New 6.5 Creedmoor brass headspace seems a little short

[Carey Farmer]

Do a fired case in a case gauge. If that looks good, then maybe your shellholder is too thick.
You may have to get another shellholder. - Unless the sizer die is out of whack.
There are ways to check everything:
for the rifle chamber, Go, No-go and Field gauges.
Case gauge can check both chamber and die. Etc.
You can check the depth of the shellholder with your caliper, and compare with another thinner one.

Yep, a fired case's shoulders get bumped by my die. This rifle has a Savage action and I set the headspace myself when I replaced the barrel, so I know it's good.

 

[nealm66]

I had 2 different new 30-378 brands that were10-14k short. Had me concerned but brass is doing fine so far. Had me looking at the saami though to see if maybe something wrong but just a lot of tolerance in the design.

 

[Carey Farmer]

I had 2 different new 30-378 brands that were10-14k short. Had me concerned but brass is doing fine so far. Had me looking at the saami though to see if maybe something wrong but just a lot of tolerance in the design.

Thanks nealm. Yeah, seems like belted magnums are always way short of chamber length. But on first firing they headspace off the belt, so most of the stretch probably happens near the front of the case, not at the web where case / head separation usually happens. One of the advantages of belted magnums.

 

[Harry Knutz]

Thanks nealm. Yeah, seems like belted magnums are always way short of chamber length. But on first firing they headspace off the belt, so most of the stretch probably happens near the front of the case, not at the web where case / head separation usually happens. One of the advantages of belted magnums.

Actually they always seperate right ahead of the belt, Which is why it is definitely best to neck size belted magnums, Unless it is for a BAR or something like that, Or you plan on using the brass in another rifle, Then you would need to full length size.

 

[Carey Farmer]

Actually they always seperate right ahead of the belt, Which is why it is definitely best to neck size belted magnums, Unless it is for a BAR or something like that, Or you plan on using the brass in another rifle, Then you would need to full length size.

I always felt like the initial 15 thousandths stretch really set up my belted mag cases for case head separation down the road, so I had a custom reamer made up with 10 thousandths shorter headspace. I still full length size every firing, but I try to limit the shoulder bump to zero or half a thousandth reduction from the length before going into the die. Only on the third firing of cases using that approach, so don't really know yet if I'll get much longer life.

 

[Harry Knutz]

I was shooting a 1000 yard match a long time ago and was using a 300 win mag. It was my 3rd reload on the cases and I started having case head separations which totally screwed me for that match. Bought a neck sizer for that caliber, Also changed over to RWS cases.

 

[nealm66]

I used to have problems with the necks cracking in 300 win mag. I use the amp annealer now and haven't had really any issues. I load for 3 weatherby cartridges now and seem to last as good as any other. I FL everything these days