So shooting some new Nosler brass in 280AI. Savage rifle I set the headspace on. It is right. Close on go no close on nogo or tape on go. Fired brass did not grow at shoulder compared to new so its not stretching. But this spot on the web and above it is about .470. New brass is .465 or so. If I'm correct the chamber spec is .471 ish. Haven't tried to resize them yet.
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Case web expansion
- Thread starter cajun
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DoneNOut
Well-Known Member
Those are the exact numbers I have in my new vs fired 308 brass. (Lapua)
I also see .0005 expansion of primer pockets.
I also see .0005 expansion of primer pockets.
not sure what tool you're using to measure shoulder datum to access headspace growth but that line your seeing is normal with having .465 at the extractor groove and .470 at the web. it is actually a good thing because when the measurements at the .200 line and at the web are to close you could run into sizing problems. think the PRC cases and the clicker problems.
RegionRat
Well-Known Member
Cajun, time will tell and you are obviously going to get some (many) more cycles on those before The Fat Lady Sings.... but you certainly don't have any reasons to stop.
I will risk saying you don't have a worry yet based on what we know or see here and it takes several cycles to know you are in the clear with any given brass-chamber-die combo, but your photos and dimensions are unremarkable.
I will risk saying you don't have a worry yet based on what we know or see here and it takes several cycles to know you are in the clear with any given brass-chamber-die combo, but your photos and dimensions are unremarkable.
I'm using a Hornady headspace comparator to measure the shoulder dimension. I was getting the .465 number where the ring is on new brass and .471 at that spot after firing. It was actually .465 at web line just above the groove and .471 at the shiny spot after firing. I did resize some. It was a little tight but did resize. After sizing the spot was .468.
MagnumManiac
Well-Known Member
What you're seeing here is totally normal. Not all of the case expands, especially at the web juncture. Most new brass is under size by .005" if you measure it. If you keep adding powder, that expansion will get lower and wider, this is also normal.
The reason the lower section isn't shiny is because it doesn't touch anything, and the expansion line is normal.
These are fired cases with new brass, except the 300WM, this was a third firing and you can see there is more prominent expansion above the web.
Attachments
Pressure rings are normal. Case head separation is different where youd feel a ridge inside the case around there (use a bent paperclip for a feeler).
Im also using Nosler brass in a 280AI and see the same thing. Ive got 3 firings thru my brass now and going for 4.
That said, in my limited experience Nosler brass is either thinner or weaker than others so maybe the pressure ring shows up more.
Im also using Nosler brass in a 280AI and see the same thing. Ive got 3 firings thru my brass now and going for 4.
That said, in my limited experience Nosler brass is either thinner or weaker than others so maybe the pressure ring shows up more.
Are you seek much shoulder movement? Never had an Ackley. Shoulders did not move during first firing. It is headspaced on the tight side.
I also got no shoulder movement on the first firing. It was odd, but this is also my first AI experience, i was impressed with how little the shoulder moves on AI cases.
Id have to look at my notes, i dont think I noticed any movement until the 3rd firing and if that it was only .002".... My last sizing i noted to only bump the shoulder back .001".
I also noticed no case lenght growth until the 3rd firing. ...and the cases all ran at or near minimum SAAMI spec. I also noticed the rim mouth was not square to the case (parallel to the base) so I trimmed only enough to square them up. I did not trim any that measured min. Then suddenly after the 3rd firing the case length grew.
I attributed the out of square rims to Nosler brass being lower quality, and or softer brass (ive had issues with their brass failing in another caliber). I suspect the case neck thickness is uneven.
Despite all the oddities, im getting sub moa so im rolling with it. Cant find other brass anyways.... Gotta work with what I got.
Right after I bought the Nosler some Peterson hit the market. I think it's preferred.
Mikecr
Well-Known Member
What you should watch for now is popping extraction.
This will tell you if the .468 after sizing is good.
Until there is an issue, I wouldn't worry about what you can't do anything about now.
If you were filling out a chamber reamer print, I'd recommend different numbers (per my signature).
This will tell you if the .468 after sizing is good.
Until there is an issue, I wouldn't worry about what you can't do anything about now.
If you were filling out a chamber reamer print, I'd recommend different numbers (per my signature).
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...and way cheaper than Noser brass right now.
I figured it would show up but wasnt going to wait around another year. Nosler brass is good.
