Belted mag case head separation

[markm87]

Yep.
This is a Hornady issue, not a general belted magnum issue.
I have Winchester 300wm brass with 7 firings.

Man, we have RWS 300WM brass with dozens of firings. That beefy stuff and a Larry Willis belted mag collet die will get us about 12-15 firings before the primer pockets finally give out.

FC brass is 3 firings if lucky, ADG and Norma maybe 5 or so.

 

[FNSafari]

Man, we have RWS 300WM brass with dozens of firings. That beefy stuff and a Larry Willis belted mag collet die will get us about 12-15 firings before the primer pockets finally give out.

FC brass is 3 firings if lucky, ADG and Norma maybe 5 or so.

Ditto on the Larry WIllis collet die!

 

[46and2]

I've found that when I headspace my own pre-fit barrels I have never needed the LW collet die. All of the factory belted magnum barrels have need it though.

 

[SKWERLZ]

No one mentioned the trick of seating the bullets long enough to engage the lands to keep the case head on the bolt face during fire so the brass would stretch from the shoulder area instead of in front of the belt. Take a couple of factory rounds and bull the bullets and reseat them so they are jambed in the lands. Shoot them a couple times and see if they go more than 3 firings. Either use your not hot load or back off the factory load 2-3 full grains for this.

Frank

The belt should be doing that, if it’s not it’s a headspace issue.

 

[loinhunter]

First fired 7RM Peterson brass , 62.5 N165 F215M , 150 TTSX. Headspace went from 2.105” to 2.116”(max in my chamber 2.125”). Here’s the thing- each case slid into the Willis die top with no problem. No discernible head expansion. Amazing. Try if you can find.

 

[Bill K]

Belted cases do headspace on the belt, however you want to have the shoulder of the case touching the shoulder area of your chamber.
If you set that shoulder back and fire a few times, the case that way, you will develop the case ring and separation, due to the upper portion of the case stretching just like you have to much head space.
Set you sizing die to just fit snug to your fired cases and stop setting the should back.

 

[M-61]

Belted cases do headspace on the belt,

For the first couple of firings. Then it’s the shoulder that does the work.
IMO, consistent shoulder bumping lets the belt again do the headspace and you know where that brass is flowing from.
The belt is an advertising thing that at one time took off like this 6.5 Creedmoor has.
In the beginning the 300 H&H had a belt that when you look at the case you can picture why. The case has a bit more shoulder than a 45-70! Lol
The above is my opinion based on my viewpoint.