300 WSM base sizing issue

[doverpack12]

I wanted to circle back on this.
I found a used or new but used Wilson bushing die that sizes my bases juuust enough to clear. 0.556” and under. The Wilson also fits my chamber extremely well with some but minimal sizing on all other brass dimensions when using Alex Wheelers video method to check die/chamber compatibility. 0.5565” and I start to get some feel on bolt close.

Another member found this thread with the same issue, I provided the information I had found and they ended up with the Micron die, it sizes to 0.553”. Their chamber was just a little tighter at the base than mine and 0.556” would not clear if they had gone with a Wilson.

In the meantime I saw Eric Cortina was making an expander mandrel die that also sizes the base. I ordered that when it became available. Found a piece of brass with a base measuring 0.5565” and sized with the die just about touching a shell holder. That sized down to 0.554”.

So two options out there for WSM chambers on the tighter side at the base.

 

[wind gypsy]

I wanted to circle back on this.
I found a used or new but used Wilson bushing die that sizes my bases juuust enough to clear. 0.556” and under. The Wilson also fits my chamber extremely well with some but minimal sizing on all other brass dimensions when using Alex Wheelers video method to check die/chamber compatibility. 0.5565” and I start to get some feel on bolt close.

Another member found this thread with the same issue, I provided the information I had found and they ended up with the Micron die, it sizes to 0.553”. Their chamber was just a little tighter at the base than mine and 0.556” would not clear if they had gone with a Wilson.

In the meantime I saw Eric Cortina was making an expander mandrel die that also sizes the base. I ordered that when it became available. Found a piece of brass with a base measuring 0.5565” and sized with the die just about touching a shell holder. That sized down to 0.554”.

So two options out there for WSM chambers on the tighter side at the base.

So the sticky chambering issue is addressed. Have you been able to avoid sticky bolt lift after firing with those cases that have been sized down more at the base?

 

[doverpack12]

So the sticky chambering issue is addressed. Have you been able to avoid sticky bolt lift after firing with those cases that have been sized down more at the base?

So far yes, just getting through second firing on ADG brass. Even after 1x firing some ADG need the base sized and my load is mild.

The original issue was with some Winchester brass I bought used prepped and started load work up with. Sold those when I found ADG so never had a chance to try sizing the base on the 10 or so problematic pieces.

 

[Mike D Texas]

My experience with cases that get tight at the web of your chamber has been that even if you can resize them to have plenty of clearance to fit nicely in the chamber, they are going to expand again and be tight once fired. That experience isn't with a bunch of different cartridges and brass and maybe some cases are different and that part of the brass hardens or does something to resist expanding that large again. My gut feeling is that in most cases, once a case gets sticky at the web in a given chamber, it's going to continue to be sticky every firing thereafter unless you significantly reduce chamber pressures. In that case your options are to get new brass or open up the chamber a bit larger.

You would think that’s the case but I had a 6.5 SAUM that was doing the same. I had Whidden make me a sizing die that was .005 under at the base and with the same loads it extracts easily where as previously the bolt would not pull back after opening.


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[doverpack12]

My father in law was having base sizing issues with his 270 WSM and hard chamber and extraction as a result. I ordered a second Cortina die at the same time I ordered mine. He sized 10 or so of the brass he had been using with 6-8 loads on them. He said they chambered and extracted like butter after shooting his near top end load.

 

[wind gypsy]

Im happy to be wrong in this case.