like a dog chasing his tail in most rifles. Concentricity is much more important. The lee collets will load very concentric rounds even with slight variances in necks IME. Out of Forester, Lee, RCBS, Lyman, Hdy, and Pacific dies that I own, the Lee Collets often produce the best ammo when it comes to concentricity. The Lee followed by the Redding body die is my favorite combo even for hunting rifles.

loder

I second that...

Concentricity is where it's at... if the center ain't in the center, then everything is out of whack... seems like a good metaphor for life aswell.

OK, and let's suppose the hole in the neck is perfectly in line with the body as the collet die is supposed to produce even with less than perfect brass. And furthermore suppose the bullet was seated right down the middle of that hole. Now when you place the round in the concentricity checker, with the support points on the case body, the bullet shows very little if any runout.

But also suppose the case necks are three thousanths thicker on one side. Does that not affect how the bullet is pointed down the throat? Thick side down, higher bullet. Thin side down, lower bullet and so on.