.20 Practical brass forming?

I'm forming some .20 Practical brass from .223 Rem Match Lapua brass using a Redding neck sizing bushing die. After sizing down with the .233 bushing and .225 bushing I'm left with a .240"x.035-.040" ring/donut at the base of the neck. I suspect it's a result of low end SAAMI spec FL sized brass and I don't believe it will be an issue. FWIW I don't have the barrel yet so I can't chamber one.

I'm wondering if this is common? and if not should I have the base of the die or the shellholder machined down .04"?

edit:
I ran a couple of fired .223 R-P cases through the sizing die and they didn't have the donut/false shoulder. It appears that the Lapua brass must have the shoulder set back pretty far from the factory or the die's on the high end of SAAMI spec.

Need to load a dummy round (no primer/powder) and measure the outside diameter of the case neck with a bullet seated.

Why? When I know that I am going to neck down, I run JUST the expander ball into the neck, then neck turn the brass, then neck down. Most of the time, this takes care of the donut problem.

You may need to inside neck ream after sizing down the brass.

If I understand you correct, you have a false shoulder on the outside of the neck. not a donut inside the neck.

if that is the case you should be fine. If the false shoulder is caused by the lapua brass being sized to far from the factory( you say RP brass is just fine) then the false shoulder may help you with excessive headspace. I would wait on the barrel and make sure the resized lapua doesnt have too much headspace.

Steve

It's not that the donuts forming on the inside of the neck; it's more of a matter of the die not sizing enough of the neck. The shellholder and the bottom of the die are contacting before the neck is fully sized. Whether this will cause a problem with chambering and/or firing the first time is what I'm unsure of. I'm thinking I will remove .04" worth of material off the shellholder tomorrow night and see if that fixes the problem.

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Originally Posted by stevec

If I understand you correct, you have a false shoulder on the outside of the neck. not a donut inside the neck.

if that is the case you should be fine. If the false shoulder is caused by the lapua brass being sized to far from the factory( you say RP brass is just fine) then the false shoulder may help you with excessive headspace. I would wait on the barrel and make sure the resized lapua doesnt have too much headspace.

Steve

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Correct. I'm thinking the brass may need to be fireformed more than I origionally expected and the false shoulder may help that.

The waiting on the barrel part sucks. :(

Ah...gotcha.

You are FORMING donuts then. Better wait for the barrel and find out what you need.

Again, would use the script that I typed above.

If you have a standard or tight necked chamber, you are going to have pressure and chambering problems.

Redding Type S or Competition Neck sizer?

It's a type S neck sizing bushing die.

What is occuring bears a strong resemblance to the ammo in the upper (yellow tipped bullets) magazine in the picture on this page. http://www.6mmbr.com/gunweek061.html

Notice how there's a stepped or tapered portion at the neck shoulder junction. I assume the "false shoulder" may be partly due to the fact that the neck shoulder junction has to be moved farther ahead to accommidate the smaller neck diamater. It may also partly be a by product of the Redding bushing itself which is champfered to facilitate smoother sizing. I've sized down other larger caliber before and never noticed this, but those were sized in standard full lenght, non-bushing, dies.

You have the answer.
Bushing dies are not the way to go for necking down.
Buy the cheapest "non bushing" FL die you can.
Neck down your brass and fire once. Then use the bushing die from there on out.

Their isn't a non-bushing die in production for .20 practical yet.

these guys can give you more help than I can, but seem to recall that going from the .224 to .204 some like to do this in small increments of say .005. Might try that - step down from one bushing to another in steps rather than one BIG on might help. You can find Warren B (aka Fireball) over on Saubier.com, he's the guy that wrote the article on 6mmbr.com - nice guy and lots of help, might check with him.

Bet if you size in steps it will fix the issue with the Lapua brass though.

wdchuckhuntr

Well thats not real practical now is it ;D

I've burned out quite a few 204R's but no practicals so I looked quickly at the link you provided.
Just judging by the comparative pics it seems the practical indeed blows the shoulders forward (if done properly)
So the false shoulder your seeing may be necessary for ''Proper" fireforming.

I would'nt mess with anything until the barrel comes. You may be trying to remove something you actually want.
When changing the shape/length of a case while fireforming the false shoulder is quite beneficial.
Without it the case is jammed forward and forced to stretch in the rear weakening the web area.
For initial fireforming its best to have the shoulder move forward.
Brass is softer in this area and more ductile.
The web area is going to do all the stretching for the life of the case after initial fireforming.
Best to not do any major stretching there during fireforming.

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Originally Posted by wdchuckhuntr

Their isn't a non-bushing die in production for .20 practical yet.

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I bet a 20 VARTARG or VARTAG would work.

Have read on several websites not to use Lapua brass for 20 Practical,( something about neck thickness on premium brass) according to authors Win & Rem do not have these problems

http://www.6mmar.com/20_Practical.html

Domestic Brass vs Imported Brass: The 20 Practical set up we have and the related instructions is generally for use with domestic .223 brass (Winchester, Remington, U.S. Military brass, etc.). Some of the imported brass has very thick neck metal and may not be ideal for use with the 20 Practical.

The bushing dies are causing what your are describing. You need to chamber a dummy round when you get the gun to make sure the bolt will close. Then load as usual and shoot the fire formed brass should be good to go as long as you do not seat into the donut that has now moved inside the neck. I get this with my 20brs. You could turn that area but then run the risk of making it too thin.

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Originally Posted by wkt60

Have read on several websites not to use Lapua brass for 20 Practical,( something about neck thickness on premium brass) according to authors Win & Rem do not have these problems.

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I think the issue is the neckness of the neck in the reamer that was used. For best performance you could turn necks to the exact thickness you want and get rid of imperfections formed when sizing down. I use Lapua brass in my 6BR, 30BR, 22-250, 22-250AI and 308. I like to run pretty hot loads to get the most out of a cartridge. It is tough to bet Lapua IMHO if are pushing for ultimate accuracy. If you want to plink or go for varmints then easier brass prep of the Winny brass might be the best bet. Luck, Tim