Gunsmithing Headspace too long? Factory Brass too short?

[Brasscow]

I had a 338 norma barrel chambered recently and when measuring the fired brass vs factory brass with a comparator gauge it seems the brass grows .011" at the shoulder. This is definitely more than any I've ever seen before and im wondering if there's a problem. My gunsmith has always been excellent, but mistakes do happen... likewise it could just be undersized factory brass. I have a no-go gauge on the way, but if that doesn't chamber and my chamber is fine, am i still safe with the brass I've now fired? Isn't it significantly more likely to seperate near the case head now? Should I be jamming or kissing the lands so i can keep the brass against the bolt face on initial firing?

Is one firing having the brass grow .011" a big enough deal to worry about? I can size it back .001 or .002 to minimize future growth.

 

[Pinecone]

1) I would contact the smith and ASK.

2) One firing for longer case is not a bit deal. There is another thread on this topic going on.

 

[DAVETOOLEY]

I can't say if there is an issue with the chamber length. I'm sure you're reloading so after the initial firing you have zero headspace. All you have to do is adjust your FL die to your chamber, which everyone should do anyway, then load and shoot. I have probably 100 wildcat reamers here in the shop and many of them either move the shoulder forward, increase the shoulder angle or change the body taper. Some do it all at the same time. It's not a problem unless you push the shoulder back to far during sizing. That can lead to case separations.

 

[Brasscow]

Thanks guys, I figured this might just be a "wildcat".

Sometimes the primers look like they jumped out of the pocket a hair before the case slammed back into the bolt face making for some ugly primers on what should be very safe loads. (88gr retumbo behind a 300gr otm)

Should i jam until ive got my brass once-fired or just say fuck it and fire away and then bump back minimally on subsequent reloads?

 

[DAVETOOLEY]

Jamming a bullet into the rifling is more important when your radically changing the body. In your case it's not that important.

 

[ugsly]

See if you can get ahold of a reamer print of the reamer that was used to cut the chamber, that may answer some questions.

Casey

 

[Brasscow]

See if you can get ahold of a reamer print of the reamer that was used to cut the chamber, that may answer some questions.

Casey

Thanks, it's my reamer and I have a copy of the print. I think it just boils down to being run in too far. The measurements of fired brass are just off.

Thanks for the help Dave, that answers my questiom perfectly.

 

[Brasscow]

Just to set the record straight, I received the no-go gauge and it would not chamber, so looks like the factory brass is just significantly under sized.

 

[xs hedspace]

So, just bump the shoulder back .001 or .002" when resizing, and it will be loverly. Don't worry, be happy.....

 

[Rem7]

I have had the exact same problem, I could not eject my reloaded case, which were new brass. I was told that Norma was under sizing their brass and the chamber was to spec. I was told to shoot them and fire form them, which I did. No issues.

 

[Brasscow]

So, just bump the shoulder back .001 or .002" when resizing, and it will be loverly. Don't worry, be happy.....

I'm aware... Like i said in the first post. Normal course of action after the first firing, just didnt know if that much growth was ok or if i was risking future head seperations.

 

[Brasscow]

I have had the exact same problem, I could not eject my reloaded case, which were new brass. I was told that Norma was under sizing their brass and the chamber was to spec. I was told to shoot them and fire form them, which I did. No issues.

Yeah... not sure why they're doing that... Fuckers.

 

[tipper]

The real problem here is what is the clearance from the bolt face and the end of the barrel, to much clearance here will cause a case head separation.

 

[my human host]

Recently ran into a similar situation with a 338 Norma. Headspace ended up at +.003 according to the go gage, but virgin brass had a significant amount of clearance. I don't recall the exact numbers offhand, but it was enough to give me a WTF moment. Turned out to be a non issue, though.