Shoulder bump problem? Not far enough?

[SidecarFlip]

You're right on. The shim fits between the top of the press and the die lock ring
Looks like Im going to have to find my lathe here somewhere in my junk pile and trim off about .002-.003 from the top of the shell holder

Damm!

That might be an issue. The shell holders are cased far as I know. If you want to put them in the mail, I'll surface grind them to your required dimensions....

Flatness to a millionth of an inch.

I'll extend that offer to anyone actually.

 

[Bart B]

Sully2, I know you want to size the case more by putting further up into the die. Ways to do that were mentioned; removing metal from shellholder tops or die bottoms. But there's a belt clearance issue that some folks are not aware of so I included them, too.

 

[Sully2]

That might be an issue. The shell holders are cased far as I know. If you want to put them in the mail, I'll surface grind them to your required dimensions....

Flatness to a millionth of an inch.

I'll extend that offer to anyone actually.

Cased??

 

[BillyGoatGruff]

If you want to put them in the mail, I'll surface grind them to your required dimensions....

Flatness to a millionth of an inch.

I'll extend that offer to anyone actually.

SidecarFlip
I would probably take you up on that. The more I read about the redding shell holders the more I think they do the opposite of what I need. I'm probably wrong... Plus I do not want to grind on a die. I will try to pick up a couple extra shell holders tomorrow for you to play with.
How much do you think you can take off? with in reason.

I'm getting what I need accomplished by slipping a .006 feeler gauge under the case and then sizing

Thanks,BGG

 

[Bart B]

Billy, you are right about those Comp shellholders.

 

[Broz]

SidecarFlip
I would probably take you up on that. The more I read about the redding shell holders the more I think they do the opposite of what I need. I'm probably wrong... Plus I do not want to grind on a die. I will try to pick up a couple extra shell holders tomorrow for you to play with.
How much do you think you can take off? with in reason.

I'm getting what I need accomplished by slipping a .006 feeler gauge under the case and then sizing

Thanks,BGG

Yes, they are the opposite. they limit the amount of case going into the die because most dies do too much. But if your .006" is correct, and you took .010" off the bottom of the die, the comp shell holders would put you right in the middle and allow you to adjust the shoulder head space in either direction.

You must have a short chambered rifle, long die or tall shell holder. Most likely a long die. I have only ground off a couple dies in 30+ years of reloading.

Jeff

 

[SidecarFlip]

Cased??

I believe they are case hardened (for wear). Could be wrong as I've never given one the file test.

 

[SidecarFlip]

SidecarFlip
I would probably take you up on that. The more I read about the redding shell holders the more I think they do the opposite of what I need. I'm probably wrong... Plus I do not want to grind on a die. I will try to pick up a couple extra shell holders tomorrow for you to play with.
How much do you think you can take off? with in reason.

I'm getting what I need accomplished by slipping a .006 feeler gauge under the case and then sizing

Thanks,BGG

Considering the chamfer on most shellholders, probably 0.015-20 is doable. Keep in mind that, if they are case hardened, the case will only be about 0.007 deep so going past 0.007 will expose the softer material, if they are cased, again, like I said above, I've never given one the file test.

The surface grinder was a Christmas present to myself about 10 years ago, back when I made big bucks and no, at 7500 pounds it won't fit down a chimmney....

In as much as I never load belted cases (and have to deal with the internal ridge), I grind the die base and adjust ram stroke accordingly using a headspace gage.

If 0.006 works, 0.006 and 0.007 would be my target dimensions. Understand, the top face of the shellholder will be reduced, reducing the clearance the case head has in the milled slot on the shell holder. I'm preuming that you can insert a 0.006 feeler gage and still insert the shell in the shellholder with no difficulty?

Shellholders as a rule are inherently sloppy vertically because the stress of sizing is entirely on the milled lip against the brass casehead.

 

[txsendero]

See here... your RCBS dies may be too deep.

Die Issues When Bumping Shoulders within AccurateShooter.com

 

[BrentM]

Probably a stupid question but can you measure the length of case, base to top of neck, and then bump the shoulder, and this will show up on the caliper? Example. 2.160. Bump to 2.158. Is this accurate?

 

[Bart B]

Yes, and you asked an intelligent question. And the .002" bump you exampled is about perfect for most bottleneck cases.

You'll need something that fits the same place on the case shoulder each time to make measurements accurate.

Some folks have used a 3/8ths inch inside diameter nylon or metal bushing 1/2 inch long for 30 caliber bottleneck cases, put that on the case neck against the shoulder then used a caliper to measure case head to far end of bushing. Doing this before and after full length sizing a case tells you the difference in head to shoulder measurements.

Or buy an RCBS Precision Mic or Hornady LNL case gauge to do the same thing.

 

[BrentM]

OK, great. Thanks for the info. I have some brand new lapau brass I want to measure, record, then fire form, measure, record etc. Some of my 6th shot brass is sticky now and I am either going to fix it or scrap it. Thinking scraping and doing it right this next time out.

 

[Sully2]

RCBS Techs say to bottom the die out on the shell holder and then screw the die in ANOTHER 90 degrees....and that will give a .005 shoulder bump...and the loader is designed for that over center situation.???

I hate that but guess Im going to give it a shot and see what she does???

 

[Bart B]

. . . .bottom the die out on the shell holder and then screw the die in ANOTHER 90 degrees....and that will give a .005 shoulder bump

I don't think so. Especially if the chamber shoulder's at the long end of some specs.

A 90 degree turn on the die moves it about .018". But that'll probably make the shell holder go hard against the die's bottom.

Most RCBS dies are set to bump rimless bottleneck case shoulder back to about minimum SAAMI case specs for head to shoulder dimension. On my .308 Win RCBS dies, a GO 1.630" headspace gauge head sticks out of the die's bottom .130". A fired case with 1.630" headspace sized with the .125" high shellholder touching the die's bottom will set its shoulder back .005" while the case is full into the die, then after the case comes out of the die, the shoulder will spring back a thousandth or two. It's only about .003" to .004" set back from its fired position; almost exactly SAAMI specs for minimum case headspace of 1.627".

Any fired case with greater headspace will end up with the same headspace regardless of where its shoulder was before being sized. If the fired rimless bottleneck case came from a maximum headspace chamber, it's shoulder may well get set back .010" to .015".