Ideal case web sizing?

[Lonewolf74]

So I was plying with a new die yesterday and had something happen I never experienced before.

When going to size a 3 times fired case I had a heck of a time getting the case up into the die. I quickly realized it was getting stuck above the web (about 1/4 way up from the case head). With this I started taking a bunch of measurements and looking at my reamer print. Then with determination I fully sized the case by going up and down several times sizing a little more of the case body every time.

The numbers I came up with; reamer print is .588, 3X fired brass is .586, sized brass is .584, new brass is .579. These numbers all sound fine to me but holy crap does the brass go hard. I've also never took a close look at how much is being sized near the web, .002 sounds good but that's also .004 smaller than chamber diameter. Is that getting on the sloppy side?

So my question is what is the ideal amount for a case to get sized just above the web? Should it be around .002, more, less?

Thanks for your time and help
Joshua

 

[Lonewolf74]

To give a little more info and back story this is a full custom rifle and chamber, essentially a 338 Norma mag improved to my specs. Reamer is from jgs so I suspect it is spot on. The brass is Peterson 338 Norma.

I fired a few pieces of brass in the rifle 3 times with only neck sizing so I could send them to Whidden for custom hydro form and sizing die. Up to this point I've only been forming new brass and hadn't tried to size one of the 3X fired brass. When I did go to size the 3X fired brass it was super hard so I'm not sure if the die is sizing the case body and web area too much?

Thanks in advance for any help
Joshua

 

[Marky_mark]

welcome to the world of clickers

 

[Lonewolf74]

welcome to the world of clickers

If there is an issue in my system it would be the opposite of a clicker. "Clicker's" are caused by not being able to size the base down enough under chamber size. The infamous 300 PRC clicker is due to the chamber reamer spec and sizing die speck not having enough clearance between the two. In my case I'm having a very hard time sizing the brass at the base because possibly my die is sizing the base too much.

 

[Marky_mark]

I think You want your die to be sizing the base that much
One more firing and your getting a click for sure
My whidden dies werent sizing the webbing on my 300 norma enough and I was getting clickers
I bought a redding body die and it is better but the webbing will still expand to 588 but the clicks are light
This is running a very mild load too

 

[Taylorbok]

.004-.005" is normal sizing at the base.

 

[Lonewolf74]

.004-.005" is normal sizing at the base.

Thanks for the response guy's. This is what I was thinking but wanted some confirmation.

My setup is on point then, it just must be some awfully tough brass…might need to buy a bigger press!

 

[Taylorbok]

Thanks for the response guy's. This is what I was thinking but wanted some confirmation.

My setup is on point then, it just must be some awfully tough brass…might need to buy a bigger press!

What kind of lube are you running? The lanolin alcohol mixture has been working wonders for me.

 

[Lonewolf74]

Imperial wax.

What is the mix ratio you have been using and how do you apply it?

 

[Taylorbok]

Imperial wax.

What is the mix ratio you have been using and how do you apply it?

1:9 I put it in a spray bottle and with the cases in my loading block I spray it on.

 

[Mikecr]

What matters is chamber fit, not die fit.
So if your brass sizing sucks but the chambering is fine, then the die is a bad match.

 

[Taylorbok]

What matters is chamber fit, not die fit.
So if your brass sizing sucks but the chambering is fine, then the die is a bad match.

From what I understand is brass is super hard to size, chamber fit is fine.

@Lonewolf74 what press you running? I tried the M-press and it's just not up to the task of big magnums.

 

[Mikecr]

From what I understand is brass is super hard to size, chamber fit is fine.

If his chamber fit is ok, he should not be sizing, or trying to size further.

A tip that rides counter to common thinking: The solution IS NEVER 'more' clearance.
In truth, excess clearance is usually the source of problems.

From what I've seen, factory/saami chambers are sloppy by 2thou clearance at webs. My chambers are tighter,, I never FL size (anything),, and I never have chambering/extraction issues. I also don't ever have to replace cases for loosening pockets, or for any other reason.

The numbers I came up with; reamer print is .588, 3X fired brass is .586, sized brass is .584, new brass is .579.

To me, this is gross problem. Reamer print says .588, new brass measures .579 (9thou clearance!). Stop right there.
There is no chance of NOT having a problem. Imagine running with 9thou of headspace, or of neck clearance. Do you think that would work? Not for long!

Even thick/large diameter web brass yields by 1.5thou, and goes full plastic by 2thou. It might as well be tin foil by 3thou.
It doesn't spring back from there, leaving an interference fit (popping extraction). So you're then forced to size it, but if you restore big clearances again, with big sizing, you're hardening the hell out of that brass, and it wants to go right back where it's been. It will, and the brass will keep moving and you'll end up with extraction issues again, if not case head separation, or pockets too loose for use..

With that much change, you're really forming a new cartridge all together.
So whether forced to do that or chosen, it should be handled like a wildcat forming.
My advice; continue fire forming, with minimal or no sizing, until you hit chamber dimensions. Then send some of that brass (unsized) to a custom die maker. Tell him what clearances you want, where. With web area brass, I would accept no more than 1thou clearance after sizing. This at least tries to get brass operating within elasticity (it's spring back), from it's new dimension.
If that don't/won't work, and I doubt it will from that much clearance, replace the barrel with a better chamber.
Stop killing brass and wasting time with it.

 

[Taylorbok]

@Mikecr .588 at the 200 line is what I find on all 300 NM prints. he's only sizing .004" which is standard, Brass is always small from new.