243 wssm load info

[shooterbob]

Hey guys this is the first Ive loaded the 243 WSSM cartrides and I have a question. The rnd on the right in the pic was fired from a friends gun with 38.5 Imr 4831 right at 3000 fps with an OAL of 2.359. We are checking for an accurate load so loaded in the mid range of course. I noticed on the neck and shoulder what seems to be an abnormal amount of blowby back on the case as shown in the pic. Is this the throat being out of spec and this is fireforming to his chamber or is this normal? Ive seen the neck dirty but never this far down on the shoulder. Ive micd the case with a FL resized case and the angle of the shoulder on the fired case is different than the resized case. Im just being cautious and maybe overly so but thought Id ask here for some imput. Also this my first time using the LEE FCD so another variable thrown in.
Thanks Stacy

[Fishman]

The .243 wssm has a thick neck. Depending on the number of reloads it could need annealed. The picture makes it look like the.brass isn't trimmed square but I don't see how that could cause this.

Edit - I noticed you mentioned lee. My first die set was a lee and it sized the neck down almost 0.010 to much. They were unusable.

[Lloyd Smale]

keep a close eye on your brass around the neck area. I load for my buddys 25wssm and i sometimes see splits on brass from factory ammo after the initial firing. .

[DR Owl Creek]

The factory WSSM brass is formed from 300 WSM brass, and consequently has fairly thick case necks. From my experience, Winchester didn't bother annealing the case necks, so it was also usually very hard too. I believe this combination resulted in reports of pressure spikes with some of the rifles, which caused sticky bolt lift. At a minimum, most Winchester WSSM brass (even if new) needs to be annealed, and possibly even have the case necks turned before it is used. Once-fired brass probably has also been work hardened.

All of this can result in case necks that will not expand to seal off the neck and chamber when fired. Light loads can also contribute to the problem of sooty cases too.

Dave