.270 WBY mystery brass

[BD]

Very Strange. I was depriming some brass today to get it ready to clean and reload when I found the case on the left in the picture. It was in a lot I last loaded in 2005. The case on the right is a normal fired case from the same lot. The primer looks normal but shoulder certainly isn't and the neck is imprinted with rifling. A .270 bullet just fits in the neck. I have no idea how this case got formed in this fashion, or how it came to be in this lot of my brass.

I do not own a rifle in any caliber larger than .270, except for a .450 Bushmaster I built just last year. I do pick up any usable brass I find on the ground, but I don't ever remember finding .270 WBY. I've bought once fired brass before. All I can figure is that this case arrived in one of the boxes of once fired stuff I bought in the past.

Any idea what sort of miss-chambering might have resulted in this?

BD

[Lloyd Smale]

if im not mistaken the neck looks a bit bigger. I could have been fired in a 7 rem mag chamber

[BD]

I'd thought about the possibility of it being fired in some larger caliber belted mag. But, how to explain the rifling marks down so close to were the neck is blown out? It seems that would require a cartridge with no throat and just about no neck.

BD

[MtGun44]

Could it have actually had the neck go up into the throat of one of the Super Short mags
with a much larger caliber? That would explain he free form unsupported expansion look
of the shoulder - which would require extremely low pressure, implying a .338 or bigger
bore diam so no real pressure was developed.

So how about firing it in a .35 or so caliber SSmag? The spherical shoulder really looks
like it never touched a chamber.

Bill

[runfiverun]

that case definately flowed forward, look at the case mouth. and where the shoulder changes shape.
i'd guess a 30 cal of sorts, maybe a 300 win mag?
measure to the shape change and compare to a 300 case like the win or norma.
the rifling impression might just be different diameters in the brass wall thickness also.
necking up 257 to 284 will often times stretch the brass unevenly resulting in thicker and thinner spots that look like rifling when the low spots fill with soot.

[BD]

I looked at the neck under the magnifier, and I think the marks on the neck are from rifling. I think the theory that it's been fired in one of the longer .30 cal mags is probably correct. The OD on the neck is .301

BD

[wiljen]

I'm gonna bet a 270 Wby fired in a 338 Win Mag chamber.

[82nd airborne]

I dont think you could close the bolt with that in a short mag.

[runfiverun]

301 is fairly common in many bores of my 308 cal guns.
and the 300 win has a very short neck so a case going into the rifling is possible.

[Lively Boy]

i looked at some pics of weatherby cases they have a rounded shoulder just like the one in your pic. see if this pic will show up? should have practiced first:shock: