Headspace discussion (223) [Archive] - Glock Talk

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XDRoX
10-12-2010, 21:21
I'm new to reloading rifle. Today in the mail I received a Lyman case length headspace gauge.
http://media.midwayusa.com/ProductImages/Medium/268983.jpg
I resized/deprimed a dozen or so 223 on an Orange Crusher SS with a full length Dillon die.

BTW, One Shot worked awesome.

I started the die about 3/16" from the shell holder. The cases would not gauge at all.
I slowly inched the die closer to the shell holder until the cases passed the gauge test (according to the instructions).

By the time the die was low enough to correctly size a case it was practically touching the shell holder. It rested about 1/64" above it.

So I resized a dozen or so cases. After I was finished I checked them with the case gauge. About 1/5 of them would not completely fall into the gauge.

My question is why is this happening, and is it bad to use the cases that won't case gauge. Until today I have been firing cases that obviously wouldn't gauge so I assume that you can fire them, but I'm not completely sure.

Do you guys have any light to shed on my situation?

GioaJack
10-12-2010, 21:27
This is a common problem problem with rookies but fear not, us older, wiser and more mature individuals have the correct answer;

Headspace corresponds directly to the distance from the driver's seat to the bottom of the steering wheel.

You can thank me later, going to bed, have to get up early. :whistling:


Jack

Jumper
10-12-2010, 21:56
The cases that wouldn't fall in to the guage sprung back to a little larger size when they came out of the sizing die. Brass does that. Those cases may be a little more brittle than your other cases.

They should be OK to fire. The only problem you may encounter is a little difficulty getting them in the chamber.

There are 2 ways (probably more) to solve the problem:
1) adjust your sizing die down some so the case is re-sized more. It will still spring back but since it was squeezed smaller when it springs back it will check OK in your chamber gauge (fast).
2) sort all your cases with your case gauge and adjust your die each time until they chamber (slow).

Zombie Steve
10-12-2010, 22:34
Maybe the Dillon dies are different than my Lyman or RCBS small base, but the way the instructions tell you to set those up is to go down until it touches the shell plate, then lower the ram and turn the die in another 1/8 to 1/4 turn so it cams over...

:dunno:

Never had a problem with my .223 chambering.

dudel
10-13-2010, 02:24
Maybe the Dillon dies are different than my Lyman or RCBS small base, but the way the instructions tell you to set those up is to go down until it touches the shell plate, then lower the ram and turn the die in another 1/8 to 1/4 turn so it cams over...

:dunno:

Never had a problem with my .223 chambering.

That's correct for straight walled cases; not for bottleneck cases. OP did it right. Your way, you can push the shoulder back. Push the shoulder back, and the round goes deeper into the chamber (it headspaces on the shoulder). A deep round will beat the bolt and extractor up.

dudel
10-13-2010, 02:25
What kind of brass? I've had that happen with Privi Partisan brass (PPU headstamp). Only seems to happen with that brass. I use it exclusively for the Contender.

steve4102
10-13-2010, 05:59
Maybe the Dillon dies are different than my Lyman or RCBS small base, but the way the instructions tell you to set those up is to go down until it touches the shell plate, then lower the ram and turn the die in another 1/8 to 1/4 turn so it cams over...

:dunno:

Never had a problem with my .223 chambering.

This is correct. This is the instructions that come with most of my Rifle dies, Reddings are a bit different. The die needs to at a minimum come in contact with the shell holder. There is a lot of play in the press linkage and failure to contact the shell holder can result variations in FL sized brass. Screwing the die in that additional 1/8 turn will cause the press to cam over and take the sloppy press linkage out of the picture.

RCBS instructions.
http://www.rcbs.com/guide/step5.aspx

Forster Die Instructions.
http://www.forsterproducts.com/client_images/catalog19938/pages/files/Full_Length_Sizing_Die_Instructions.pdf

The best way to set up your dies is to get a gauge like the Stony Point (Hornady) Headspace gauge. Measure a fired case and set up your die to bump the shoulder back .001-.003 and lock it down. Work hardened brass will spring back more than new brass so you may have to adjust your die in or out depending on how many times it has been fired.

XDRoX
10-13-2010, 07:28
The Dillon instructions say to touch the die to the shell holder and then back off 1/2 a turn, which is pretty much where I'm at.
I purposely started higher than that because I didn't want to over do it.

I'm not sure about which brass didn't case gauge. I think it was different brands.

I'm sure I won't have any problem with the rounds chambering as we're shooting them out of AR's. And so far they've all chambered fine.

It just bugged me that some won't case gauge. I also bought the gauge to use as a length gauge to see if the brass needs trimming. It's hard to use to test length if the case does not completely drop in.

DoctaGlockta
10-13-2010, 09:43
I've had the same thing happen with reloading 308 and using a case gauge. After full length resizing they would not drop into the gauge like some new factory brass. Even sent the dies to Lee and had them look at them. I'll reprint the letter I got back from them when I find it. Basically they said to bad so sad the die was within spec. Good luck.

fredj338
10-13-2010, 09:55
Maybe the Dillon dies are different than my Lyman or RCBS small base, but the way the instructions tell you to set those up is to go down until it touches the shell plate, then lower the ram and turn the die in another 1/8 to 1/4 turn so it cams over...

:dunno:

Never had a problem with my .223 chambering.
That is for max ful length sizing. MOst rifles will run w/ partial FL sizing. FOr an AR, I would do just as you decribed, screw the die down until it touches.

Chris, what is happening is the shoulder isn't getting pushed back far enough so the case doesn't fit the gage. Your chanber is likely slightly oversize & allowing the partial FL sized cases to function. If they work, leave the die alone & don't worry about the case gage. Case gages are usually done to min SAAMI specs.

XDRoX
10-13-2010, 10:25
That is for max ful length sizing. MOst rifles will run w/ partial FL sizing. FOr an AR, I would do just as you decribed, screw the die down until it touches.

Chris, what is happening is the shoulder isn't getting pushed back far enough so the case doesn't fit the gage. Your chanber is likely slightly oversize & allowing the partial FL sized cases to function. If they work, leave the die alone & don't worry about the case gage. Case gages are usually done to min SAAMI specs.

Thanks Fred. That makes sense.

The instructions said if a case doesn't gauge to crush it with pliers and throw it away:upeyes: I thought that was a little drastic.

dudel
10-13-2010, 16:52
Maybe the Dillon dies are different than my Lyman or RCBS small base, but the way the instructions tell you to set those up is to go down until it touches the shell plate, then lower the ram and turn the die in another 1/8 to 1/4 turn so it cams over...

:dunno:

Never had a problem with my .223 chambering.

No so with the Dillon's. http://www.dillonhelp.com/manuals/english/Dillon-Die-Instructions-May-2007.pdf

With pistol dies the sizer makes contact with the shellplate; with rifle dies, the sizer is backed off 1/2 turn after it makes contact with the shell plate. Don't know about small base dies, but Hornady and RCBS are the same.

steve4102
10-13-2010, 17:31
No so with the Dillon's. http://www.dillonhelp.com/manuals/english/Dillon-Die-Instructions-May-2007.pdf

With pistol dies the sizer makes contact with the shellplate; with rifle dies, the sizer is backed off 1/2 turn after it makes contact with the shell plate. Don't know about small base dies, but Hornady and RCBS are the same.

No not really. Yes, Dillon instructions say to touch the shell holder then back off 1/2 turn. Continue reading, #4, says to "Readjust the die for proper headspace". This means the 1/2 turn out is only a starting point and the die still needs to be fine tuned for proper headspace.

RCBS Rifle die instructions clearly state to touch the shell holder then screw the die in 1/8-1/4 turn.

specialistj
10-14-2010, 00:22
Ive had to have two of my sizing dies have material turned or ground off the bottom of the sizer. One is a newer Redding bushing die, and the other is an older Hornady Durachrome. I used an RCBS Precision Mic to dial mine in and and could never get enough sizing until I had the dies modified. It doesnt take much. Just make sure the opening is smooth around the edges after the rework. This will solve all the problems you are having. I get the impression the dies can only go down so far so you cant oversize your cases and cause excessive headspace, which leads to ruptured cases. Liability perhaps...

dudel
10-14-2010, 01:28
No not really. Yes, Dillon instructions say to touch the shell holder then back off 1/2 turn. Continue reading, #4, says to "Readjust the die for proper headspace". This means the 1/2 turn out is only a starting point and the die still needs to be fine tuned for proper headspace.

Still a different setup from pistol dies, no? That was my point.

RCBS Rifle die instructions clearly state to touch the shell holder then screw the die in 1/8-1/4 turn.

Interesting. My old RCBS .223 dies don't say that. Must be newer instructions.