OzFclass

If anyone has some unfired winchester 284 cases, could you please do me a favour and measure the case diameter just above the extractor rim and what a loaded round measures at the neck.

Thanks
Matt P

I measured a few new/unfired Win .284W cases and the case head dia. was consistent at 0.494". I don't have any 7mm projies but the neck thickness was 0.014" to 0.015" as best I could measure with my digital caliper.

Cheers,
Richard.

Matt,
I have just measured 40 or so unfired cases.
The extractor groove itself is a very consistent 0.406"
The very thickest part of the case, right above the groove (literally the widest part of the case) measured a very consistent 0.498
I neck turn my cases to 0.013", so my loaded round neck diameter of 0.310" (0.013 + 0.284 + 0.013) isnt going to tell you much. I have a 0.313 neck, so have 3 thou clearance.
My case wall micrometer gives me a pretty consistent 0.015 on the neck, but there is always the odd one at 0.014 or 0.0155
rgds
Tony

Thanks

Matt P

Matt P wrote:Thanks

Matt P

Matt,
Sorry mate, Alan just pointed out you were probably talking about Winchester brand 284 cases.......i saw the win....saw the 284....and went off and measured my Lapua cases that had been necked up.
Sorry about that.
Tony

Tony
Alan was right I was after Win brand 284 case measurements, the measurements Richard posted are a worry as the base dia is 0.494 which is what I remember from my 6.5 x 284 days before the Lapua brass came about, and I had similar issues with primer pockets due to the Lapua based reamer cuts a base @ 0.500 so when fireforming the case you go from 0.494 to 0.500 guess what happens to the primer pocket !!!!!!
I have some RWS 280 brass here so may have to try a 280 AI, I just hope it's as accurate as the 284.
Matt P

matt,
just measured some win brand 284 brass, dia adjacent to extractor groove 0.496.
neck thickness 0.014 - 0.015.
i have been running 50 0f this brass & it is so far standing up to 56 gn 2213sc with 180 bullets.
the 280 ackley is making a few eyes pop here in sa. it seems VERY accurate with high 2900 speed capability, using 2217 at what seems low pressures.
rws brass, (& norma), and the long neck of the case are 2 features.
2217 is also a low heat powder.
i recall there was a win brass spec 6.5/284 reamer lurking around here in sa some years ago which caused all manner of grief when lapua (larger diameter) brass came available. i recall split small base dies etc.
keep safe,
bruce.

matt,
just reprimed the trial lot of 50 win brass the 5th time, and pockets are as tight as new.
bruce.

Bruce
What chamber do you have ???
What did the cases measure before and after firing ???
I would prefer to stay with the 284 if the brass issue can be solved, otherwise I'm thinking about a 280 improved with a 30* shoulder.

Matt P

matt,
the chamber is my reamer.
0.5010 in front of the extractor groove.
0.476 at shoulder.
0.312 neck.
i am running necks 0.012 thick. (about 0.002 per side or 0.004 total clearance.)
new brass was 0.496 in front of extractor groove, and the brass just described is still 0.496 at that point.
in front of the web it has blown out to what is 0.499 after flsizing in my min fls die. can't tell what pre sizing measurement was because they are all sized at this moment.
i experimented with forming norma 30/06 to 7mm, and it held the same ammount of 2209 as the 284, so no gain and more work there.
the 280 case has the shoulder 0.050 forward of the 30/06, 270 etc, so a small gain there.
ackley improved, the 280 will give a bit more again.
possibly an optimum ammount for long range 7mm target shooting. and it has that lovely long neck.
it would appear to be the smallest capacity case that works with ar2217.
keep safe,
bruce.